Precedence; Configuration Overview - Lenovo RackSwitch G8264 Application Manual

Precedence

Configuration Overview

1. Define a network filter.
2. (Optional) Define the criteria for the access list and enable it.
3. (Optional) Configure the AS filter attributes.
4. Set up the BGP attributes.
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G8264 Application Guide for ENOS 8.4
You can set a priority to a route map by specifying a precedence value with the
following command (Route Map mode):
RS G8264(config)# route­map <map number>(Select a route map)
RS G8264(config­route­map)# precedence
RS G8264(config­route­map)# exit
The smaller the value the higher the precedence. If two route maps have the same
precedence value, the smaller number has higher precedence.
To configure route maps, you need to do the following:
RS G8264(config)# ip match­address 1 <IPv4 address> <IPv4 subnet mask>
RS G8264(config)# ip match­address 1 enable
Enter a filter number from 1 to 256. Specify the IPv4 address and subnet mask of
the network that you want to match. Enable the network filter. You can distribute
up to 256 network filters among 64 route maps each containing 32 access lists.
Steps 2 and 3 are optional, depending on the criteria that you want to match. In
Step 2, the network filter number is used to match the subnets defined in the
network filter. In Step 3, the autonomous system number is used to match the
subnets. Or, you can use both (Step 2 and Step 3) criteria: access list (network filter)
and access path (AS filter) to configure the route maps.
Specify the access list and associate the network filter number configured in Step 1.
RS G8264(config)# route­map 1
RS G8264(config­route­map)# access­list 1 match­address 1
RS G8264(config­route­map)# access­list 1 metric <metric value>
RS G8264(config­route­map)# access­list 1 action deny
RS G8264(config­route­map)# access­list 1 enable
RS G8264(config­route­map)# as­path­list 1 as 1
RS G8264(config­route­map)# as­path­list 1 action deny
RS G8264(config­route­map)# as­path­list 1 enable
If you want to overwrite the attributes that the peer router is sending, define the
following BGP attributes:
Specify up to 32 AS numbers that you want to prepend to a matched route. Use

one space between each of the entries in the list.
 Specify the local preference for the matched route.
<1‐255>(Specify a precedence)