show bgp ipv6 neighbors
To display information about IPv6 Border Gateway Protocol (BGP) connections to neighbors, use the show bgp ipv6 neighbors command in user EXEC or privileged EXEC mode.
show bgp ipv6 {unicast | multicast} neighbors [ipv6-address] [received-routes | routes | flap-statistics | advertised-routes | paths regular-expression | dampened-routes]
Syntax Description
unicast |
Specifies IPv6 unicast address prefixes. |
multicast |
Specifies IPv6 multicast address prefixes. |
ipv6-address |
(Optional) Address of the IPv6 BGP-speaking neighbor. If you omit this argument, all IPv6 neighbors are displayed. This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons. |
received-routes |
(Optional) Displays all received routes (both accepted and rejected) from the specified neighbor. |
routes |
(Optional) Displays all routes received and accepted. This is a subset of the output from the received-routes keyword. |
flap-statistics |
(Optional) Displays flap statistics for the routes learned from the neighbor. |
advertised-routes |
(Optional) Displays all the routes the networking device advertised to the neighbor. |
paths regular-expression |
(Optional) Regular expression used to match the paths received. |
dampened-routes |
(Optional) Displays the dampened routes to the neighbor at the IP address specified. |
Command Modes
User EXEC
Privileged EXEC
Command History
Release |
Modification |
---|---|
12.2(2)T |
This command was introduced. |
12.0(21)ST |
This command was integrated into Cisco IOS Release 12.0(21)ST. |
12.0(22)S |
IPv6 capability information was added to the display. |
12.2(14)S |
This command was integrated into Cisco IOS Release 12.2(14)S. |
12.3(2)T |
The unicast keyword was added. |
12.0(26)S |
The unicast and multicast keywords were added. |
12.3(4)T |
The multicast keyword was added. |
12.2(28)SB |
This command was integrated into Cisco IOS Release 12.2(28)SB. |
12.2(25)SG |
This command was integrated into Cisco IOS Release 12.2(25)SG. |
12.2(33)SRA |
This command was integrated into Cisco IOS Release 12.2(33)SRA. |
12.2(33)SXH |
This command was integrated into Cisco IOS Release 12.2(33)SXH. |
Cisco IOS XE Release 3.1S |
This command was integrated into Cisco IOS XE Release 3.1S. |
Usage Guidelines
The show bgp ipv6 unicast neighbors and show bgp ipv6 multicast neighbors commands provide output similar to the show ip bgp neighbors command, except they are IPv6-specific.
The unicast keyword is available in Cisco IOS Release 12.3(2)T and later releases. It is not available in releases prior to 12.3(2)T. Use of the unicast keyword is mandatory starting with Cisco IOS Release 12.3(2)T.
The multicast keyword is available in Cisco IOS Release 12.0(26)S and later releases. It is not available in releases prior to 12.0(26)S. Use of either the unicast or multicast keyword is mandatory starting with Cisco IOS Release 12.0(26)S.
Examples
The following is sample output from the show bgp ipv6 neighbors command:
![]() Note |
The output is the same whether or not the unicast or multicast keyword is used. The unicast keyword is available in Cisco IOS Release 12.3(2)T and Cisco IOS Release 12.0(26)S and later releases, and the multicast keyword is available only in Cisco IOS Release 12.0(26)S and later releases. |
Router# show bgp ipv6 unicast neighbors
BGP neighbor is 3FFE:700:20:1::11, remote AS 65003, external link
Member of peer-group 6BONE for session parameters
BGP version 4, remote router ID 192.168.2.27
BGP state = Established, up for 13:40:17
Last read 00:00:09, hold time is 180, keepalive interval is 60 seconds
Neighbor capabilities:
Route refresh: advertised and received
Address family IPv6 Unicast: advertised and received
Received 31306 messages, 20 notifications, 0 in queue
Sent 14298 messages, 1 notifications, 0 in queue
Default minimum time between advertisement runs is 30 seconds
For address family: IPv6 Unicast
BGP table version 21880, neighbor version 21880
Index 1, Offset 0, Mask 0x2
Route refresh request: received 0, sent 0
6BONE peer-group member
Community attribute sent to this neighbor
Outbound path policy configured
Incoming update prefix filter list is bgp-in
Outgoing update prefix filter list is aggregate
Route map for outgoing advertisements is uni-out
77 accepted prefixes consume 4928 bytes
Prefix advertised 4303, suppressed 0, withdrawn 1328
Number of NLRIs in the update sent: max 1, min 0
1 history paths consume 64 bytes
Connections established 22; dropped 21
Last reset 13:47:05, due to BGP Notification sent, hold time expired
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Local host: 3FFE:700:20:1::12, Local port: 55345
Foreign host: 3FFE:700:20:1::11, Foreign port: 179
Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)
Event Timers (current time is 0x1A0D543C):
Timer Starts Wakeups Next
Retrans 1218 5 0x0
TimeWait 0 0 0x0
AckHold 3327 3051 0x0
SendWnd 0 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 0 0 0x0
DeadWait 0 0 0x0
iss: 1805423033 snduna: 1805489354 sndnxt: 1805489354 sndwnd: 15531
irs: 821333727 rcvnxt: 821591465 rcvwnd: 15547 delrcvwnd: 837
SRTT: 300 ms, RTTO: 303 ms, RTV: 3 ms, KRTT: 0 ms
minRTT: 8 ms, maxRTT: 300 ms, ACK hold: 200 ms
Flags: higher precedence, nagle
Datagrams (max data segment is 1420 bytes):
Rcvd: 4252 (out of order: 0), with data: 3328, total data bytes: 257737
Sent: 4445 (retransmit: 5), with data: 4445, total data bytes: 244128
The following is sample output from the show bgp ipv6 neighbors command when the router is configured to allow IPv6 traffic to be transported across an IPv4 Multiprotocol Label Switching (MPLS) network (Cisco 6PE) without any software or hardware upgrade in the IPv4 core infrastructure. A new neighbor capability is added to show that an MPLS label is assigned for each IPv6 address prefix to be advertised. 6PE uses multiprotocol BGP to provide the reachability information for the 6PE routers across the IPv4 network so that the neighbor addresses are IPv4.
Router# show bgp ipv6 unicast neighbors
BGP neighbor is 10.11.11.1, remote AS 65000, internal link
BGP version 4, remote router ID 10.11.11.1
BGP state = Established, up for 04:00:53
Last read 00:00:02, hold time is 15, keepalive interval is 5 seconds
Configured hold time is 15, keepalive interval is 10 seconds
Neighbor capabilities:
Route refresh: advertised and received(old & new)
Address family IPv6 Unicast: advertised and received
ipv6 MPLS Label capability: advertised and received
Received 67068 messages, 1 notifications, 0 in queue
Sent 67110 messages, 16 notifications, 0 in queue
Default minimum time between advertisement runs is 5 seconds
For address family: IPv6 Unicast
BGP table version 91, neighbor version 91
Index 1, Offset 0, Mask 0x2
Route refresh request: received 0, sent 0
Sending Prefix & Label
4 accepted prefixes consume 288 bytes
Prefix advertised 90, suppressed 0, withdrawn 2
Number of NLRIs in the update sent: max 3, min 0
Connections established 26; dropped 25
Last reset 04:01:20, due to BGP Notification sent, hold time expired
Connection state is ESTAB, I/O status: 1, unread input bytes: 0
Local host: 10.10.10.1, Local port: 179
Foreign host: 10.11.11.1, Foreign port: 11003
Enqueued packets for retransmit: 0, input: 0 mis-ordered: 0 (0 bytes)
Event Timers (current time is 0x1429F084):
Timer Starts Wakeups Next
Retrans 2971 77 0x0
TimeWait 0 0 0x0
AckHold 2894 1503 0x0
SendWnd 0 0 0x0
KeepAlive 0 0 0x0
GiveUp 0 0 0x0
PmtuAger 0 0 0x0
DeadWait 0 0 0x0
iss: 803218558 snduna: 803273755 sndnxt: 803273755 sndwnd: 16289
irs: 4123967590 rcvnxt: 4124022787 rcvwnd: 16289 delrcvwnd: 95
SRTT: 300 ms, RTTO: 303 ms, RTV: 3 ms, KRTT: 0 ms
minRTT: 32 ms, maxRTT: 408 ms, ACK hold: 200 ms
Flags: passive open, nagle, gen tcbs
Datagrams (max data segment is 536 bytes):
Rcvd: 4531 (out of order: 0), with data: 2895, total data bytes: 55215
Sent: 4577 (retransmit: 77, fastretransmit: 0), with data: 2894, total data
bytes: 55215
The table below describes the significant fields shown in the display.
Field |
Description |
---|---|
BGP neighbor |
IP address of the BGP neighbor and its autonomous system number. If the neighbor is in the same autonomous system as the router, then the link between them is internal; otherwise, it is considered external. |
remote AS |
Autonomous system of the neighbor. |
internal link |
Indicates that this peer is an interior Border Gateway Protocol (iBGP) peer. |
BGP version |
BGP version being used to communicate with the remote router; the router ID (an IP address) of the neighbor is also specified. |
remote router ID |
A 32-bit number written as 4 octets separated by periods (dotted-decimal format). |
BGP state |
Internal state of this BGP connection. |
up for |
Amount of time that the underlying TCP connection has been in existence. |
Last read |
Time that BGP last read a message from this neighbor. |
hold time |
Maximum amount of time that can elapse between messages from the peer. |
keepalive interval |
Time period between sending keepalive packets, which help ensure that the TCP connection is up. |
Neighbor capabilities |
BGP capabilities advertised and received from this neighbor. |
Route refresh |
Indicates that the neighbor supports dynamic soft reset using the route refresh capability. |
Address family IPv6 Unicast |
Indicates that BGP peers are exchanging IPv6 reachability information. |
ipv6 MPLS Label capability |
Indicates that MPLS labels are being assigned to IPv6 address prefixes. |
Received |
Number of total BGP messages received from this peer, including keepalives. |
notifications |
Number of error messages received from the peer. |
Sent |
Total number of BGP messages that have been sent to this peer, including keepalives. |
notifications |
Number of error messages the router has sent to this peer. |
advertisement runs |
Value of the minimum advertisement interval. |
For address family |
Address family to which the following fields refer. |
BGP table version |
Indicates that the neighbor has been updated with this version of the primary BGP routing table. |
neighbor version |
Number used by the software to track the prefixes that have been sent and those that must be sent to this neighbor. |
Route refresh request |
Number of route refresh requests sent and received from this neighbor. |
Community attribute (not shown in sample output) |
Appears if the neighbor send-community command is configured for this neighbor. |
Inbound path policy (not shown in sample output) |
Indicates whether an inbound filter list or route map is configured. |
Outbound path policy (not shown in sample output) |
Indicates whether an outbound filter list, route map, or unsuppress map is configured. |
bgp-in (not shown in sample output) |
Name of the inbound update prefix filter list for the IPv6 unicast address family. |
aggregate (not shown in sample output) |
Name of the outbound update prefix filter list for the IPv6 unicast address family. |
uni-out (not shown in sample output) |
Name of the outbound route map for the IPv6 unicast address family. |
accepted prefixes |
Number of prefixes accepted. |
Prefix advertised |
Number of prefixes advertised. |
suppressed |
Number of prefixes suppressed. |
withdrawn |
Number of prefixes withdrawn. |
history paths (not shown in sample output) |
Number of path entries held to remember history. |
Connections established |
Number of times the router has established a TCP connection and the two peers have agreed to speak BGP with each other. |
dropped |
Number of times that a good connection has failed or been taken down. |
Last reset |
Elapsed time (in hours:minutes:seconds) since this peering session was last reset. |
Connection state |
State of the BGP peer. |
unread input bytes |
Number of bytes of packets still to be processed. |
Local host, Local port |
Peering address of the local router, plus the port. |
Foreign host, Foreign port |
Peering address of the neighbor. |
Event Timers |
Table that displays the number of starts and wakeups for each timer. |
iss |
Initial send sequence number. |
snduna |
Last send sequence number for which the local host sent but has not received an acknowledgment. |
sndnxt |
Sequence number the local host will send next. |
sndwnd |
TCP window size of the remote host. |
irs |
Initial receive sequence number. |
rcvnxt |
Last receive sequence number the local host has acknowledged. |
rcvwnd |
TCP window size of the local host. |
delrecvwnd |
Delayed receive window--data the local host has read from the connection, but has not yet subtracted from the receive window the host has advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is applied to the rcvwnd field. |
SRTT |
A calculated smoothed round-trip timeout (in milliseconds). |
RTTO |
Round-trip timeout (in milliseconds). |
RTV |
Variance of the round-trip time (in milliseconds). |
KRTT |
New round-trip timeout (in milliseconds) using the Karn algorithm. This field separately tracks the round-trip time of packets that have been re-sent. |
minRTT |
Smallest recorded round-trip timeout (in milliseconds) with hard wire value used for calculation. |
maxRTT |
Largest recorded round-trip timeout (in milliseconds). |
ACK hold |
Time (in milliseconds) the local host will delay an acknowledgment in order to "piggyback" data on it. |
Flags |
IP precedence of the BGP packets. |
Datagrams: Rcvd |
Number of update packets received from neighbor. |
with data |
Number of update packets received with data. |
total data bytes |
Total number of bytes of data. |
Sent |
Number of update packets sent. |
with data |
Number of update packets with data sent. |
total data bytes |
Total number of data bytes. |
The following is sample output from the show bgp ipv6 neighbors command with the advertised-routes keyword:
Router# show bgp ipv6 unicast neighbors 3FFE:700:20:1::11 advertised-routes
BGP table version is 21880, local router ID is 192.168.7.225
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 2001:200::/35 3FFE:700:20:1::11 0 293 3425 2500 i
*> 2001:208::/35 3FFE:C00:E:B::2 0 237 7610 i
*> 2001:218::/35 3FFE:C00:E:C::2 0 3748 4697 i
The following is sample output from the show bgp ipv6 neighbors command with the routes keyword:
Router# show bgp ipv6 unicast neighbors 3FFE:700:20:1::11 routes
BGP table version is 21885, local router ID is 192.168.7.225
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 2001:200::/35 3FFE:700:20:1::11 0 293 3425 2500 i
* 2001:208::/35 3FFE:700:20:1::11 0 293 7610 i
* 2001:218::/35 3FFE:700:20:1::11 0 293 3425 4697 i
* 2001:230::/35 3FFE:700:20:1::11 0 293 1275 3748 i
The table below describes the significant fields shown in the display.
Field |
Description |
---|---|
BGP table version |
Internal version number of the table. This number is incremented whenever the table changes. |
local router ID |
A 32-bit number written as 4 octets separated by periods (dotted-decimal format). |
Status codes |
Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values:
|
Origin codes |
Indicates the origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values:
|
Network |
IPv6 address of the network the entry describes. |
Next Hop |
IPv6 address of the next system that is used when forwarding a packet to the destination network. An entry of two colons (::) indicates that the router has some non-BGP routes to this network. |
Metric |
The value of the interautonomous system metric. This field is frequently not used. |
LocPrf |
Local preference value as set with the set local-preference route-map configuration command. The default value is 100. |
Weight |
Weight of the route as set via autonomous system filters. |
Path |
Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path. |
The following is sample output from the show bgp ipv6 neighbors command with the paths keyword:
Router# show bgp ipv6 unicast neighbors 3FFE:700:20:1::11 paths ^293
Address Refcount Metric Path
0x6131D7DC 2 0 293 3425 2500 i
0x6132861C 2 0 293 7610 i
0x6131AD18 2 0 293 3425 4697 i
0x61324084 2 0 293 1275 3748 i
0x61320E0C 1 0 293 3425 2500 2497 i
0x61326928 1 0 293 3425 2513 i
0x61327BC0 2 0 293 i
0x61321758 1 0 293 145 i
0x61320BEC 1 0 293 3425 6509 i
0x6131AAF8 2 0 293 1849 2914 ?
0x61320FE8 1 0 293 1849 1273 209 i
0x613260A8 2 0 293 1849 i
0x6132586C 1 0 293 1849 5539 i
0x6131BBF8 2 0 293 1849 1103 i
0x6132344C 1 0 293 4554 1103 1849 1752 i
0x61324150 2 0 293 1275 559 i
0x6131E5AC 2 0 293 1849 786 i
0x613235E4 1 0 293 1849 1273 i
0x6131D028 1 0 293 4554 5539 8627 i
0x613279E4 1 0 293 1275 3748 4697 3257 i
0x61320328 1 0 293 1849 1273 790 i
0x6131EC0C 2 0 293 1275 5409 i
![]() Note |
The caret (^) symbol in the example is a regular expression that is entered by simultaneously pressing the Shift and 6 keys on your keyboard. A caret (^) symbol at the beginning of a regular expression matches the start of a line. |
The table below describes the significant fields shown in the display.
Field |
Description |
---|---|
Address |
Internal address where the path is stored. |
Refcount |
Number of routes using that path. |
Metric |
The Multi Exit Discriminator (MED) metric for the path. (The name of this metric for BGP versions 2 and 3 is INTER_AS.) |
Path |
The autonomous system path for that route, followed by the origin code for that route. |
The following sample output from the show bgp ipv6 neighbors command shows the dampened routes for IPv6 address 3FFE:700:20:1::11:
Router# show bgp ipv6 unicast neighbors 3FFE:700:20:1::11 dampened-routes
BGP table version is 32084, local router ID is 192.168.7.225
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network From Reuse Path
*d 3FFE:8030::/28 3FFE:700:20:1::11 00:24:20 293 1275 559 8933 i
The following sample output from the show bgp ipv6 neighbors command shows the flap statistics for IPv6 address 3FFE:700:20:1::11:
Router# show bgp ipv6 unicast neighbors 3FFE:700:20:1::11 flap-statistics
BGP table version is 32084, local router ID is 192.168.7.225
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
Network From Flaps Duration Reuse Path
*d 2001:668::/35 3FFE:700:20:1:: 4923 2d12h 00:59:50 293 1849 3257
*d 3FFE::/24 3FFE:700:20:1:: 4799 2d12h 00:59:30 293 1849 5609 4554
*d 3FFE:8030::/28 3FFE:700:20:1:: 95 11:48:24 00:23:20 293 1275 559 8933
The following sample output from the show bgp ipv6 neighbors command shows the received routes for IPv6 address 2000:0:0:4::2:
Router#
show bgp ipv6 unicast neighbors 2000:0:0:4::2 received-routes
BGP table version is 2443, local router ID is 192.168.0.2
Status codes:s suppressed, d damped, h history, * valid, > best, i - internal
Origin codes:i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 2000:0:0:1::/64 2000:0:0:4::2 0 2 1 i
*> 2000:0:0:2::/64 2000:0:0:4::2 0 2 i
*> 2000:0:0:2:1::/80 2000:0:0:4::2 0 2 ?
*> 2000:0:0:3::/64 2000:0:0:4::2 0 2 ?
* 2000:0:0:4::1/64 2000:0:0:4::2 0 2 ?