On Cisco IOS-XR, which BGP configuration group allows you to define address-family independent commands and address-family dependent commands for each address family?

On Cisco IOS-XR, which BGP configuration group allows you to define address-family independent commands and address-family dependent commands for each address family?
A . neighbor-group 
B . session-group 
C . af-group
D . peer-group

View Answer

Answer: A

Explanation:

– Commands relating to a peer group found in Cisco IOS Release 12.2 have been removed from Cisco IOS XRsoftware. Instead, the af-group, session-group, and neighbor-group configuration commands are added tosupport the neighbor in Cisco IOS XR software:

– The af-group command is used to group address family-specific neighbor commands within an IPv4 or IPv6address family. Neighbors that have the same address family configuration are able to use the address familygroup name for their address family-specific configuration. A neighbor inherits the configuration from anaddress family group by way of the use command. If a neighbor is configured to use an address family group,the neighbor will (by default) inherit the entire configuration from the address family group. However, aneighbor will not inherit all of the configuration from the address family group if items are explicitly configuredfor the neighbor.

– The session-group command allows you to create a session group from which neighbors can inherit addressfamily-independent configuration. A neighbor inherits the configuration from a session group by way of the usecommand. If a neighbor is configured to use a session group, the neighbor (by default) inherits the sessiongroup’s entire configuration. A neighbor does not inherit all the configuration from a session group if aconfiguration is done directly on that neighbor.

– The neighbor-group command helps you apply the same configuration to one or more neighbors. Neighborgroups can include session groups and address family groups. This additional flexibility can create a completeconfiguration for a neighbor. Once a neighbor group is configured, each neighbor can inherit the configurationthrough the use command. If a neighbor is configured to use a neighbor group, the neighbor (by default)inherits the neighbor group’s entire BGP configuration.

– However, a neighbor will not inherit all of the configuration from the neighbor group if items are explicitlyconfigured for the neighbor. In addition, some part of the neighbor group’s configuration could be hidden if asession group or address family group was also being used