User guide

Configuring BGP Routing Policies
OmniSwitch AOS Release 7 Advanced Routing Configuration Guide March 2015 page 4-83
Creating a Prefix List Policy
Prefix policies filter routes based on network addresses and their masks. You can also set prefix upper and
lower limits to filter a range of network addresses.
To create a prefix list policy:
1 Name the policy and specify the IP network address and mask using the ip bgp policy prefix-list
command, as shown:
-> ip bgp policy prefix-list prefixfilter 12.0.0.0 255.0.0.0
Prefix policy prefixfilter now filters routes that match the network address 12.0.0.0 with a mask of
255.0.0.0.
2 Set the policy action using the ip bgp policy prefix-list action command. The policy action either
permits or denies routes that match the filter. Permitted routes are advertised, while denied routes are not.
For example:
-> ip bgp policy prefix-list prefixfilter 12.0.0.0 255.0.0.0 action deny
Prefix policy prefixfilter now denies routes that match the network address 12.0.0.0 with a mask of
255.0.0.0.
3 Optionally, you can set a lower prefix limit on the addresses specified in the policy using the ip bgp
policy prefix-list ge command. For example:
-> ip bgp policy prefix-list prefixfilter 14.0.0.0 255.0.0.0 ge 16
Prefix policy prefixfilter now denies routes after 14.0.0.0/16.
4 Optionally, you can set an upper prefix limit on the addresses specified in the policy using the ip bgp
policy prefix-list le command. For example:
-> ip bgp policy prefix-list prefixfilter 14.0.0.0 255.0.0.0 le 24
Prefix policy prefixfilter now denies routes between 14.0.0.0/16 and 14.0.0.0/24
Creating a Prefix6 List Policy
Prefix6 policies filter routes based on IPv6 prefixes. You can also set prefix6 upper and lower limits for
the minimum length of the prefix to be matched.
To create a prefix6 list policy:
1 Name the policy and specify the IPv6 address and the prefix length using the ip bgp policy prefix6-list
command, as shown:
-> ip bgp policy prefix6-list uniqLocal FC00::/48
Prefix policy uniqLocal now filters routes that match the address FC00 with a prefix length of 48.
2 Set the policy action using the ip bgp policy prefix6-list action command. The policy action either
permits or denies routes that match the filter. Permitted routes are advertised, while denied routes are not.
For example:
-> ip bgp policy prefix6-list uniqLocal FC00::/48 action permit
Prefix policy uniqLocal now permits routes that match the address FC00 with a prefix length of 48.