Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
Community Member

VRF Lite question

I have a quick question. We are ready to use VRF Lite but was wondering if it's possible to use the same dlci for 2 different VRF's on the same PE running frame-relay switching w/o any conflicts. Any help would be appreciated.

example on Same PE:

VRF A:

int s0.1: dlci 16

int s0.2: dlci 17

VRF B:

int s1.1: dlci 16

int s1.2: dlci 17

4 REPLIES
Silver

Re: VRF Lite question

If the two serial interfaces above are connecting to the same frame-relay switch, then it will not work. This is because the frame-relay switch is not vrf or VPN aware. However, it could work if the serial interfaces were connecting to two different frame-relay switches. The layer 2 and 3 tables will be seperate on the PE, and the frame-relay switches will be aware of only one dlci for which to switch to a unique interface.

Re: VRF Lite question

Hello,

I am not clearly understanding, what you would like to achieve.

FR switching allows a router to forward frames with a certain DLCI received on a specific interface to another interface. There is no VRF involved nor can two VRFs be interconnected within a router this way.

Hope this helps! Please rate all posts.

Regards, Martin

Community Member

Re: VRF Lite question

As you dont specify DLCIs when configuring VRFs, the question of using the same dlci numbers in different VRFs boils down to whether you can actually receive the same dlci number on different interfaces. DLCIs are per interface resources and indeed of you are connecting to two different FR switches you could receive the same number on different interfaces. This wouldnt work if you are connecting to the same switch as the switch assigns and swtiches dlcis per interface.

Herbert

Hall of Fame Super Silver

Re: VRF Lite question

Hello hsk10,

there is no problem on using the same DLCI on different serial interfaces even if connecting to same router acting as a frame-relay switch, because frame-relay route command is given in interface configuration mode.

You are allowed also to mix L2 and L3 functionalities on the same interface but only if they are using different DLCIs: you cannot at the same time perform FR switching and providing a VRF access link on the same DLCI.

Example:

interface Serial3/3

no ip address

encapsulation frame-relay

no fair-queue

serial restart_delay 0

frame-relay intf-type dce

frame-relay route 705 interface Serial3/2 507

frame-relay route 706 interface Serial3/5 607

!

interface Serial3/3.652 point-to-point

description FR link-l2tvp3-c3745b

ip address 33.x.x.x.255.255.252

frame-relay interface-dlci 652

!

interface Serial3/3.701 point-to-point

ip address 192.168.37.6 255.255.255.252

frame-relay interface-dlci 701

!

hope to help

giuslar

197
Views
0
Helpful
4
Replies
CreatePlease to create content