Cisco IE 4000, Руководство по настройке программного обеспечения

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860
Configuring IP Unicast Routing
Configuring BGP
Before using a prefix list in a command, you must set up the prefix list.
BEFORE YOU BEGIN
Enable BGP routing as described in the Enabling BGP Routing, page 850 .
DETAILED STEPS
To delete a prefix list and all of its entries, use the no ip prefix-list list-name global configuration command. To delete
an entry from a prefix list, use the no ip prefix-list seq seq-value global configuration command. To disable automatic
generation of sequence numbers, use the no ip prefix-list sequence number command; to reenable automatic
generation, use the ip prefix-list sequence number command. To clear the hit-count table of prefix list entries, use the
clear ip prefix-list privileged EXEC command.
EXAMPLE
In the following example, a prefix list is configured to deny the default route 0.0.0.0/0:
Switch(config)# ip prefix-list RED deny 0.0.0.0/0
In the following example, a prefix list is configured to permit traffic from the 172.16.1.0/24 subnet:
Switch(config)# ip prefix-list BLUE permit 172.16.1.0/24
In the following example, a prefix list is configured to permit routes from the 10.0.0.0/8 network that have a mask length
that is less than or equal to 24 bits:
Switch(config)# ip prefix-list YELLOW permit 10.0.0.0/8 le 24
In the following example, a prefix list is configured to deny routes from the 10.0.0.0/8 network that have a mask length
that is greater than or equal to 25 bits:
Switch(config)# ip prefix-list PINK deny 10.0.0.0/8 ge 25
Command Purpose
1. configure terminal Enter global configuration mode.
2. ip prefix-list list-name [ seq seq-value ]
deny | permit network / len [ ge
ge-value ] [ le le-value ]
Create a prefix list with an optional sequence number to
deny or permit access for matching conditions. You must
enter at least one permit or deny clause.

network / len is the network number and length (in bits)
of the network mask.

(Optional) ge and le values specify the range of the
prefix length to be matched. The specified ge-value
and le-value must satisfy this condition: len < ge-value
< le-value < 32
3. ip prefix-list list-name seq seq-value
deny | permit network / len [ ge
ge-value ] [ le le-value ]
(Optional) Add an entry to a prefix list, and assign a
sequence number to the entry.
4. end Return to privileged EXEC mode.
5. show ip prefix list [ detail | summary ]
name [ network / len ] [ seq seq-num ]
[ longer ] [ first-match ]
Verify the configuration by displaying information about a
prefix list or prefix list entries.
6. copy running-config startup-config (Optional) Save your entries in the configuration file.