Applying Table Maps

You can use the table-map command on a per-address-family basis to apply a route map to modify IP attributes of BGP routes that are about to be added to the IP routing table. In these route maps, you can use only the set clauses in Table 19.

Table 19: Set Clauses Supported in Route Maps Applied with the Table-Map Command

set distance

• Use to set the administrative distance attribute on routes being installed into the routing table that match the route map.
• Distance is used to establish preference between routes to the same prefix to identify the best route to that prefix. Setting distance in any other circumstance has no effect.
• Example

  host1(config-route-map)#set distance 5

• Use the no version to delete the set clause from a route map.
• See set distance.

set level

• Use to specify where to import routes when all of a route map’s match criteria are met.
• Example

  host1(config-route-map)#set level level-2

• Use the no version to delete the set clause from a route map.
• See set level.

set route-type

• Use to set the routes of the specified type.
• Example

  host1(config-route-map)#set route-type internal

• Use the no version to delete the set clause from a route map.
• See set route-type.

table-map

• Use to apply a policy to BGP routes about to be added to the IP routing table.
• The route map can include any of the clauses listed in Table 19.
• The new route map is applied to all routes that are subsequently placed in the IP routing table. To apply the new table map to routes that are already present in the IP routing table, you must refresh the IP routing table with the clear ip routes * command or the clear ip bgp * command (this command will bounce the BGP sessions).
• Example

  host1(config-router)#table-map distmet1

  host1(config-router)#exit

  host1(config)#exit

  host1#clear ip routes *

• Use the no version to halt application of the route map.
• See table-map.

For example, suppose you want to change the distance and metric attributes to particular values for routes advertised by a members of a particular community. The show ip route bgp command indicates that the routes currently in the table have a variety of values for these attributes:

host1#show ip route bgp 
Protocol/Route type codes:
  I1- ISIS level 1, I2- ISIS level2,
  I- route type intra, IA- route type inter, E- route type external,
  i- metric type internal, e- metric type external,
  O- OSPF, E1- external type 1, E2- external type2,
  N1- NSSA external type1, N2- NSSA external type2

  Prefix/Length     Type      Next Hop        Dist/Met        Intf        
------------------ ------- --------------- -------------- ------------
10.100.3.3/32        Bgp     10.12.12.1       20/0           ATM5/1.12         
10.63.42.23/32      Bgp     10.45.2.31       12/5          ATM5/1.14 

The following commands demonstrate how you can apply the policy to change these values:

The show ip route bgp command reveals the new values:

host1#show ip route bgp 
Protocol/Route type codes:
  I1- ISIS level 1, I2- ISIS level2,
  I- route type intra, IA- route type inter, E- route type external,
  i- metric type internal, e- metric type external,
  O- OSPF, E1- external type 1, E2- external type2,
  N1- NSSA external type1, N2- NSSA external type2

  Prefix/Length     Type      Next Hop        Dist/Met        Intf        
------------------ ------- --------------- -------------- ------------
10.100.3.3/32        Bgp     10.12.12.1       33/44           ATM5/1.12         
10.63.42.23/32      Bgp     10.45.2.31      33/44          ATM5/1.14 

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