Filtering Specific Ip Addresses - Foundry Networks Switch and Router Installation And Configuration Manual

Foundry Switch and Router Installation and Configuration Guide
Syntax: [no] bgp-redistribute-internal
To disable redistribution of IBGP routes into RIP and OSPF, enter the following command:
BigIron(config-bgp-router)# no bgp-redistribute-internal
USING THE WEB MANAGEMENT INTERFACE
You cannot configure this parameter using the Web management interface.

Filtering Specific IP Addresses

You can configure the router to explicitly permit or deny specific IP addresses received in updates from BGP4
neighbors by defining IP address filters. The router permits all IP addresses by default. You can define up to 100
IP address filters for BGP4.
• If you want permit to remain the default behavior, define individual filters to deny specific IP addresses.
• If you want to change the default behavior to deny, define individual filters to permit specific IP addresses.
NOTE: Once you define a filter, the default action for addresses that do not match a filter is "deny". To change
the default action to "permit", configure the last filter as "permit any any".
Address filters can be referred to by a BGP neighbor's distribute list number as well as by match statements in a
route map.
NOTE: If the filter is referred to by a route map's match statement, the filter is applied in the order in which the
filter is listed in the match statement.
NOTE: You also can filter on IP addresses by using IP ACLs. See "Using Access Control Lists (ACLs)".
To define an IP address filter, use either of the following methods.
USING THE CLI
To define an IP address filter to deny routes to 209.157.0.0, enter the following command:
BigIron(config-bgp-router)# address-filter 1 deny 209.157.0.0 255.255.0.0
Syntax: address-filter <num> permit | deny <ip-addr> <wildcard> <mask> <wildcard>
The <num> parameter is the filter number.
The permit | deny parameter indicates the action the Layer 3 Switch takes if the filter match is true.
• If you specify permit, the Layer 3 Switch permits the route into the BGP4 table if the filter match is true.
• If you specify deny, the Layer 3 Switch denies the route from entering the BGP4 table if the filter match is
true.
NOTE: Once you define a filter, the default action for addresses that do not match a filter is "deny". To change
the default action to "permit", configure the last filter as "permit any any".
The <ip-addr> parameter specifies the IP address. If you want the filter to match on all addresses, enter any.
The <wildcard> parameter specifies the portion of the IP address to match against. The <wildcard> is a four-part
value in dotted-decimal notation (IP address format) consisting of ones and zeros. Zeros in the mask mean the
packet's source address must match the <source-ip>. Ones mean any value matches. For example, the
<ip-addr> and <wildcard> values 209.157.22.26 0.0.0.255 mean that all hosts in the Class C sub-net 209.157.22.x
match the policy.
If you prefer to specify the wildcard (mask value) in Classless Interdomain Routing (CIDR) format, you can enter a
forward slash after the IP address, then enter the number of significant bits in the mask. For example, you can
enter the CIDR equivalent of "209.157.22.26 0.0.0.255" as "209.157.22.26/24". The CLI automatically converts
the CIDR number into the appropriate mask (where zeros instead of ones are the significant bits) and changes the
19 - 48 December 2000