Dell Brocade DCX, Configuration Manual

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BigIron RX Series Configuration Guide 803
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Filtering
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Matching based on next-hop router
You can use the results of an IP ACL or an IP prefix list as the match condition.
To construct a route map that matches based on the next-hop router, enter commands such as the
following.
BigIron RX(config)# route-map HopMap permit 1
BigIron RX(config-routemap HopMap)# match ip next-hop 2
Syntax: match ip next-hop <num>
Syntax: match ip next-hop prefix-list <name>
The <num> parameter with the first command specifies an IP ACL and can be a number from 1 –
199 or the ACL name if it is a named ACL. To configure an IP ACL, use the ip access-list or
access-list command. Refer to
Chapter 21, “Access Control List” .
The <name> parameter with the second command specifies an IP prefix list name. To configure an
IP prefix list, refer to “Defining and applying IP prefix lists” on page 797.
Matching based on the route source
To match a BGP4 route based on its source, use the match ip route-source statement. Here is an
example.
BigIron RX(config)# access-list 10 permit 192.168.6.0 0.0.0.255
BigIron RX(config)# route-map bgp1 permit 1
BigIron RX(config-routemap bgp1)# match ip route-source 10
The first command configures an IP ACL that matches on routes received from 192.168.6.0/24.
The remaining commands configure a route map that matches on all BGP4 routes advertised by
the BGP4 neighbors whose addresses match addresses in the IP prefix list. You can add a set
statement to change a route attribute in the routes that match. You also can use the route map as
input for other commands, such as the neighbor and network commands and some show
commands.
Syntax: match ip route-source <acl> | prefix <name>
The <acl> | prefix <name> parameter specifies the name or ID of an IP ACL, or an IP prefix list.
Matching on routes containing a specific set of communities
BigIron RX enables you to match routes based on the presence of a community name or number in
a route. To match based on a set of communities, configure a community ACL that lists the
communities, then compare routes against the ACL.
Here is an example.
BigIron RX(config)# ip community-list standard std_1 permit 12:34 no-export
BigIron RX(config)# route-map bgp2 permit 1
BigIron RX(config-routemap bgp2)# match community std_1 exact-match
The first command configures a community ACL that contains community number 12:34 and
community name no-export. The remaining commands configure a route map that matches the
community attributes field in BGP4 routes against the set of communities in the ACL. A route
matches the route map only if the route contains all the communities in the ACL and no other
communities.
Syntax: match community <acl> exact-match