2-197
Catalyst 3750 Metro Switch Command Reference
OL-9645-10
Chapter 2 Catalyst 3750 Metro Switch Cisco IOS Commands
ip vrf (global configuration)
–
16-bit AS number: your arbitrary 32-bit number (for example, 101:3)
–
32-bit IP address: your arbitrary 16-bit number (for example, 192.168.122.15:1.)
•
route-target
{
import
|
export
|
both
}
route-target-ext-community
: specifies target VPN extended
communities. You can specify the target for export, import, or both.
To return to global configuration mode, use the
exit
command. To return to privileged EXEC mode, use
the
end
command.
The switch supports a total of 26 VRFs and VPNs.
Use an import route map when an application requires finer control over the routes imported into a VRF
than provided by the import and export extended communities configured for the importing and
exporting VRF. The
import map
command associates a route map with the specified VRF. By using a
route map, you can filter routes that are eligible for import into a VRF, based on the route target extended
community attributes of the route. The route map might deny access to selected routes from a community
that is on the import list.
If you set a maximum routes threshold, the switch rejects routes when the threshold limit is reached. If
you enter
warn-only
, the switch issues a syslog error message when the maximum number of VRF
routes exceeds the allowed limit, but still allows additional routes.
An RD creates routing and forwarding tables and specifies the default route distinguisher for a VPN. You
must configure a route distinguisher for a VRF to be functional. The RD is added to the beginning of the
customer's IPv4 prefixes to change them into globally unique VPN-IPv4 prefixes.
The route target specifies a target VPN extended community. Like a route-distinguisher, an extended
community is composed of either an autonomous system number and an arbitrary number or an IP
address and an arbitrary number.
The
ip vrf
vrf-name
command creates a VRF routing table and a Cisco Express Forwarding (CEF)
forwarding table, both named
vrf-name
. Associated with these tables is the default route distinguisher
value
route-distinguisher
.
Examples
This example shows how to create the VRF named
vpn1
, enter VRF configuration mode, and import a
route map to the VRF:
Switch(config)#
ip vrf vpn1
Switch(config-vrf)#
rd 100:2
Switch(config-vrf)#
route-target both 100:2
Switch(config-vrf)#
route-target import 100:1
Related Commands
Command
Description
ip vrf (interface configuration)
Associates a VRF routing table or a route map with an interface.
show ip route vrf
Displays the IP routing table associated with a VRF. For syntax
information, select
Cisco IOS Release 12.2 Configuration Guides
and Command References > Cisco IOS Switching Services
Command Reference, Release 12.2
.
show ip vrf
Displays display the set of defined VRFs and associated
interfaces. For syntax information, select
Cisco IOS Release 12.2
Configuration Guides and Command References > Cisco IOS
Switching Services Command Reference, Release 12.2
.
