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How to verify VPLS mac-address forwarding

mtiger
Level 1
Level 1

I think VPLS know how to forward by mac-address. but how to verify it ?

for example I show mac-address vlan 100. But I can not find a command to verify How mac-address is forwarding ?

at 6509:

PA_C76_1>sh mpls l2transport vc

Local intf Local circuit Dest address VC ID Status

------------- -------------------- --------------- ---------- ----------

VFI PA-LA-test VFI 203.160.227.88 100 UP

VFI PA-LA-test VFI 203.160.227.95 100 UP

PA_C76_1>show mac-address-table vlan 100

Legend: * - primary entry

age - seconds since last seen

n/a - not available

vlan mac address type learn age ports

------+----------------+--------+-----+----------+--------------------------

* 100 000b.45b6.bc40 dynamic Yes 95 Router

* 100 0012.d946.59c1 dynamic Yes 10 Gi4/1

9 Replies 9

swaroop.potdar
Level 7
Level 7

Hi,

VPLS provides the medium to for a E-LAN, and in Cisco implementations, the MAC learning is not actually done by a VPLS instance.

This can be best explained by an example.

PE(SW)-A ---- PE(SW)-B

\ /

\ /

\ /

PE(SW)-C

Now these three PE nodes under VPLS, are only provided the medium to connect to each other using P2P PW forming a full mesh.

For simplicity you can assume they are three switches connected in the above manner using copper. So this copper connecitivity is provided by VPLS.

And at the end of the day the end nodes learn mac addresses using the conventional method of flooding and learning. So you wont find any VPLS specific commands to see what mac address is the VPLS instance flooding. As its only providing a medium for connectivty. And the flooding is done by the end nodes. as they treat the VPLS VC as one of the outgoing port.

HTH-Cheers,

Swaroop

To add a note, since I mentioned you wont find a VPLS specific command to know what MAC addresses are flooded or learned on which VC.

May be you would find this command of some help.

"show mpls ttfib"

This command when coupled with the

"show mpls l2transport vc detail"

should be of help to get the answer you want.

HTH-Cheers,

Swaroop

Thanks for you answer.

But I can not find the command "show mpls ttfib" on 7600 with sup720-3BXL 12.2(18)SXF5.

Brs,

Michael

Nor could I. I had to run "sh mpls tp tunnel-tp ?". I am running this command on an ASR-920(CPE). I don't even know if this was the correct command abbreviated   (tttp). Anyway, hope it helps you out.

sultan-shaikh
Level 3
Level 3

Hi Swaroop,

I have something to add here, do let me know if my thinking is correct...

We can see the VFI table (Virtual Forwarding Instance table) to which attachment circuits are associated.

Below are the commands you would give on PE to check the MAC forwarding...

a) "sh vfi l2vpn" - to see VFI status

- This will give you local AC (Vlan) and neighbours connected via PW...

b) "show mac-address-table vlan 10" (the vlan is as seen in the "sh vfi l2vpn" command)

- This command will give you the MAC addresses learnt for the specific VFI instance...

Is this okay or am I missing something...

Thanks

Cheers,

~sultan

Hi Sultan,

Actually the orginal poster already has the same commands. Which can help us see which vlan is used for VFI.

And the second command in the original poster gives us the mac addresses learnt.

So going ahead if we wanted to have a Tunnel/VC label to MAC address mapping with the interface. would give us more clearer idea as to which mac would be forwarded out on which tunnel/vc/pw.

I am sure you are with me in my understanding.

HTH-Cheers,

Swaroop

PS: I physically checked this command on a SUP720, with SXE and yes it does NOT work.

I will see if I can pass on a equivalent command if its is available.

Mtiger & Sultan,

I checked out but the command equivalent to "show mpls ttfib" is not present till my awareness goes.

Anyways, Mtiger you have those two commands which you specified to verify about VPLS, and also the explanation which I gave in my original reply stands.

HTH-Cheers!,

Swaroop

Dears,

I find the "show mpls ttfib" ( attch OSM module).

But I can not find usefull information.

CWTLC-Slot3#sh mpls ttfib

Local Outgoing Packets Tag LTL Dest. Destination Outgoing

Tag Tag or VC Switched Index Vlanid Mac Address Interface

16 Punt2Earl7 0

17 Punt2Earl7 0

...

340 EoM disp 0

341 Punt2Earl7 0

....

Chang,

Was referring to the command "show mpls ttfib" on the supervisor not on the OSM. You can serach for this command on the Cisco.com site and see the output it gives.

If you are looking for something more specific than this, then you can may be explain the requirement again.

HTH-Cheers,

Swaroop

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