Dell PowerConnect B-FCXs, Руководство по настройке

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1052 PowerConnect B-Series FCX Configuration Guide
53-1002266-01
Filtering
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PowerConnect(config)#ip prefix-list Routesfrom1234 deny 20.20.0.0/24
PowerConnect(config)#ip prefix-list Routesfrom1234 permit 0.0.0.0/0 le 32
PowerConnect(config)#router bgp
PowerConnect(config-bgp-router)#neighbor 1.2.3.4 prefix-list Routesfrom1234 in
PowerConnect(config-bgp-router)#neighbor 1.2.3.4 capability orf prefixlist send
The first two commands configure statements for the IP prefix list Routesfrom1234. The first
command configures a statement that denies routes to 20.20.20./24. The second command
configures a statement that permits all other routes. (Once you configure an IP prefix list
statement, all routes not explicitly permitted by statements in the prefix list are denied.)
The next two commands change the CLI to the BGP4 configuration level, then apply the IP prefix list
to neighbor 1.2.3.4. The last command enables the Layer 3 Switch to send the IP prefix list as an
ORF to neighbor 1.2.3.4. When the Layer 3 Switch sends the IP prefix list to the neighbor, the
neighbor filters out the 20.20.0.x routes from its updates to the Layer 3 Switch. (This assumes that
the neighbor also is configured for cooperative filtering.)
The <ip-addr> | <peer-group-name> parameter specifies the IP address of a neighbor or the name
of a peer group of neighbors.
The send | receive parameter specifies the support you are enabling:
•
send – The Layer 3 Switch sends the IP prefix lists to the neighbor.
•
receive – The Layer 3 Switch accepts filters from the neighbor.
If you do not specify the capability, both capabilities are enabled.
The prefixlist parameter specifies the type of filter you want to send to the neighbor.
NOTE
The current release supports cooperative filtering only for filters configured using IP prefix lists.
Sending and receiving ORFs
Cooperative filtering affects neighbor sessions that start after the filtering is enabled, but do not
affect sessions that are already established.
To activate cooperative filtering, reset the session with the neighbor. This is required because the
cooperative filtering information is exchanged in Open messages during the start of a session.
To place a prefix-list change into effect after activating cooperative filtering, perform a soft reset of
the neighbor session. A soft reset does not end the current session, but sends the prefix list to the
neighbor in the next route refresh message.
NOTE
Make sure cooperative filtering is enabled on the Layer 3 Switch and on the neighbor before you
send the filters.
To reset a neighbor session and send ORFs to the neighbor, enter a command such as the
following.
PowerConnect#clear ip bgp neighbor 1.2.3.4
This command resets the BGP4 session with neighbor 1.2.3.4 and sends the ORFs to the neighbor.
If the neighbor sends ORFs to the Layer 3 Switch, the Layer 3 Switch accepts them if the send
capability is enabled.