Dell Force10 E300, Configuration Manual, Page: 1116 / 1262

1116 | Virtual Routing and Forwarding (VRF)
www.dell.com | support.dell.com
Assign an Interface to a VRF
You must enter the
ip vrf forwarding
command before you configure the IP address or any other setting on
an interface.
When you assign a VLAN interface to a VRF instance, the following conditions apply:
• VLANs assigned to the same VRF have the same MAC address. VLANs assigned to different VRFs
have different MAC addresses. The last four bits of a VLAN’s MAC address correspond to the VRF
ID configured with the
ip vrf
command.
• On a switch port on which multiple VLANs are assigned to different VRFs, the source MAC address
in packets routed on a VRF may not be the same as the MAC address distributed in ARP requests. As
a result, security applications running on neighboring routers that check the source MAC address in
incoming packets may find that the address does not match the ARP-learned MAC address.
• You can assign a static ARP only to a VLAN that is mapped to the default VRF (0) instance .
• By default, all VLANs (4096) are associated with the default VRF until you reassign them to a
non-default VRF with the
ip vrf forwarding
command. You can assign up to 4096 VLANs to a
non-default VRF instance.
• VLANs used with VRF must be Layer 3 VLANs. Layer 2 VLANs can be configured for non-VRF use.
Refer to
Chapter 56, “VLAN,” on page 1099 for complete information.
• All VLAN member ports must be removed from a VLAN that you move from one VRF instance to
another.
Task Command Syntax Command Mode
Create a non-default VRF instance by
specifying a name and VRF ID number, and
enter VRF configuration mode.
The default VRF 0 is automatically configured
when a router with VRF loaded in CAM boots
up.
ip vrf
vrf-name vrf-id
VRF ID range: 1 to 14 and 0 (default
VRF)
CONFIGURATION
Note:
Starting in FTOS 8.4.2.1, when VRF microcode is loaded on a E-Series ExaScale or TeraScale
router, the
ip vrf
[
default-vlan
| vrf-name]
command is deprecated, and is replaced by the
ip vrf
vrf-name
vrf-id
command. The
ip vrf-vlan-block
,
start-vlan-id default-vrf
, and
start-vlan-id
vlan-start-id
commands are
also deprecated.
Note: Starting in release 8.4.1.0, you can configure an IP address or subnet on a physical or VLAN
interface that overlaps the same IP address or subnet configured on another interface only if the
interfaces are assigned to different VRFs. If two interfaces are assigned to the same VRF, you cannot
configure overlapping IP subnets or the same IP address on them.
Task Command Syntax Command Mode
Assign an interface to a VRF instance.
ip vrf forwarding
vrf-name INTERFACE