D Commands
This chapter describes the Cisco NX-OS security commands that begin with D.
deadtime
To configure the dead-time interval for a RADIUS or TACACS+ server group, use the deadtime command. To revert to the default, use the no form of this command.
deadtime minutes
no deadtime minutes
Syntax Description
minutes |
Number of minutes for the interval. The range is from 0 to 1440 minutes. Setting the dead-time interval to 0 disables the timer. |
Command Default
0 minutes
Command Modes
RADlUS server group configuration
TACACS+ server group configuration
Command History
|
|
|
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
You must use the feature tacacs+ command before you configure TACACS.
Examples
This example shows how to set the dead-time interval to 2 minutes for a RADIUS server group:
switch(config)# aaa group server radius RadServer
switch(config-radius)# deadtime 2
This example shows how to set the dead-time interval to 5 minutes for a TACACS+ server group:
switch(config)# aaa group server tacacs+ TacServer
switch(config-tacacs+)# deadtime 5
This example shows how to revert to the dead-time interval default:
switch(config)# aaa group server tacacs+ TacServer
switch(config-tacacs+)# no deadtime 5
Related Commands
deny icmp (IPv4)
To create an access control list (ACL) rule that denies ICMP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny icmp source destination [icmp-message | dscp dscp| log | precedence precedence | fragments]
no deny icmp source destination [icmp-message | dscp dscp | log | precedence precedence | fragments]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
icmp-message |
(Optional) Rule that matches only packets of the specified ICMP message type. This argument can be an integer from 0 to 255 or one of the keywords listed under the "ICMP Message Types" section in the "Usage Guidelines" section. |
dscp dscp |
(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
fragments |
(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments. |
log |
(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information: • • • |
precedence precedence |
(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows: • • • • • • • • • |
Command Default
A newly created IPv4 ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
IPv4 ACL configuration
Command History
|
|
|
5.2(1)N1(1) |
Added ACL logging capability. |
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•
Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address network-wildcard
This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:
switch(config-acl)# deny icmp 192.168.67.0 0.0.0.255 any
•Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address/prefix-len
This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:
switch(config-acl)# deny icmp 192.168.67.0/24 any
•Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:
host IPv4-address
This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.
This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:
switch(config-acl)# deny icmp host 192.168.67.132 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
ICMP Message Types
The icmp-message argument can be the ICMP message number, which is an integer from 0 to 255. It can also be one of the following keywords:
•administratively-prohibited—Administratively prohibited
•alternate-address—Alternate address
•conversion-error—Datagram conversion
•dod-host-prohibited—Host prohibited
•dod-net-prohibited—Net prohibited
•echo—Echo (ping)
•echo-reply—Echo reply
•general-parameter-problem—Parameter problem
•host-isolated—Host isolated
•host-precedence-unreachable—Host unreachable for precedence
•host-redirect—Host redirect
•host-tos-redirect—Host redirect for ToS
•host-tos-unreachable—Host unreachable for ToS
•host-unknown—Host unknown
•host-unreachable—Host unreachable
•information-reply—Information replies
•information-request—Information requests
•mask-reply—Mask replies
•mask-request—Mask requests
•mobile-redirect—Mobile host redirect
•net-redirect—Network redirect
•net-tos-redirect—Net redirect for ToS
•net-tos-unreachable—Network unreachable for ToS
•net-unreachable—Net unreachable
•network-unknown—Network unknown
•no-room-for-option—Parameter required but no room
•option-missing—Parameter required but not present
•packet-too-big—Fragmentation needed and DF set
•parameter-problem—All parameter problems
•port-unreachable—Port unreachable
•precedence-unreachable—Precedence cutoff
•protocol-unreachable—Protocol unreachable
•reassembly-timeout—Reassembly timeout
•redirect—All redirects
•router-advertisement—Router discovery advertisements
•router-solicitation—Router discovery solicitations
•source-quench—Source quenches
•source-route-failed—Source route failed
•time-exceeded—All time-exceeded messages
•timestamp-reply—Time-stamp replies
•timestamp-request—Time-stamp requests
•traceroute—Traceroute
•ttl-exceeded—TTL exceeded
•unreachable—All unreachables
Examples
This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all ICMP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:
switch(config)# ip access-list acl-lab-01
switch(config-acl)# deny icmp 10.23.0.0/16 10.176.0.0/16
switch(config-acl)# deny icmp 192.168.37.0/16 10.176.0.0/16
switch(config-acl)# permit ip any any
Related Commands
deny igmp (IPv4)
To create an access control list (ACL) rule that denies IGMP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny igmp source destination [igmp-message | dscp dscp | precedence precedence | fragments | log]
no deny igmp source destination [igmp-message | dscp dscp | precedence precedence | fragments | log]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
igmp-message |
(Optional) Rule that matches only packets of the specified IGMP message type. The igmp-message argument can be the IGMP message number, which is an integer from 0 to 15. It can also be one of the following keywords: • • • • • |
dscp dscp |
(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
fragments |
(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments. |
log |
(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information: • • • |
precedence precedence |
(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows: • • • • • • • • • |
Command Default
A newly created IPv4 ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
IPv4 ACL configuration
Command History
|
|
|
5.2(1)N1(1) |
Added ACL logging capability. |
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address network-wildcard
This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:
switch(config-acl)# deny igmp 192.168.67.0 0.0.0.255 any
•Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address/prefix-len
This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:
switch(config-acl)# deny igmp 192.168.67.0/24 any
•Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:
host IPv4-address
This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.
This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:
switch(config-acl)# deny igmp host 192.168.67.132 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
Examples
This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all IGMP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:
switch(config)# ip access-list acl-lab-01
switch(config-acl)# deny igmp 10.23.0.0/16 10.176.0.0/16
switch(config-acl)# deny igmp 192.168.37.0/16 10.176.0.0/16
switch(config-acl)# permit ip any any
Related Commands
deny ip (IPv4)
To create an access control list (ACL) rule that denies IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny ip source destination [dscp dscp | fragments | log | precedence precedence]
no deny ip source destination [dscp dscp | fragments | log | precedence precedence]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
dscp dscp |
(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
fragments |
(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments. |
log |
(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information: • • • |
precedence precedence |
(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows: • • • • • • • • • |
Command Default
A newly created IPv4 ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
IPv4 ACL configuration
Command History
|
|
|
5.2(1)N1(1) |
Added ACL logging capability. |
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address network-wildcard
This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:
switch(config-acl)# deny ip 192.168.67.0 0.0.0.255 any
•Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address/prefix-len
This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:
switch(config-acl)# deny ip 192.168.67.0/24 any
•Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:
host IPv4-address
This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.
This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:
switch(config-acl)# deny ip host 192.168.67.132 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
Examples
This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all IPv4 traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network:
switch(config)# ip access-list acl-lab-01
switch(config-acl)# deny ip 10.23.0.0/16 10.176.0.0/16
switch(config-acl)# deny ip 192.168.37.0/16 10.176.0.0/16
Related Commands
deny tcp (IPv4)
To create an access control list (ACL) rule that denies TCP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
General Syntax
[sequence-number] deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | established | flags | fragments | log | precedence precedence]
no deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | established | flags | fragments | log | precedence precedence]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination"section in the "Usage Guidelines" section. |
destination |
Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination"section in the "Usage Guidelines" section. |
operator port [port] |
(Optional) Rule that matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument. The port argument can be the name or the number of a TCP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "TCP Port Names" section in the "Usage Guidelines" section. A second port argument is required only when the operator argument is a range. The operator argument must be one of the following keywords: • • • • • |
portgroup portgroup |
(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument. Use the object-group ip port command to create and change IP port-group objects. |
dscp dscp |
(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
established |
(Optional) Specifies that the rule matches only packets that belong to an established TCP connection. The switch considers TCP packets with the ACK or RST bits set to belong to an established connection. |
flags |
(Optional) Rule that matches only packets that have specific TCP control bit flags set. The value of the flags argument must be one or more of the following keywords: • • • • • • |
fragments |
(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments. |
log |
(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information: • • • |
precedence precedence |
(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows: • • • • • • • • • |
Command Default
A newly created IPv4 ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
IPv4 ACL configuration
Command History
|
|
|
5.2(1)N1(1) |
Added ACL logging capability. |
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address network-wildcard
This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:
switch(config-acl)# deny tcp 192.168.67.0 0.0.0.255 any
•Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address/prefix-len
This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:
switch(config-acl)# deny tcp 192.168.67.0/24 any
•Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:
host IPv4-address
This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.
This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:
switch(config-acl)# deny tcp host 192.168.67.132 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
TCP Port Names
When you specify the protocol argument as tcp, the port argument can be a TCP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:
•bgp—Border Gateway Protocol (179)
•chargen—Character generator (19)
•cmd—Remote commands (rcmd, 514)
•daytime—Daytime (13)
•discard—Discard (9)
•domain—Domain Name Service (53)
•drip—Dynamic Routing Information Protocol (3949)
•echo—Echo (7)
•exec—EXEC (rsh, 512)
•finger—Finger (79)
•ftp—File Transfer Protocol (21)
•ftp-data—FTP data connections (2)
•gopher—Gopher (7)
•hostname—NIC hostname server (11)
•ident—Ident Protocol (113)
•irc—Internet Relay Chat (194)
•klogin—Kerberos login (543)
•kshell—Kerberos shell (544)
•login—Login (rlogin, 513)
•lpd—Printer service (515)
•nntp—Network News Transport Protocol (119)
•pim-auto-rp—PIM Auto-RP (496)
•pop2—Post Office Protocol v2 (19)
•pop3—Post Office Protocol v3 (11)
•smtp—Simple Mail Transport Protocol (25)
•sunrpc—Sun Remote Procedure Call (111)
•tacacs—TAC Access Control System (49)
•talk—Talk (517)
•telnet—Telnet (23)
•time—Time (37)
•uucp—Unix-to-Unix Copy Program (54)
•whois—WHOIS/NICNAME (43)
•www—World Wide Web (HTTP, 8)
Examples
This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all TCP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:
switch(config)# ip access-list acl-lab-01
switch(config-acl)# deny tcp 10.23.0.0/16 10.176.0.0/16
switch(config-acl)# deny tcp 192.168.37.0/16 10.176.0.0/16
switch(config-acl)# permit ip any any
Related Commands
deny udp (IPv4)
To create an access control list (ACL) rule that denies UDP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
General Syntax
[sequence-number] deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | fragments | log | precedence precedence]
no deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | fragments | log | precedence precedence
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
operator port [port] |
(Optional) Rule that matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument. The port argument can be the name or the number of a TCP or UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see "TCP Port Names" and "UDP Port Names" in the "Usage Guidelines" section. A second port argument is required only when the operator argument is a range. The operator argument must be one of the following keywords: • • • • • |
portgroup portgroup |
(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument. Use the object-group ip port command to create and change IP port-group objects. |
dscp dscp |
(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
fragments |
(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments. |
log |
(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information: • • • |
precedence precedence |
(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows: • • • • • • • • • |
Command Default
A newly created IPv4 ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
IPv4 ACL configuration
Command History
|
|
|
5.2(1)N1(1) |
Added ACL logging capability. |
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address network-wildcard
This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:
switch(config-acl)# deny udp 192.168.67.0 0.0.0.255 any
•Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv4-address/prefix-len
This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:
switch(config-acl)# deny udp 192.168.67.0/24 any
•Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:
host IPv4-address
This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.
This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:
switch(config-acl)# deny udp host 192.168.67.132 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
UDP Port Names
When you specify the protocol argument as udp, the port argument can be a UDP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:
•biff—Biff (mail notification, comsat, 512)
•bootpc—Bootstrap Protocol (BOOTP) client (68)
•bootps—Bootstrap Protocol (BOOTP) server (67)
•discard—Discard (9)
•dnsix—DNSIX security protocol auditing (195)
•domain—Domain Name Service (DNS, 53)
•echo—Echo (7)
•isakmp—Internet Security Association and Key Management Protocol (5)
•mobile-ip—Mobile IP registration (434)
•nameserver—IEN116 name service (obsolete, 42)
•netbios-dgm—NetBIOS datagram service (138)
•netbios-ns—NetBIOS name service (137)
•netbios-ss—NetBIOS session service (139)
•non500-isakmp—Internet Security Association and Key Management Protocol (45)
•ntp—Network Time Protocol (123)
•pim-auto-rp—PIM Auto-RP (496)
•rip—Routing Information Protocol (router, in.routed, 52)
•snmp—Simple Network Management Protocol (161)
•snmptrap—SNMP Traps (162)
•sunrpc—Sun Remote Procedure Call (111)
•syslog—System Logger (514)
•tacacs—TAC Access Control System (49)
•talk—Talk (517)
•tftp—Trivial File Transfer Protocol (69)
•time—Time (37)
•who—Who service (rwho, 513)
•xdmcp—X Display Manager Control Protocol (177)
Examples
This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all UDP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:
switch(config)# ip access-list acl-lab-01
switch(config-acl)# deny udp 10.23.0.0/16 10.176.0.0/16
switch(config-acl)# deny udp 192.168.37.0/16 10.176.0.0/16
switch(config-acl)# permit ip any any
Related Commands
deny icmp (IPv6)
To create an access control list (ACL) rule that denies ICMP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny icmp source destination [icmp-message | dscp dscp | flow-label flow-label-value | fragments]
no deny icmp source destination [icmp-message | dscp dscp | flow-label flow-label-value | fragments]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
icmp-message |
(Optional) ICMPv6 message type that the rule matches. This argument can be an integer from 0 to 255 or one of the keywords listed in the "ICMPv6 Message Types" section in the "Usage Guidelines" section. |
dscp dscp |
(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
flow-label flow-label-value |
(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575. |
fragments |
(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments. |
Command Default
None
Command Modes
IPv6 ACL configuration
Command History
|
|
|
4.0(1a)N1(1) |
This command was introduced. |
Usage Guidelines
A newly created IPv6 ACL contains no rules.
When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv6-address/prefix-len
This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:
switch(config-acl)# deny icmp 2001:0db8:85a3::/48 any
•Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:
host IPv6-address
This syntax is equivalent to IPv6-address/128.
This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:
switch(config-acl)# deny icmp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
ICMPv6 Message Types
The icmp-message argument can be the ICMPv6 message number, which is an integer from 0 to 255. It can also be one of the following keywords:
•beyond-scope—Destination beyond scope
•destination-unreachable—Destination address is unreachable
•echo-reply—Echo reply
•echo-request—Echo request (ping)
•header—Parameter header problems
•hop-limit—Hop limit exceeded in transit
•mld-query—Multicast Listener Discovery Query
•mld-reduction—Multicast Listener Discovery Reduction
•mld-report—Multicast Listener Discovery Report
•nd-na—Neighbor discovery neighbor advertisements
•nd-ns—Neighbor discovery neighbor solicitations
•next-header—Parameter next header problems
•no-admin—Administration prohibited destination
•no-route—No route to destination
•packet-too-big—Packet too big
•parameter-option—Parameter option problems
•parameter-problem—All parameter problems
•port-unreachable—Port unreachable
•reassembly-timeout—Reassembly timeout
•redirect—Neighbor redirect
•renum-command—Router renumbering command
•renum-result—Router renumbering result
•renum-seq-number—Router renumbering sequence number reset
•router-advertisement—Neighbor discovery router advertisements
•router-renumbering—All router renumbering
•router-solicitation—Neighbor discovery router solicitations
•time-exceeded—All time exceeded messages
•unreachable—All unreachable
Examples
This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all ICMP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:
switch# configure terminal
switch(config)# ipv6 access-list acl-lab13-ipv6
switch(config-ipv6-acl)# deny icmp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny icmp2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
Related Commands
|
|
|
|---|---|
ipv6 access-list |
Configures an IPv6 ACL. |
permit (IPv6) |
Configures a permit rule in an IPv6 ACL. |
remark |
Configures a remark in an ACL. |
time-range |
Configures a time range. |
deny ipv6 (IPv6)
To create an access control list (ACL) rule that denies IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny ipv6 source destination [dscp dscp | fragments]
no deny ipv6 source destination [dscp dscp | flow-label flow-label-value | fragments]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
dscp dscp |
(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
fragments |
(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments. |
Command Default
None
Command Modes
IPv6 ACL configuration
Command History
|
|
|
4.0(1a)N1(1) |
This command was introduced. |
Usage Guidelines
A newly created IPv6 ACL contains no rules.
When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv6-address/prefix-len
This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:
switch(config-acl)# deny ipv6 2001:0db8:85a3::/48 any
•Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:
host IPv6-address
This syntax is equivalent to IPv6-address/128.
This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:
switch(config-acl)# deny ipv6 host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
Examples
This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all IPv6 traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:
switch# configure terminal
switch(config)# ipv6 access-list acl-lab13-ipv6
switch(config-ipv6-acl)# deny ipv6 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny ipv6 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
Related Commands
|
|
|
|---|---|
ipv6 access-list |
Configures an IPv6 ACL. |
permit (IPv6) |
Configures a permit rule in an IPv6 ACL. |
remark |
Configures a remark in an ACL. |
time-range |
Configures a time range. |
deny sctp (IPv6)
To create an access control list (ACL) rule that denies SCTP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny sctp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]
no deny sctp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | log ]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
operator port [port] |
(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument. The port argument can be the name or the number of a TCP or UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see "TCP Port Names" and "UDP Port Names" in the "Usage Guidelines" section. A second port argument is required only when the operator argument is a range. The operator argument must be one of the following keywords: • • • • • |
portgroup portgroup |
(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument. Use the object-group ip port command to create and change IP port-group objects. |
dscp dscp |
(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
flow-label flow-label-value |
(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575. |
fragments |
(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments. |
Command Default
None
Command Modes
IPv6 ACL configuration
Command History
|
|
|
4.0(1a)N1(1) |
This command was introduced. |
Usage Guidelines
A newly created IPv6 ACL contains no rules.
When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv6-address/prefix-len
This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:
switch(config-acl)# deny sctp 2001:0db8:85a3::/48 any
•Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:
host IPv6-address
This syntax is equivalent to IPv6-address/128.
This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:
switch(config-acl)# deny sctp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
Examples
This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all SCTP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:
switch# configure terminal
switch(config)# ipv6 access-list acl-lab13-ipv6
switch(config-ipv6-acl)# deny sctp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny sctp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
Related Commands
|
|
|
|---|---|
ipv6 access-list |
Configures an IPv6 ACL. |
permit (IPv6) |
Configures a permit rule in an IPv6 ACL. |
remark |
Configures a remark in an ACL. |
time-range |
Configures a time range. |
deny tcp (IPv6)
To create an access control list (ACL) rule that denies TCP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
General Syntax
[sequence-number] deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | flags | established]
no deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | flags | established]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
operator port [port] |
(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument. The port argument can be the name or the number of a TCP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "TCP Port Names" section in the "Usage Guidelines" section. A second port argument is required only when the operator argument is a range. The operator argument must be one of the following keywords: • • • • • |
portgroup portgroup |
(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument. Use the object-group ip port command to create and change IP port-group objects. |
dscp dscp |
(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
flow-label flow-label-value |
(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575. |
fragments |
(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments. |
flags |
(Optional) Rule matches only packets that have specific TCP control bit flags set. The value of the flags argument must be one or more of the following keywords: • • • • • • |
established |
(Optional) Specifies that the rule matches only packets that belong to an established TCP connection. The device considers TCP packets with the ACK or RST bits set to belong to an established connection. |
Command Default
None
Command Modes
IPv6 ACL configuration
Command History
|
|
|
4.0(1a)N1(1) |
This command was introduced. |
Usage Guidelines
A newly created IPv6 ACL contains no rules.
When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv6-address/prefix-len
This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:
switch(config-acl)# deny tcp 2001:0db8:85a3::/48 any
•Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:
host IPv6-address
This syntax is equivalent to IPv6-address/128.
This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:
switch(config-acl)# deny tcp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
TCP Port Names
When you specify the protocol argument as tcp, the port argument can be a TCP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:
•bgp—Border Gateway Protocol (179)
•chargen—Character generator (19)
•cmd—Remote commands (rcmd, 514)
•daytime—Daytime (13)
•discard—Discard (9)
•domain—Domain Name Service (53)
•drip—Dynamic Routing Information Protocol (3949)
•echo—Echo (7)
•exec—Exec (rsh, 512)
•finger—Finger (79)
•ftp—File Transfer Protocol (21)
•ftp-data—FTP data connections (2)
•gopher—Gopher (7)
•hostname—NIC hostname server (11)
•ident—Ident Protocol (113)
•irc—Internet Relay Chat (194)
•klogin—Kerberos login (543)
•kshell—Kerberos shell (544)
•login—Login (rlogin, 513)
•lpd—Printer service (515)
•nntp—Network News Transport Protocol (119)
•pim-auto-rp—PIM Auto-RP (496)
•pop2—Post Office Protocol v2 (19)
•pop3—Post Office Protocol v3 (11)
•smtp—Simple Mail Transport Protocol (25)
•sunrpc—Sun Remote Procedure Call (111)
•tacacs—TAC Access Control System (49)
•talk—Talk (517)
•telnet—Telnet (23)
•time—Time (37)
•uucp—Unix-to-Unix Copy Program (54)
•whois—WHOIS/NICNAME (43)
•www—World Wide Web (HTTP, 8)
Examples
This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all TCP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:
switch# configure terminal
switch(config)# ipv6 access-list acl-lab13-ipv6
switch(config-ipv6-acl)# deny tcp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny tcp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
Related Commands
|
|
|
|---|---|
ipv6 access-list |
Configures an IPv6 ACL. |
permit (IPv6) |
Configures a permit rule in an IPv6 ACL. |
remark |
Configures a remark in an ACL. |
time-range |
Configures a time range. |
deny udp (IPv6)
To create an access control list (ACL) rule that denies UDP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.To create an IPv6 ACL rule that denies traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
General Syntax
[sequence-number] deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]
no deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]
no sequence-number
Syntax Description
sequence-number |
(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL. A sequence number can be any integer between 1 and 4294967295. By default, the first rule in an ACL has a sequence number of 10. If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule. Use the resequence command to reassign sequence numbers to rules. |
source |
Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
destination |
Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section. |
operator port [port] |
(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument. The port argument can be the name or the number of a UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "UDP Port Names" section in the "Usage Guidelines" section. A second port argument is required only when the operator argument is a range. The operator argument must be one of the following keywords: • • • • • |
portgroup portgroup |
(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument. Use the object-group ip port command to create and change IP port-group objects. |
dscp dscp |
(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords: • • • • • • • • • • • • • • • • • • • • • • |
flow-label flow-label-value |
(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575. |
fragments |
(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments. |
Command Default
None
Command Modes
IPv6 ACL configuration
Command History
|
|
|
4.0(1a)N1(1) |
This command was introduced. |
Usage Guidelines
A newly created IPv6 ACL contains no rules.
When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:
IPv6-address/prefix-len
This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:
switch(config-acl)# deny udp 2001:0db8:85a3::/48 any
•Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:
host IPv6-address
This syntax is equivalent to IPv6-address/128.
This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:
switch(config-acl)# deny udp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
•Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.
UDP Port Names
When you specify the protocol argument as udp, the port argument can be a UDP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:
•biff—Biff (mail notification, comsat, 512)
•bootpc—Bootstrap Protocol (BOOTP) client (68)
•bootps—Bootstrap Protocol (BOOTP) server (67)
•discard—Discard (9)
•dnsix—DNSIX security protocol auditing (195)
•domain—Domain Name Service (DNS, 53)
•echo—Echo (7)
•isakmp—Internet Security Association and Key Management Protocol (5)
•mobile-ip—Mobile IP registration (434)
•nameserver—IEN116 name service (obsolete, 42)
•netbios-dgm—NetBIOS datagram service (138)
•netbios-ns—NetBIOS name service (137)
•netbios-ss—NetBIOS session service (139)
•non500-isakmp—Internet Security Association and Key Management Protocol (45)
•ntp—Network Time Protocol (123)
•pim-auto-rp—PIM Auto-RP (496)
•rip—Routing Information Protocol (router, in.routed, 52)
•snmp—Simple Network Management Protocol (161)
•snmptrap—SNMP Traps (162)
•sunrpc—Sun Remote Procedure Call (111)
•syslog—System Logger (514)
•tacacs—TAC Access Control System (49)
•talk—Talk (517)
•tftp—Trivial File Transfer Protocol (69)
•time—Time (37)
•who—Who service (rwho, 513)
•xdmcp—X Display Manager Control Protocol (177)
Examples
This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all UDP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:
switch# configure terminal
switch(config)# ipv6 access-list acl-lab13-ipv6
switch(config-ipv6-acl)# deny udp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny udp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
Related Commands
|
|
|
|---|---|
ipv6 access-list |
Configures an IPv6 ACL. |
permit (IPv6) |
Configures a permit rule in an IPv6 ACL. |
remark |
Configures a remark in an ACL. |
time-range |
Configures a time range. |
deny (MAC)
To create a Media Access Control (MAC) access control list (ACL)+ rule that denies traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.
[sequence-number] deny source destination [protocol] [cos cos-value] [vlan vlan-id]
no deny source destination [protocol] [cos cos-value] [vlan vlan-id]
no sequence-number
Syntax Description
Command Default
A newly created MAC ACL contains no rules.
If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.
Command Modes
MAC ACL configuration mode
Command History
|
|
|
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
When the switch applies a MAC ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.
Source and Destination
You can specify the source and destination arguments in one of two ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:
•Address and mask—You can use a MAC address followed by a mask to specify a single address or a group of addresses. The syntax is as follows:
MAC-address MAC-mask
This example specifies the source argument with the MAC address 00c0.4f03.0a72:
switch(config-acl)# deny 00c0.4f03.0a72 0000.0000.0000 any
This example specifies the destination argument with a MAC address for all hosts with a MAC vendor code of 00603e:
switch(config-acl)# deny any 0060.3e00.0000 0000.0000.0000
•Any address—You can use the any keyword to specify that a source or destination is any MAC address. For examples of the use of the any keyword, see the examples in this section. Each of the examples shows how to specify a source or destination by using the any keyword.
MAC Protocols
The protocol argument can be the MAC protocol number or a keyword. Protocol numbers are a four-byte hexadecimal number prefixed with 0x. Valid protocol numbers are from 0x0 to 0xffff. Valid keywords are the following:
•aarp—Appletalk ARP (0x80f3)
•appletalk—Appletalk (0x809b)
•decnet-iv—DECnet Phase IV (0x6003)
•diagnostic—DEC Diagnostic Protocol (0x6005)
•etype-6000—EtherType 0x6000 (0x6000)
•etype-8042—EtherType 0x8042 (0x8042)
•ip—Internet Protocol v4 (0x0800)
•lat—DEC LAT (0x6004)
•lavc-sca—DEC LAVC, SCA (0x6007)
•mop-console—DEC MOP Remote console (0x6002)
•mop-dump—DEC MOP dump (0x6001)
•vines-echo—VINES Echo (0x0baf)
Examples
This example shows how to configure a MAC ACL named mac-ip-filter with rules that permit any non-IPv4 traffic between two groups of MAC addresses:
switch(config)# mac access-list mac-ip-filter
switch(config-mac-acl)# deny 00c0.4f00.0000 0000.00ff.ffff 0060.3e00.0000 0000.00ff.ffff ip
switch(config-mac-acl)# permit any any
Related Commands
description (user role)
To configure a description for a user role, use the description command. To revert to the default, use the no form of this command.
description text
no description
Syntax Description
text |
Text string that describes the user role. The maximum length is 128 alphanumeric characters. |
Command Default
None
Command Modes
User role configuration mode
Command History
|
|
|
4.0(0)N1(1a) |
This command was introduced. |
Usage Guidelines
You can include blank spaces in the user role description text.
Examples
This example shows how to configure the description for a user role:
switch(config)# role name MyRole
switch(config-role)# description User role for my user account.
This example shows how to remove the description from a user role:
switch(config)# role name MyRole
switch(config-role)# no description
Related Commands
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|---|---|
show role |
Displays information about the user role configuration. |
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