Cisco Cisco IOS Software Release 12.2(27)SBC
BGP Support for IP Prefix Import from Global Table into a VRF Table
How to Import IP Prefixes from Global Table into a VRF Table
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Cisco IOS Release: Multiple releases (see the Feature History table)
DETAILED STEPS
What to Do Next
Proceed to the next task to create the VRF and configure the import route map.
Creating the VRF and the Import Route Map
The IP prefixes that are defined for import are then processed through a match clause in a route map. IP
Prefixes that pass through the route map are imported into the VRF. A maximum of 5 VRFs per router
can be configured to import IPv4 prefixes from the global routing table. 1000 prefixes per VRF are
imported by default. You can manually configure from 1 to 2147483647 prefixes for each VRF. We
recommend that you use caution if you manually configure the prefix import limit. Configuring the
router to import too many prefixes can interrupt normal router operation.
Prefixes that pass through the route map are imported into the VRF. A maximum of 5 VRFs per router
can be configured to import IPv4 prefixes from the global routing table. 1000 prefixes per VRF are
imported by default. You can manually configure from 1 to 2147483647 prefixes for each VRF. We
recommend that you use caution if you manually configure the prefix import limit. Configuring the
router to import too many prefixes can interrupt normal router operation.
MPLS and Route Target Configuration Is Not Required
No MPLS or route target (import/export) configuration is required.
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
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Enter your password if prompted.
Step 2
configure
terminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
access-list
access-list-number {deny | permit}
source [source-wildcard] [log]
Example:
Router(config)# access-list 50 permit 10.1.1.0
0.0.0.255 permit
Creates an access list and defines a range of IP prefixes to
import into the VRF table.
import into the VRF table.
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The example creates a standard access list numbered
50. This filter will permit traffic from any host with an
IP address in the 10.1.1.0/24 subnet.
50. This filter will permit traffic from any host with an
IP address in the 10.1.1.0/24 subnet.
Step 4
ip prefix-list
prefix-list-name [seq seq-value]
{deny network/length | permit network/length}
[ge ge-value] [le le-value]
Example:
Router(config)# ip prefix-list COLORADO permit
10.24.240.0/22
Creates a prefix-list and defines a range of IP prefixes to
import into the VRF table.
import into the VRF table.
•
The example creates an IP prefix list named
COLORADO. This filter will permit traffic from any
host with an IP address in the 10.24.240.0/24 subnet.
COLORADO. This filter will permit traffic from any
host with an IP address in the 10.24.240.0/24 subnet.