Configuring Flexible Command Line Interface

This module describes how to configure and use flexible command line interface (CLI) configuration groups.

Flexible CLI Configuration Groups

Flexible command line interface (CLI) configuration groups provide the ability to minimize repetitive configurations by defining a series of configuration statements in a configuration group, and then applying this group to multiple hierarchical levels in the router configuration tree.

Flexible CLI configuration groups utilize regular expressions that are checked for a match at multiple submodes of the configuration tree based on where the group is applied within the hierarchy. If a match is found at a configuration submode, the corresponding configuration defined in the group is inherited within the matched submode.

Flexible CLI configuration groups also provide an auto-inheritance feature. Auto-inheritance means that any change done to a CLI configuration group is automatically applied to the configuration in any matched submodes that have an apply-group at that hierarchical level. This allows you to make a configuration change or addition once, and have it applied automatically in multiple locations, depending on where you have applied the flexible CLI configuration group.

Flexible Configuration Restrictions

Note these restrictions while using flexible configuration groups:

  • Flexible CLI configuration groups are not supported in administration configurations and corresponding apply-groups are not supported in administration configurations.

  • Use of preconfigured interfaces in configuration groups is not supported.

  • Downgrading from an image that supports configuration groups to an image that does not support them is not supported.

  • Access lists, quality of service and route policy configurations do not support the use of configuration groups. Configurations such as these are not valid:
    
    group g-not-supported
     ipv4 access-list ...
     !
     ipv6 access-list ...
     !
     ethernet-service access-list ...
     !
     class-map ...
     !
     policy-map ...
     !
     route-policy ...
     !
    end-group
    
    You can, however, reference such configurations, as shown in this example:
    
    group g-reference-ok
     router bgp 6500
      neighbor 7::7
       remote-as 65000
       bfd fast-detect
       update-source Loopback300
       graceful-restart disable
       address-family ipv6 unicast
           route-policy test1 in
        route-policy test2 out
        soft-reconfiguration inbound always
       !
      !
     !
     interface Bundle-Ether1005
       bandwidth 10000000
       mtu 9188
          service-policy output input_1                                             
       load-interval 30
     !
    end-group
      
  • Some regular expressions are not supported within groups. For example, ‘?’, ‘|’ and ‘$,’ are not supported within groups. Also some characters such as /d and /w are not supported.

    • The choice operator “|” to express multiple match expressions within a regular expression is not supported. For example, these expressions are not supported:

      Gig.*|Gig.*\..*—To match on either Gigabit Ethernet main interfaces or Gigabit Ethernet sub-interfaces.

      Gig.*0/0/0/[1-5]|Gig.*0/0/0/[10-20]—To match on either Gig.*0/0/0/[1-5] or Gig.*0/0/0/[10-20].

      'TenGigE.*|HundredGigE.*—To match on either TenGigE.* or HundredGigE.* .

  • Commands that require a node identifier for the location keyword are not supported. For example, this configuration is not supported:
    lpts pifib hardware police location 0/RP0/CPU0
  • Overlapping regular expressions within a configuration group for the same configuration are not supported. For example:
    
    group G-INTERFACE
    interface 'gig.*a.*'
      mtu 1500
    !
    interface 'gig.*e.* '
      mtu 2000
    !
    end-group
    
    interface gigabitethernet0/0/0/* ---- where * is 0 to 79 or 0 to 39
      apply-group G-INTERFACE
      
    This configuration is not permitted because it cannot be determined whether the interface GigabitEthernet0/0/0/* configuration inherits mtu 1500 or mtu 2000. Both expressions in the configuration group match GigabitEthernet0/0/0/*.
  • Up to eight configuration groups are permitted on one apply-group command.

Configuring a Configuration Group

A configuration group includes a series of configuration statements that can be used in multiple hierarchical levels in the router configuration tree. By using regular expressions in a configuration group, you can create generic commands that can be applied in multiple instances.

Use this task to create and use a configuration group.


Note

Flexible CLI configurations are not available through the XML interface.


SUMMARY STEPS

  1. configure
  2. group group-name
  3. Enter configuration commands, starting from global configuration mode. Use regular expressions for interface names and other variable instances.
  4. end-group
  5. apply-group

DETAILED STEPS


Step 1

configure

Example:


RP/0/RP0/CPU0:router# configure

Enters mode.

Step 2

group group-name

Example:

RP/0/RP0/CPU0:router(config)# group g-interf

Specifies a name for a configuration group and enters group configuration mode to define the group.The group-name argument can have up to 32 characters and cannot contain any special characters.

Step 3

Enter configuration commands, starting from global configuration mode. Use regular expressions for interface names and other variable instances.

Example:


RP/0/RP0/CPU0:router(config)# group g-interf
RP/0/RP0/CPU0:router(config-GRP)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-if)# mtu 1500
  

Specifies the configuration statements that you want included in this configuration group.

For more information regarding the use of regular expressions, see Configuration Group Inheritance with Regular Expressions: Example. This example is applicable to all Gigabit Ethernet interfaces.

Step 4

end-group

Example:

RP/0/RP0/CPU0:router(config-GRP-if)# end-group

Completes the configuration of a configuration group and exits to global configuration mode.

Step 5

apply-group

Example:


RP/0/RP0/CPU0:router(config)# interface GigabitEthernet0/2/0/0
RP/0/RP0/CPU0:router(config-if)# apply-group g-interf
  

Adds the configuration of the configuration group into the router configuration applicable at the location that the group is applied. Groups can be applied in multiple locations, and their effect depends on the location and context.

The MTU value from the group g-interf is applied to the interface GigabitEthernet0/2/0/0. If this group is applied in global configuration mode, the MTU value is inherited by all Gigabit Ethernet interfaces that do not have an MTU value configured.


Simple Configuration Group: Example

This example shows how to use configuration groups to add a global configuration to the system:


RP/0/RP0/CPU0:router(config)# group g-logging
RP/0/RP0/CPU0:router(config-GRP)# logging trap notifications
RP/0/RP0/CPU0:router(config-GRP)# logging console debugging
RP/0/RP0/CPU0:router(config-GRP)# logging monitor debugging
RP/0/RP0/CPU0:router(config-GRP)# logging buffered 10000000
RP/0/RP0/CPU0:router(config-GRP)# end-group

RP/0/RP0/CPU0:router(config)# apply-group g-logging
  

When this configuration is committed, all commands contained in the g-logging configuration group are committed.

Configuration Group Applied to Different Places: Example

Configuration groups can be applied to different places, and their effect depends on the context within which they are applied. Consider this configuration group:


RP/0/RP0/CPU0:router(config)# group g-interfaces
RP/0/RP0/CPU0:router(config-GRP)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-if)# mtu 1500
RP/0/RP0/CPU0:router(config-GRP-if)# exit
RP/0/RP0/CPU0:router(config-GRP)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-if)# mtu 1000
RP/0/RP0/CPU0:router(config-GRP-if)# exit
RP/0/RP0/CPU0:router(config-GRP)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-if)# mtu 2000
RP/0/RP0/CPU0:router(config-GRP-if)# end-group
  
This group can be applied to Gigabit Ethernet interface and in each instance the applicable MTU is applied. For instance, in this example, the Gigabit Ethernet interface is configured to have an MTU of 1000:

RP/0/RP0/CPU0:router(config)# interface GigabitEthernet0/2/0/0
RP/0/RP0/CPU0:router(config-if)# apply-group g-interfaces
RP/0/RP0/CPU0:router(config-if)# ipv4 address 2.2.2.2 255.255.255.0
  

In this example, the Gigabit Ethernet interface is configured to have an MTU of 1500:


RP/0/RP0/CPU0:router(config)# interface GigabitEthernet0/2/0/0
RP/0/RP0/CPU0:router(config-if)# apply-group g-interfaces
RP/0/RP0/CPU0:router(config-if)# ipv4 address 3.3.3.3 255.255.255.0
  

The same configuration group is used in both cases, but only the applicable configuration statements are used.

Verifying the Configuration of Configuration Groups

Use this task to verify the router configuration using configuration groups:

SUMMARY STEPS

  1. show running-config group [group-name]
  2. show running-config
  3. show running-config inheritance
  4. show running-config interface x/y/z inheritance detail

DETAILED STEPS

  Command or Action Purpose
Step 1

show running-config group [group-name]

Example:


RP/0/RP0/CPU0:router# show running-config group
 
group g-int-ge
 interface 'GigabitEthernet.*'
  mtu 1000
  negotiation auto
 !
end-group
 

Displays the contents of a specific or all configured configuration groups.

Step 2

show running-config

Example:


RP/0/RP0/CPU0:router# show running-config

group G-INTERFACE-MTU
 interface ‘GigabitEthernet.*’
  mtu 1500
 !
end-group

interface interface GigabitEthernet0/4/1/0 
 apply-group G-INTERFACE-MTU
!
interface interface GigabitEthernet0/4/1/1 
 apply-group G-INTERFACE-MTU
 mtu 2000
!
  

Displays the running configuration. Any applied groups are displayed. There is no indication as to whether these configuration groups affect the actual configuration or not. In this example, although the group G-INTERFACE-MTU is applied to interface GigabitEthernet0/4/1/1, the configured MTU value is 2000 and not 1500. This happens if the command mtu 2000 is configured directly on the interface. An actual configuration overrides a configuration group configuration if they are the same.

Step 3

show running-config inheritance

Example:


RP/0/RP0/CPU0:router# show running-config inheritance
.
.
group G-INTERFACE-MTU
 interface ‘GigabitEthernet.*’
  mtu 1500
 !
end-group
.
.
interface interface GigabitEthernet0/4/1/0 
 ## Inherited from group G-INTERFACE-MTU
 mtu 1500
!
interface interface GigabitEthernet0/4/1/1
 mtu 2000
!
.
.

Displays the inherited configuration where ever a configuration group has been applied.

Step 4

show running-config interface x/y/z inheritance detail

Example:


RP/0/RP0/CPU0:router# show running-config interface interface GigabitEthernet0/4/1/0 inheritance detail

interface interface GigabitEthernet0/4/1/0 
 ## Inherited from group G-INTERFACE-MTU
 mtu 1500
  

Displays the inherited configuration for a specific configuration command.

Regular Expressions in Configuration Groups

Regular expressions are used in configuration groups to make them widely applicable. Portable Operating System Interface for UNIX (POSIX) 1003.2 regular expressions are supported in the names of configuration statements. Single quotes must be used to delimit a regular expression.


Note

Not all POSIX regular expressions are supported.


Regular Expressions for Interface Identifiers

Configuration groups do not accept exact interface identifiers. You must use a regular expression to identify a group of interfaces that are applicable to the configuration group. The regular expression ‘.*’ is not allowed. You must begin the regular expression for an interface identifier with an unambiguous word, followed by the regular expression. For example, to configure Gigabit Ethernet interfaces, use the regular expression 'GigabitEthernet.*'.

To display a list of available interface types for your router configuration, enter interface ? at the configuration group prompt:


RP/0/RP0/CPU0:router(config-GRP)# interface ?

  ATM              'RegExp': ATM Network Interface(s)
  BVI              'RegExp': Bridge-Group Virtual Interface
  Bundle-Ether     'RegExp': Aggregated Ethernet interface(s)
  GigabitEthernet  'RegExp': GigabitEthernet/IEEE 802.3 interface(s)
  IMA              'RegExp': ATM Network Interface(s)
  Loopback         'RegExp': Loopback interface(s)
  MgmtEth          'RegExp': Ethernet/IEEE 802.3 interface(s)
  Multilink        'RegExp': Multilink network interface(s)
  Null             'RegExp': Null interface
  PW-Ether         'RegExp': PWHE Ethernet Interface
  PW-IW            'RegExp': PWHE VC11 IP Interworking Interface
  Serial           'RegExp': Serial network interface(s)
  tunnel-ip        'RegExp': GRE/IPinIP Tunnel Interface(s)
  tunnel-mte       'RegExp': MPLS Traffic Engineering P2MP Tunnel interface(s)
  tunnel-te        'RegExp': MPLS Traffic Engineering Tunnel interface(s)
  tunnel-tp        'RegExp': MPLS Transport Protocol Tunnel interface
  

Note

Although you are required to enter only enough characters for the interface type to be unique, it is recommended that you enter the entire phrase. All interface types used in regular expressions are case-sensitive.


To specify a subinterface, prefix the expression with the characters \. (backslash period). For example, use interface 'GigabitEthernet.*\..*' to configure all Gigabit Ethernet subinterfaces.

You can specify Layer 2 transport interfaces or point-to-point interfaces as shown in these examples:

group g-l2t
  interface 'Gi.*\..*' l2transport 
.
.
end-group
group g-ptp
  interface 'Gi.*\..*' point-to-point 
.
.
end-group
  

Regular Expressions for an OSPF Configuration

Exact router process names and OSPF areas cannot be used. You must use a regular expression to specify a process name or group of OSPF areas. To specify that the OSFP area can be either a scalar value or an IP address, use the regular expression ‘.*’, as in this example:

group g-ospf
router ospf '.*' 
area '.*'
mtu-ignore enable
!
!
end-group
  
To specify that the OSPF area must be an IP address, use the expression '\.' as in this example:

group g-ospf-ipaddress
router ospf '.*\..*\..*\..*'
area '.*'
passive enable 
!
!
 end-group
  
To specify that the OSPF area must be a scalar value, use the expression '1.*', as in this example:

group g-ospf-match-number
router ospf '.*'
area '1.*'
passive enable
!
!
end-group
  

Regular Expressions for a BGP AS

Exact BGP AS values cannot be used in configuration groups. Use a regular expression to specify either AS plain format, or AS dot format as in the format X.Y. To match AS plain format instances, use a simple regular expression. To match AS dot format instances, use two regular expressions separated by a dot, as shown in this example:


group g-bgp
router bgp '*'.'*' 
address-family ipv4 unicast
!
!
end-group 
  

Regular Expressions for ANCP

Exact Access Node Control Protocol (ANCP) sender-name identifiers cannot be used in configuration groups. Because the sender name argument can be either an IP address or a MAC address, you must specify in the regular expression which one is being used. Specify an IP address as '.*\..*\..*\..*'; specify a MAC address as '.*\..*\..*'.

Resolving to a Uniform Type

Regular expressions must resolve to a uniform type. This is an example of an illegal regular expression:


group g-invalid
 interface ‘.*’
  bundle port-priority 10
 !
interface ‘.*Ethernet.*’
  bundle port-priority 10
 !
end-group
  

In this example, the bundle command is supported for interface type GigabitEthernet but not for interface type ‘FastEthernet’. The regular expressions ‘.*’ and ‘.*Ethernet.*’ match both GigabitEthernet and FastEthernet types. Because the bundle command is not applicable to both these interface types, they do not resolve to a uniform type and therefore the system does not allow this configuration.


Note

If the system cannot determine from the regular expression what the configuration should be, the expression is not considered valid.



Note

The regular expression ‘.*’ is not allowed when referring to an interface identifier. You must begin the regular expression for an interface identifier with an unambiguous word, followed by the regular expression. Refer to Regular Expressions for Interface Identifiers in this section for more information.


Overlapping Regular Expressions

Regular expressions are used in names of configuration statements within a configuration group. This permits inheritance by the configuration when applied to matching names. Single quotes are used to delimit the regular expression. Overlapping regular expression within a configuration group for the same configuration is permitted.

The example, given below, illustrates the process of creating and applying multiple configuration groups:



RP/0//CPU0:router(config)#group FB_flexi_snmp
RP/0//CPU0:router(config-GRP)# snmp-server vrf '.*'
RP/0//CPU0:router(config-GRP-snmp-vrf)# host 1.1.1.1 traps version 2c group_1
RP/0//CPU0:router(config-GRP-snmp-vrf)# host 1.1.1.1 informs version 2c group_1     
RP/0//CPU0:router(config-GRP-snmp-vrf)# context group_1                                                  
RP/0//CPU0:router(config-GRP-snmp-vrf)#
RP/0//CPU0:router(config-GRP-snmp-vrf)#commit

RP/0//CPU0:router(config-GRP-snmp-vrf)#root
RP/0//CPU0:router(config)#
RP/0//CPU0:router(config)#snmp-server vrf vrf1
RP/0//CPU0:router(config-snmp-vrf)#snmp-server vrf vrf10
RP/0//CPU0:router(config-snmp-vrf)#!
RP/0//CPU0:router(config-snmp-vrf)#snmp-server vrf vrf100
RP/0//CPU0:router(config-snmp-vrf)#
RP/0//CPU0:router(config-snmp-vrf)#commit

RP/0//CPU0:router(config-snmp-vrf)#root
RP/0//CPU0:router(config)#
RP/0//CPU0:router(config)#apply-group FB_flexi_snmp
RP/0//CPU0:router(config)#do sh running-config group
group FB_flexi_snmp
 snmp-server vrf '.*'
  host 1.1.1.1 traps version 2c group_1
  host 1.1.1.1 informs version 2c group_1
  context group_1
 !
end-group
apply-group FB_flexi_snmp
snmp-server vrf vrf1
!
snmp-server vrf vrf10
!
snmp-server vrf vrf100
!
RP/0//CPU0:ios#show running-config inheritance detail 


group FB_flexi_snmp
 snmp-server vrf '.*'
  host 1.1.1.1 traps version 2c group_1
  host 1.1.1.1 informs version 2c group_1
  context group_1
 !
end-group
snmp-server vrf vrf1
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 traps version 2c group_1
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 informs version 2c group_1
 ## Inherited from group FB_flexi_snmp
 context group_1
!
snmp-server vrf vrf10
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 traps version 2c group_1
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 informs version 2c group_1
 ## Inherited from group FB_flexi_snmp
 context group_1
!
snmp-server vrf vrf100
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 traps version 2c group_1
 ## Inherited from group FB_flexi_snmp
 host 1.1.1.1 informs version 2c group_1
 ## Inherited from group FB_flexi_snmp
 context group_1


The example given below demonstrates the regular expression. In this example snmp-server vrf '.*’ and snmp-server vrf '[\w]+ are two different regular expressions.


group FB_flexi_snmp
snmp-server vrf '.*’
host 1.1.1.1 traps version 2c group_1
host 1.1.1.1 informs version 2c group_1
context group_1
!
snmp-server vrf '[\w]+’
host 2.2.2.2 traps version 2c group_2
host 2.2.2.2 informs version 2c group_2
context group_2
!
end-group


This individual regular expression gets combined to all the three expressions - snmp-server vrf vrf1, snmp-server vrf vrf10 and snmp-server vrf vrf100 as given below.



apply-group FB_flexi_snmp
snmp-server vrf vrf1
!
snmp-server vrf vrf10
!
snmp-server vrf vrf100
!


In a configuration group, there can be instances of regular expressions overlap. In such cases, the regular expression with the highest priority is activated and inherited, when applied. It has that regular expression, which comes first in the lexicographic order that has the highest priority.

The following example shows how to use overlapping regular expressions and how the expression with higher priority is applied:

 group FB_flexi_snmp                                                                                           
 snmp-server vrf '.*’                                                                                            
  host 1.1.1.1 traps version 2c group_1                                                            
  host 1.1.1.1 informs version 2c group_1                                                        
  context group_1                                                                                                  
 !                                                                                                                                
 snmp-server vrf '[\w]+’                                                                                        
  host 2.2.2.2 traps version 2c group_2
  host 2.2.2.2 informs version 2c group_2
  context group_2
 !
end-group 

The expression shown below has the highest priority:


  
  group FB_flexi_snmp                                                                                           
  snmp-server vrf '.*’                                                                                            
  host 1.1.1.1 traps version 2c group_1                                                            
  host 1.1.1.1 informs version 2c group_1                                                        
  context group_1
                                                                                                
The examples given above, show two different regular expression snmp-server vrf '.*’ and snmp-server vrf '[\w]+'.

The expression below, shows how these two expressions get merged together:



 apply-group FB_flexi_snmp

 snmp-server vrf vrf1
 !
 snmp-server vrf vrf10
 !
 snmp-server vrf vrf100
 !

Any change in a regular expression with lower priority will not affect the inheritance.

Any changes made to an existing regular expression, which is of less (non-top) priority, it will not have any effect on the inheritance.


  snmp-server vrf '[\w]+’                                                                                        
  host 2.2.2.2 traps version 2c group_2
  host 2.2.2.2 informs version 2c group_2
  context group_2

The expression with the higher priority gets inherited, as shown below:


 group FB_flexi_snmp                                                                                           
 snmp-server vrf '.*’                                                                                            
  host 1.1.1.1 traps version 2c group_1                                                            
  host 1.1.1.1 informs version 2c group_1                                                        
  context group_1                                                                                                  

Apply Groups Priority Inheritance

Priority governs inheritance.


Note

From the Cisco IOS XR, Release 6.3.1 onwards, you are able to enter the Flexible CLI config group definition, apply-group and exclude-group command in any order as long as the entire commit has all the group definitions needed.


Apply groups priority inheritance helps flexible configuration groups to handle common configuration statements between groups. When multiple configuration groups have common configuration statements, the inheritance priority is such that the configuration statements present in inner groups have precedence over those configuration statements present in outer groups. In case of tiebreakers, the priority is assigned in accordance to the lexicographical order of regular expressions. User defined order of commands are not accepted.

For example, a configuration statement in configuration group ONE has precedence over another group. A configuration statement in configuration group SEVEN is used only if it does not exist in any other group. Within a configuration group, inheritance priority is the longest match.


   apply-group SIX SEVEN
    router ospf 0
   apply-group FOUR FIVE
    area 0
   apply-group THREE
    interface GigabitEthernet0/0/0/0
   apply-group ONE TWO
      
  !
 !
!
The above example shows two scenarios. The inner most group (apply-group ONE TWO) has the highest priority. Case 1

The first scenario shows which group gets the priority. The example states which group is applied between different configuration groups (different groups with nothing in common). While applying group one (ONE TWO), all the seven groups matches the interface interface GigabitEthernet0/0/0/0- is applied.

Case 2

Here, when all have the same (common) configuration, group one will be active. That is apply-group ONE TWO is active. If group ONE is deleted, then group TWO will be active.

Configuration Examples Using Regular Expressions

Configuration Group with Regular Expression: Example

This example shows the definition of a configuration group for configuring Gigabit Ethernet interfaces with ISIS routing parameters, using regular expressions for the exact interface:


RP/0/RP0/CPU0:router(config)# group g-isis-gige
RP/0/RP0/CPU0:router(config-GRP)# router isis '.*'
RP/0/RP0/CPU0:router(config-GRP-isis)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-isis-if)# lsp-interval 20
RP/0/RP0/CPU0:router(config-GRP-isis-if)# hello-interval 40
RP/0/RP0/CPU0:router(config-GRP-isis-if)# address-family ipv4 unicast
RP/0/RP0/CPU0:router(config-GRP-isis-if-af)# metric 10
RP/0/RP0/CPU0:router(config-GRP-isis-if-af)# end-group
RP/0/RP0/CPU0:router(config)#
  

To illustrate the use of this configuration group, assume that you want to configure these Gigabit Ethernet interfaces with the ISIS routing parameters:


router isis green
 interface GigabitEthernet0/0/0/0
  lsp-interval 20
  hello-interval 40
  address-family ipv4 unicast
   metric 10
  !
 !
 interface GigabitEthernet0/0/0/1
  lsp-interval 20
  hello-interval 40
  address-family ipv4 unicast
   metric 10
  !
 !
 interface GigabitEthernet0/0/0/2
  lsp-interval 20
  hello-interval 40
  address-family ipv4 unicast
   metric 10
  !
 !
 interface GigabitEthernet0/0/0/3
  lsp-interval 20
  hello-interval 40
  address-family ipv4 unicast
   metric 10
  !
 !
!
  
There are three possible ways to use the configuration group to configure these interfaces. The first is by applying the group within the interface configuration, as shown here:

router isis green
 interface GigabitEthernet0/0/0/0
     apply-group g-isis-gige
  !
 !
 interface GigabitEthernet0/0/0/1
     apply-group g-isis-gige
  ! 
 ! 
 interface GigabitEthernet0/0/0/2
     apply-group g-isis-gige
  !
 !
 interface GigabitEthernet0/0/0/3 
     apply-group g-isis-gige
  !
 !
  
In this situation, only the interfaces to which you apply the configuration group inherit the configuration.
The second way to configure these interfaces using the configuration group is to apply the configuration group within the router isis configuration, as shown here:

router isis green
    apply-group g-isis-gige
 interface GigabitEthernet0/0/0/0
 !
 interface GigabitEthernet0/0/0/1
 !
 interface GigabitEthernet0/0/0/2
 !
 interface GigabitEthernet0/0/0/3
 !
!
  
In this way, any other Gigabit Ethernet interfaces that you configure in the ISIS green configuration also inherit these configurations.
The third way to configure these interfaces using the configuration group is to apply the group at the global level as shown here:

   apply-group g-isis-gige
router isis green
 interface GigabitEthernet0/0/0/0
 !
 interface GigabitEthernet0/0/0/1
 !
 interface GigabitEthernet0/0/0/2
 !
 interface GigabitEthernet0/0/0/3
 !
!
  
In this example, the configuration of the group is applied to all Gigabit Ethernet interfaces configured for ISIS.

Configuration Group Inheritance with Regular Expressions: Example

Local Configuration Has Precedence Over Configuration Group

An explicit configuration takes precedence over a configuration applied from a configuration group. For example, assume that this configuration is running on the router:


router ospf 100
 packet-size 1000
!
   

You configure this configuration group, apply it, and commit it to the configuration.


RP/0/RP0/CPU0:router(config)# group g-ospf
RP/0/RP0/CPU0:router(config-GRP)# router ospf '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf)# nsf cisco
RP/0/RP0/CPU0:router(config-GRP-ospf)# packet-size 3000
RP/0/RP0/CPU0:router(config-GRP-ospf)# end-group

RP/0/RP0/CPU0:router(config)# apply-group g-ospf
  

The result is effectively this configuration:


router ospf 100
 packet-size 1000
 nsf cisco
  

Note that packet-size 3000 is not inherited from the configuration group because the explicit local configuration has precedence.

The configuration in the configuration group must match the configuration on the router to be inherited. If the configuration does not match, it is not inherited. For example, assume that this configuration is running on the router:


router ospf 100
 auto-cost disable
!
  

You configure this configuration and commit it to the configuration.


RP/0/RP0/CPU0:router(config)# group g-ospf
RP/0/RP0/CPU0:router(config-GRP)# router ospf '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf)# area '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf-ar)# packet-size 2000
RP/0/RP0/CPU0:router(config-GRP-ospf)# end-group
  
RP/0/RP0/CPU0:router(config)# apply-group g-ospf
  
RP/0/RP0/CPU0:router(config)# router ospf 200
RP/0/RP0/CPU0:router(config-ospf)# area 1
  

The result is effectively this configuration:


router ospf 100
  auto-cost disable

router ospf 200
  area 1
  packet-size 2000 
  

The packet size is inherited by the ospf 200 configuration, but not by the ospf 100 configuration because the area is not configured.

Layer 2 Transport Configuration Group: Example

This example shows how to configure and apply a configuration group with Layer 2 transport subinterfaces:


RP/0/RP0/CPU0:router(config)# group g-l2trans-if
RP/0/RP0/CPU0:router(config-GRP)# interface 'TenGigE.*\..*' l2transport
RP/0/RP0/CPU0:router(config-GRP)# mtu 1514
RP/0/RP0/CPU0:router(config-GRP)# end-group 

RP/0/RP0/CPU0:router(config)# interface TenGigE0/0/0/0.1 l2transport
RP/0/RP0/CPU0:router(config-if)# apply-group g-l2trans-if
   

When this configuration is committed, the Ten Gigabit Ethernet interface 0/0/0/0.1 inherits the 1514 MTU value. This is the output displayed from the show running-config inheritence command for the Ten Gigabit Ethernet interface:



interface TenGigE0/0/0/0.1 l2transport
 ## Inherited from group g-l2trans-if
 mtu 1514
!

Configuration Group Precedence: Example

When similar configuration statements are contained in multiple configuration groups, groups applied in inner configuration modes take precedence over groups applied in outer modes. This example shows two configuration groups that configure different cost values for OSPF.


RP/0/RP0/CPU0:router(config)# group g-ospf2
RP/0/RP0/CPU0:router(config-GRP)# router ospf '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf)# area '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf-ar)# cost 2
RP/0/RP0/CPU0:router(config-GRP-ospf-ar)# end-group

RP/0/RP0/CPU0:router(config)# group g-ospf100
RP/0/RP0/CPU0:router(config-GRP)# router ospf '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf)# area '.*'
RP/0/RP0/CPU0:router(config-GRP-ospf-ar)# cost 100
RP/0/RP0/CPU0:router(config-GRP-ospf-ar)# end-group
  

If these configuration groups are applied as follows, the cost 2 specified in g-ospf2 is inherited by OSPF area 0 because the group is applied in a more inner configuration mode. In this case, the configuration in group g-ospf100 is ignored.


RP/0/RP0/CPU0:router(config)# router ospf 0
RP/0/RP0/CPU0:router(config-ospf)# apply-group g-ospf100
RP/0/RP0/CPU0:router(config-ospf)# area 0
RP/0/RP0/CPU0:router(config-ospf-ar)# apply-group g-ospf2
  

Changes to Configuration Group are Automatically Inherited: Example

When you make changes to a configuration group that is committed and applied to your router configuration, the changes are automatically inherited by the router configuration. For example, assume that this configuration is committed:


group g-interface-mtu
 interface ‘GigabitEthernet.*’
  mtu 1500
 !
end-group

interface POS0/4/1/0 
 apply-group g-interface-mtu
!
  

Now you change the configuration group as in this example:


RP/0/RP0/CPU0:router(config)# group g-interface-mtu
RP/0/RP0/CPU0:router(config-GRP)# interface 'GigabitEthernet.*'
RP/0/RP0/CPU0:router(config-GRP-if)# mtu 2000
RP/0/RP0/CPU0:router(config-GRP-if)# end-group
  

When this configuration group is committed, the MTU configuration for interface GigabitEthernet0/4/1/0 is automatically updated to 2000.

Configuration Examples for Flexible CLI Configuration

Basic Flexible CLI Configuration: Example

This example shows that the Media Access Control (MAC) accounting configuration from the gd21 configuration group is applied to all Gigabit Ethernet interfaces in slot 2, ports 1 to 9.

  1. Configure the configuration group that configures MAC accounting:

    
    RP/0/RP0/CPU0:router# show running group gd21
     
    group gd21
    interface 'GigabitEthernet0/0/0/2[1-9]'
    description general interface inheritance check
    load-interval 30
    mac-accounting ingress
    mac-accounting egress
    !
    end-group
      
  2. Check that the corresponding apply-group is configured in global configuration or somewhere in the hierarchy:
    
    RP/0/RP0/CPU0:router# show running | in apply-group gd21
    
    Building configuration...
    apply-group gd21
      
  3. Check the concise local view of the configuration of some of the interfaces:

    
    RP/0/RP0/CPU0:router# show running interface
    
    interface GigabiEthernet0/0/0/21
    !
    interface GigabitEthernet0/0/0/22
    !
    
  4. Verify that the match and inheritance occur on these interfaces:

    
    RP/0/RP0/CPU0:router# show running-config inheritance interface
    
    interface GigabitEthernet0/0/0/21
    ## Inherited from group gd21
    description general interface inheritance check
    ## Inherited from group gd21
    load-interval 30
    ## Inherited from group gd21
    mac-accounting ingress
    ## Inherited from group gd21
    mac-accounting egress
    !
    Interface GigabitEthernet0/0/0/22
    ## Inherited from group gd21
    description general interface inheritance check
    ## Inherited from group gd21
    load-interval 30
    ## Inherited from group gd21
    mac-accounting ingress
    ## Inherited from group gd21
    mac-accounting egress
    !  
    !
    
  5. Verify that the inherited configuration actually takes effect:

    
    RP/0/RP0/CPU0:router# show mac-accounting GigabitEthernet0/0/0/21
    
    GigabitEthernet0/0/0/21
      Input (96 free)
        6c9c.ed35.90fd:  1271 packets, 98426 bytes
            Total: 1271 packets, 98426 bytes
      Output (96 free)
        6c9c.ed35.90fd:   774 packets, 63265 bytes
            Total: 774 packets, 63264 bytes
      

Interface MTU Settings for Different Interface Types: Example

This example shows that an MTU value is configured on different interface types.

  1. Configure an interface MTU configuration group and apply this group:

    
    RP/0/RP0/CPU0:router# show running group l2tr
    
    group l2tr
    interface 'GigabitEthernet0/0/0/3.*'
    mtu 1500
    !
    interface 'GigabitEthernet0/0/0/9\..*'
    mtu 1400
    !
    interface 'GigabitEthernet0/0/0/9\..*' l2transport
    mtu 1400
    !
    end-group
    
    RP/0/RP0/CPU0:router# show running | inc apply-group
    
    Building configuration...
    
    apply-group l2tr 
      
  2. Check the concise view and the inheritance view of the various interfaces:

    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet0/0/0/30         
    
    interface GigabitEthernet0/0/0/30
    !
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet0/0/0/30  inheritance detail
    
    interface GigabitEthernet0/0/0/30
    ## Inherited from group l2tr
    mtu 1500
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet0/0/0/9.800         
    
    interface GigabitEthernet0/0/0/9.800
      encapsulation dot1q 800
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet0/0/0/9.800 inheritance detail
    
    interface GigabitEthernet0/0/0/9.800
    ## Inherited from group l2tr
    mtu 1400
    encapsulation dot1q800
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet0/0/0/9.250         
    
    interface GigabitEthernet0/0/0/9.250 l2transport
      encapsulation dot1q 250
    !
    
    RP/0/RP0/CPU0:router# show running interface  gigabitEthernet0/0/0/9.800 inheritance detail
    
    interface GigabitEthernet0/0/0/9.250 l2transport
    encapsulation dot1q250
    ## Inherited from group l2tr
    mtu 1400
    !
      
  3. Verify that the correct values from the group do take effect:

    
    RP/0/RP0/CPU0:router# show interface gigabitEthernet 0/0/0/30
    
    GigabitEthernet0/0/0/30 is down, line protocol is down 
      Interface state transitions: 0
      Hardware is GigabitEthernet, address is 0026.9824.ee56 (bia 0026.9824.ee56)
      Internet address is Unknown
      MTU 1500 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
         reliability 255/255, txload 0/255, rxload 0/255
      Encapsulation ARPA,
      Full-duplex, 1000Mb/s, link type is force-up
      output flow control is off, input flow control is off
      loopback not set,
      Last input never, output never
      Last clearing of "show interface" counters never
      5 minute input rate 0 bits/sec, 0 packets/sec
      5 minute output rate 0 bits/sec, 0 packets/sec
         0 packets input, 0 bytes, 0 total input drops
         0 drops for unrecognized upper-level protocol
         Received 0 broadcast packets, 0 multicast packets
                  0 runts, 0 giants, 0 throttles, 0 parity
         0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
         0 packets output, 0 bytes, 0 total output drops
         Output 0 broadcast packets, 0 multicast packets
         0 output errors, 0 underruns, 0 applique, 0 resets
         0 output buffer failures, 0 output buffers swapped out
    
    RP/0/RP0/CPU0:router# show interface gigabitEthernet 0/0/0/9.801
    
    GigabitEthernet0/0/0/9.801 is up, line protocol is up 
      Interface state transitions: 1
      Hardware is VLAN sub-interface(s), address is 0026.9824.ee41
      Internet address is Unknown
      MTU 1400 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
         reliability 255/255, txload 0/255, rxload 0/255
      Encapsulation 802.1Q Virtual LAN, VLAN Id 801,  loopback not set,
      Last input never, output never
      Last clearing of "show interface" counters never
      5 minute input rate 0 bits/sec, 0 packets/sec
      5 minute output rate 0 bits/sec, 0 packets/sec
         0 packets input, 0 bytes, 0 total input drops
         0 drops for unrecognized upper-level protocol
         Received 0 broadcast packets, 0 multicast packets
         0 packets output, 0 bytes, 0 total output drops
         Output 0 broadcast packets, 0 multicast packets
    
    
    RP/0/RP0/CPU0:router# show interface gigabitEthernet 0/0/0/9.250
    
    GigabitEthernet0/0/0/9.250 is up, line protocol is up 
      Interface state transitions: 1
      Hardware is VLAN sub-interface(s), address is 0026.9824.ee41
      Layer 2 Transport Mode
      MTU 1400 bytes, BW 1000000 Kbit (Max: 1000000 Kbit)
         reliability Unknown, txload Unknown, rxload Unknown
      Encapsulation 802.1Q Virtual LAN,
        Outer Match: Dot1Q VLAN 250
        Ethertype Any, MAC Match src any, dest any
      loopback not set,
      Last input never, output never
      Last clearing of "show interface" counters never
         0 packets input, 0 bytes
         0 input drops, 0 queue drops, 0 input errors
         0 packets output, 0 bytes
    
         0 output drops, 0 queue drops, 0 output errors
      

ACL Referencing: Example

This example shows how to reference access-lists on a number of interfaces using configuration groups.

  1. Configure the configuration group and apply-group:

    
    RP/0/RP0/CPU0:router# show running group acref 
    
    group acref
     interface 'GigabitEthernet0/0/0/3.*'
      ipv4 access-group adem ingress
      ipv4 access-group adem egress
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running | inc apply-group 
    
    Building configuration...
    
    apply-group isis l2tr isis2 mpp bundle1 acref
      
  2. Check the concise and inheritance view of the matching configurations:

    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/30
    
    interface GigabitEthernet0/0/0/30
    !
    
    RP/0/RP0/CPU0:router# show running interface GigabitEthernet 0/0/0/30 inheritance detail
    
    interface GigabitEthernet0/0/0/30
     ## Inherited from group l2tr
     mtu 1500
     ## Inherited from group acref
     ipv4 access-group adem ingress
     ## Inherited from group acref
     ipv4 access-group adem egress
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/31
    
    interface GigabitEthernet0/0/0/31
    !
    
    RP/0/RP0/CPU0:router# show running interface GigabitEthernet 0/0/0/31 inheritance detail
    
    interface GigabitEthernet0/0/0/31
     ## Inherited from group l2tr
     mtu 1500
     ## Inherited from group acref
     ipv4 access-group adem ingress
     ## Inherited from group acref
     ipv4 access-group adem egress
      
  3. Check that the ACL group configuration actually got configured by using a traffic generator and watching that denied traffic is dropped.

Local Configuration Takes Precedence: Example

This example illustrates that local configurations take precedence when there is a discrepancy between a local configuration and the configuration inherited from a configuration group.

  1. Configure a local configuration in a configuration submode with an access list:

    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/39
    
    interface GigabitEthernet0/0/0/39
     ipv4 access-group smany ingress
     ipv4 access-group smany egress
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/38
    
    interface GigabitEthernet0/0/0/38
    !
    
    RP/0/RP0/CPU0:router# show running ipv4 access-list smany 
    
    ipv4 access-list smany
     10 permit ipv4 any any
    !
    
    RP/0/RP0/CPU0:router# show running ipv4 access-list adem
    
    ipv4 access-list adem
     10 permit ipv4 21.0.0.0 0.255.255.255 host 55.55.55.55
     20 deny ipv4 any any
    !
    
  2. Configure and apply the access list group configuration:

    
    RP/0/RP0/CPU0:router# show running group acref 
    
    group acref
     interface 'GigabitEthernet0/0/0/3.*'
      ipv4 access-group adem ingress
      ipv4 access-group adem egress
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running | inc apply-group 
    
    Building configuration...
    apply-group isis l2tr isis2 mpp bundle1 acref
      
  3. Check the concise and inheritance views for the matching interface where the access list reference is configured locally:

    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/39
    
    interface GigabitEthernet0/0/0/39
     ipv4 access-group smany ingress
     ipv4 access-group smany egress
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/39 inheritance detail
    
    interface GigabitEthernet0/0/0/39
     ## Inherited from group l2tr
     mtu 1500
     ipv4 access-group smany ingress
     ipv4 access-group smany egress     << no config inherited, local config prioritized
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/38
    
    interface GigabitEthernet0/0/0/38
    !
    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/0/0/38 inheritance detail
    
    interface GigabitEthernet0/0/0/38
     ## Inherited from group l2tr
     mtu 1500
     ## Inherited from group acref
     ipv4 access-group adem ingress
     ## Inherited from group acref
     ipv4 access-group adem egress
    !
     
  4. Use a traffic generator to verify that the traffic pattern for interface GigabitEthernet0/0/0/39 gets acted on by the access list in the local configuration (smany) and not according to the inherited referenced access list (adem).

ISIS Hierarchical Configuration: Example

This example illustrates inheritance and priority handling with two ISIS groups using an ISIS configuration.

  1. Configure the local ISIS configuration:

    
    RP/0/RP0/CPU0:router# show running router isis
    
    router isis vink
     net 49.0011.2222.2222.2222.00
     address-family ipv4 unicast
      mpls traffic-eng level-1-2
      mpls traffic-eng router-id Loopback0
      redistribute connected
     !
     interface Bundle-Ether1
      address-family ipv4 unicast
      !
     !
     interface Bundle-Ether2
     !
     interface Loopback0
     !
     interface TenGigE0/2/0/0.3521
      address-family ipv4 unicast
      !
     !
     interface TenGigE0/2/0/0.3522
      address-family ipv4 unicast
      !
     !
     interface TenGigE0/2/0/0.3523
      address-family ipv4 unicast
      !
     !
     interface TenGigE0/2/0/0.3524
      address-family ipv4 unicast
      !
     !
     interface TenGigE0/2/0/0.3525
      address-family ipv4 unicast
      !
     !
     interface TenGigE0/2/0/0.3526
     !
     interface TenGigE0/2/0/0.3527
     !
     interface TenGigE0/2/0/0.3528
     !
     interface TenGigE0/2/0/1
      address-family ipv4 unicast
      !
     !
    !
      
  2. Configure two ISIS groups and apply these to the configuration:

    
    RP/0/RP0/CPU0:router# show running group isis
    
    group isis
     router isis '.*'
      address-family ipv4 unicast
       mpls traffic-eng level-1-2
       mpls traffic-eng router-id Loopback0
       redistribute connected
       redistribute ospf 1 level-1-2
      !
      interface 'TenGig.*'
       lsp-interval 40
       hello-interval 15
       address-family ipv4 unicast
        metric 50
       !
      !
      interface 'Bundle-Ether.*'
       address-family ipv4 unicast
        metric 55
       !
      !
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running group isis2
    
    group isis2
     router isis '.*'
     !
     router isis '^(vink)'
      address-family ipv4 unicast
      !
      interface '(^Ten)Gig.*'
      !
      interface '^(Ten)Gig.*'
       address-family ipv4 unicast
        metric 66
       !
      !
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running | inc apply-group
     
    Building configuration...
    
    apply-group isis  l2tr  isis2  mpp  bundle1  acref
      
  3. Check the inheritance view of the ISIS configuration:

    
    RP/0/RP0/CPU0:router# show running router isis inheritance detail
    
    router isis vink
     net 49.0011.2222.2222.2222.00
     address-family ipv4 unicast
      mpls traffic-eng level-1-2
      mpls traffic-eng router-id Loopback0
      redistribute connected
      ## Inherited from group isis
      redistribute ospf 1 level-1-2
     !
     interface Bundle-Ether1
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 55
      !
     !
     interface Bundle-Ether2
      ## Inherited from group isis
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 55
      !
     !
     interface Loopback0
     !
     interface TenGigE0/2/0/0.3521
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3522
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3523
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3524
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3525
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3526
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      ## Inherited from group isis
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3527
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      ## Inherited from group isis
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/0.3528
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      ## Inherited from group isis
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
     interface TenGigE0/2/0/1
      ## Inherited from group isis
      lsp-interval 40
      ## Inherited from group isis
      hello-interval 15
      address-family ipv4 unicast
       ## Inherited from group isis
       metric 50
      !
     !
    !
    
  4. Verify the actual functionality:

    
    RP/0/RP0/CPU0:router# show isis interface TenGigE0/2/0/0.3528 | inc Metric
    
    Metric (L1/L2):         50/50
      

OSPF Hierarchy: Example

This example illustrates hierarchical inheritance and priority. The configuration that is lower in hierarchy gets the highest priority.

  1. Configure a local OSPF configuration:

    
    RP/0/RP0/CPU0:router# show running router ospf 
    
    router ospf 1
     apply-group go-c
     nsr
     router-id 121.121.121.121
     nsf cisco
     redistribute connected
     address-family ipv4 unicast
     area 0
      apply-group go-b
      interface GigabitEthernet0/0/0/0
       apply-group go-a
      !
      interface GigabitEthernet0/0/0/1
      !
      interface GigabitEthernet0/0/0/3
      !
      interface GigabitEthernet0/0/0/4
      !
      interface GigabitEthernet0/0/0/21
       bfd minimum-interval 100
       bfd fast-detect
       bfd multiplier 3
      !
      interface TenGigE0/2/0/0.3891
      !
      interface TenGigE0/2/0/0.3892
      !
      interface TenGigE0/2/0/0.3893
      !
      interface TenGigE0/2/0/0.3894
      !
     !
    !
    router ospf 100
    !
    router ospf 1000
    !
    router ospf 1001
    !
    
  2. Configure a configuration group and apply it in a configuration submode:

    
    RP/0/RP0/CPU0:router# show running group go-a
    
    group go-a
     router ospf '.*'
      area '.*'
       interface 'Gig.*'
        cost 200
       !
      !
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running group go-b
    
    group go-b
     router ospf '.*'
      area '.*'
       interface 'Gig.*'
        cost 250
       !
      !
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running group go-c
    
    group go-c
     router ospf '.*'
      area '.*'
       interface 'Gig.*'
        cost 300
       !
      !
     !
    
    end-group
  3. Check the inheritance view and verify that the apply-group in the lowest configuration submode gets the highest priority:

    
    RP/0/RP0/CPU0:router# show running router ospf 1 inheritance detail
     
    router ospf 1
     nsr
     router-id 121.121.121.121
     nsf cisco
     redistribute connected
     address-family ipv4 unicast
     area 0
      interface GigabitEthernet0/0/0/0
       ## Inherited from group go-a
       cost 200                     << apply-group in lowest submode  gets highest priority
      !
      interface GigabitEthernet0/0/0/1
       ## Inherited from group go-b
       cost 250     
      !
      interface GigabitEthernet0/0/0/3
       ## Inherited from group go-b
       cost 250
      !
      interface GigabitEthernet0/0/0/4
       ## Inherited from group go-b
       cost 250
      !
      interface GigabitEthernet0/0/0/21
       bfd minimum-interval 100
       bfd fast-detect
       bfd multiplier 3
       ## Inherited from group go-b
       cost 250
      !
      interface TenGigE0/2/0/0.3891
      !
      interface TenGigE0/2/0/0.3892
      !
      interface TenGigE0/2/0/0.3893
      !
      interface TenGigE0/2/0/0.3894
      !
     !
    !
    
  4. Check the functionality of the cost inheritance through the groups:

    
    RP/0/RP0/CPU0:router# show ospf 1 interface GigabitEthernet 0/0/0/0  
    
    GigabitEthernet0/0/0/0 is up, line protocol is up 
      Internet Address 1.0.1.1/30, Area 0 
      Process ID 1, Router ID 121.121.121.121, Network Type BROADCAST, Cost: 200
      Transmit Delay is 1 sec, State DR, Priority 1, MTU 1500, MaxPktSz 1500
      Designated Router (ID) 121.121.121.121, Interface address 1.0.1.1
      No backup designated router on this network
      Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
      Non-Stop Forwarding (NSF) enabled
        Hello due in 00:00:02
      Index 5/5, flood queue length 0
      Next 0(0)/0(0)
      Last flood scan length is 1, maximum is 40
      Last flood scan time is 0 msec, maximum is 7 msec
      LS Ack List: current length 0, high water mark 0
      Neighbor Count is 1, Adjacent neighbor count is 0
      Suppress hello for 0 neighbor(s)
      Multi-area interface Count is 0
      

Link Bundling Usage: Example

This example shows how to configure interface membership in a bundle link:

  1. Configure the configuration groups:

    
    RP/0/RP0/CPU0:router# show running group bundle1
    
    group bundle1
     interface 'GigabitEthernet0/1/0/1[1-6]'
      bundle id 1 mode active
     !
    end-group
    
    RP/0/RP0/CPU0:router# show running | inc apply-group 
    
    Building configuration...
    
    apply-group isis l2tr  isis2  mpp  bundle1
      
  2. Check the local configuration:

    
    RP/0/RP0/CPU0:router# show running interface gigabitEthernet 0/1/0/11
    
    interface GigabitEthernet0/1/0/11
    !
    
    RP/0/RP0/CPU0:router# show running interface Bundle-Ether1
    
    interface Bundle-Ether1
     ipv4 address 108.108.1.1 255.255.255.0
     bundle maximum-active links 10
     bundle minimum-active links 5
    !
      
  3. Check the inheritance configuration view:

    
    RP/0/RP0/CPU0:router# show running interface GigabitEthernet 0/1/0/11  inheritance detail
    
    interface GigabitEthernet0/1/0/11
     ## Inherited from group bundle1
     bundle id 1 mode active
    !
    
  4. Check that the inheritance configuration took effect:

    
    RP/0/RP0/CPU0:router# show interface Bundle-Ether1 
    
    Bundle-Ether1 is up, line protocol is up 
      Interface state transitions: 1
      Hardware is Aggregated Ethernet interface(s), address is 0024.f71f.4bc3
      Internet address is 108.108.1.1/24
      MTU 1514 bytes, BW 6000000 Kbit (Max: 6000000 Kbit)
         reliability 255/255, txload 0/255, rxload 0/255
      Encapsulation ARPA,
      Full-duplex, 6000Mb/s
      loopback not set,
      ARP type ARPA, ARP timeout 04:00:00
        No. of members in this bundle: 6
          GigabitEthernet0/1/0/11      Full-duplex  1000Mb/s     Active          
          GigabitEthernet0/1/0/12      Full-duplex  1000Mb/s     Active          
          GigabitEthernet0/1/0/13      Full-duplex  1000Mb/s     Active          
          GigabitEthernet0/1/0/14      Full-duplex  1000Mb/s     Active          
          GigabitEthernet0/1/0/15      Full-duplex  1000Mb/s     Active          
          GigabitEthernet0/1/0/16      Full-duplex  1000Mb/s     Active          
      Last input 00:00:00, output 00:00:00
      Last clearing of "show interface" counters never
      5 minute input rate 8000 bits/sec, 1 packets/sec
      5 minute output rate 3000 bits/sec, 1 packets/sec
         2058 packets input, 1999803 bytes, 426 total input drops
         0 drops for unrecognized upper-level protocol
         Received 1 broadcast packets, 2057 multicast packets
                  0 runts, 0 giants, 0 throttles, 0 parity
         0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
         1204 packets output, 717972 bytes, 0 total output drops
         Output 2 broadcast packets, 1202 multicast packets
         0 output errors, 0 underruns, 0 applique, 0 resets
         0 output buffer failures, 0 output buffers swapped out
         0 carrier transitions