Cisco Catalyst 4500 Series, Software Configuration Manual

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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 43 Configuring VRF-lite
Configuring VRF-lite for IPv4
•
A Catalyst 4500 series switch using VRF can support one global network and up to 64 VRFs. The
total number of routes supported is limited by the size of the TCAM.
• A single VRF can be configured for both IPv4 and IPv6.
•
PBR and VRF cannot be configured on the same interface. Similarly, WCCP, Etherchannel and MEC
cannot be configured on the same interface with VRF.
• If an incoming packet's destination address is not found in the vrf table, the packet is dropped. Also,
if insufficient TCAM space exists for a VRF route, hardware switching for that VRF is disabled and
the corresponding data packets are sent to software for processing.
IPv4 Specific
•
You can use most routing protocols (BGP, OSPF, EIGRP, RIP and static routing) between the CE
and the PE. However, we recommend using external BGP (EBGP) for these reasons:
–
BGP does not require multiple algorithms to communicate with multiple CEs.
– BGP is designed for passing routing information between systems run by different
administrations.
–
BGP makes simplifies passing attributes of the routes to the CE.
• VRF-lite does not support IGRP and ISIS.
•
Beginning with Cisco IOS Release 12.2(50)SG, Multicast and VRF can be configured together on a
Layer 3 interface.
•
The Catalyst 4500 series switch supports all the PIM protocols (PIM-SM, PIM-DM, PIM-SSM, PIM
BiDIR).
•
The capability vrf-lite subcommand under router ospf should be used when configuring OSPF as
the routing protocol between the PE and the CE.
IPv6 specific
• VRF-aware OSPFv3, BGPv6, EIGRPv6, and IPv6 static routing are supported.
•
VRF aware ISISv6, RIPng, IPv6 Multicast Routing(MVRF), and PIMv6 are not supported.
• VRF-aware IPv6 route applications include: ping, telnet, ssh, tftp, ftp and traceroute. (This list does
not include the Mgt interface, which is handled differently even though you can configure both IPv4
or IPv6 VRF under it.)
Configuring VRF-lite for IPv4
Configuring VRFs
To configure one or more VRFs, perform this task:
Command Purpose
Step 1
Switch# configure terminal
Enters global configuration mode.
Step 2
Switch(config)# ip routing
Enables IP routing.
Step 3
Switch(config)# ip vrf vrf-name
Names the VRF and enters VRF configuration mode.