table-map problem !!!!!

[Anand Solgama]

What is table-map how to use it I tried but failed ...I used it instead route-map but failed !!!!!!!     

[SANTHOSHKUMAR SARAVANAN]

Hi 

Where you are using table-map ?? on BGP

Table-map is that it's a set of rules and regulations that will apply to ALL peers.  Whereas a route-map is on a per-peer basis.   So you have different, or overlay logic to play with!

The things we see otherwise, like in QPPB implementations is that you trigger these things (changing IP Prec or DSCP values, or assigning QOS-groups) in a packet process not a routing process. 

HTH

Sandy

[Anand Solgama]

Thanks I just want to use instead of route-map yes in BGP :) ......so where to use it ?????can we use it instead of route-map anywhere????pls mention again......!!!!!

[sumit19851 · Accepted solution]

Hi,

I checked little on this and dont think that table-map can be used in place of route-map. route-map is used to change attributes of BGP prefixes or filter prefixes while receving/advertising to particular bgp peer.

while table-map is used to filter,modify route (to set traffic-index, qos value) while importing BGP routes into routing table.

So route-map is applicable while BGP routes are getting imported from bgp-in to bgp-local and table-map is used when BGP prefixes are imported from bgp-local to rib-local.

Use of table-map

1. Table-map is configured under router bgp <process> and can be used as filter for BGP prefixes to RIB table.

Benefits of Selective Route Download
-------------------------------------
The BGP—Selective Route Download feature allows a network administrator to selectively download some or none of the BGP routes into the Routing Information Base (RIB). 

The primary application for this feature is to suppress the unnecessary downloading of certain BGP routes to the RIB or Forwarding Information Base (FIB) on a 

dedicated route reflector, which propagates BGP updates without carrying transit traffic. The feature thereby helps to maximize resources available and to improve 

routing scalability and convergence on the dedicated route reflector.

Example:

route-map bgp-to-rib deny 10
!
router bgp 65000
 address-family ipv6 unicast
 table-map bgp-to-rib filter

2. Table-map is also used for BGP policy-accounting feature to set traffic-index

BGP policy-accounting
The Border Gateway Protocol (BGP) policy accounting (PA) feature allows you to account for IP traffic differentially by assigning counters based on community list, AS 

number, and/or AS_PATH on a per input interface basis.

- Define a route-map to match community lists and set appropriate bucket numbers.
- Use the table-map command under BGP to modify the bucket number when the IP routing table is updated with routes learned from BGP.
- Enable the policy accounting feature on the input interface connected to the customer.

3. Tablemap is also used for QPPB (Qos Policy Propagation via BGP)

- Define a route-map to match community lists and do qos marking.
- Use the table-map command under BGP to add thw QOS information when the IP routing table is updated with routes learned from BGP.
- Enable the QPPB on particular interface.

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[VaibhavBhosle]

Hello All,

Can somebody suggest that to modify an AD value of a particular route should I use a route-map or table-map ?