L2circuit is down due to Vlan-id mismatch between MX-80 routers

[NESG]

Hi,

I have configured L2circuit between MX-80 routers, the vc-id on both routers are same but the vlan-id is different. Duw to vlan-id mismatch the L2circuit is not coming up. Is there any options to rewrite the vlan-id??

PE-1

ge-1/1/3 {
    description X-switch-100-6-gi0/2;
    per-unit-scheduler;
    flexible-vlan-tagging;
    speed auto;
    link-mode full-duplex;
    encapsulation flexible-ethernet-services;
    gigether-options {
        auto-negotiation;
    }
    unit 557 {
        encapsulation vlan-ccc;
        vlan-id 557;
    }
}

l2circuit {
    neighbor 10.20.0.2 {
        interface ge-1/1/3.557 {
            virtual-circuit-id 557;
        }
    }

PE-2

ge-1/1/3 {
    flexible-vlan-tagging;
    encapsulation flexible-ethernet-services;
    gigether-options {
        no-auto-negotiation;
    }
    unit 12 {
        vlan-tags outer 12 inner 26;
        family inet {
            address x.x.x.x/24;
        }
    }
    unit 101 {
        vlan-id 101;
        family inet {
            address x.x.x.x/29;
        }
    }
    unit 556 {
        encapsulation vlan-ccc;
        vlan-id 556;
    }
}

l2circuit {
    neighbor 10.20.0.1 {
        interface ge-1/1/3.556 {
            virtual-circuit-id 557;
        }

Below is the output am getting:

 run show l2circuit connections
Layer-2 Circuit Connections:

Legend for connection status (St)
EI -- encapsulation invalid      NP -- interface h/w not present
MM -- mtu mismatch               Dn -- down
EM -- encapsulation mismatch     VC-Dn -- Virtual circuit Down
CM -- control-word mismatch      Up -- operational
VM -- vlan id mismatch           CF -- Call admission control failure
OL -- no outgoing label          IB -- TDM incompatible bitrate
NC -- intf encaps not CCC/TCC    TM -- TDM misconfiguration
BK -- Backup Connection          ST -- Standby Connection
CB -- rcvd cell-bundle size bad  SP -- Static Pseudowire
LD -- local site signaled down   RS -- remote site standby
RD -- remote site signaled down  XX -- unknown

Legend for interface status
Up -- operational
Dn -- down
Neighbor: 10.20.0.1
    Interface                 Type  St     Time last up          # Up trans
    ge-1/1/3.556(vc 557)      rmt   VM (vlan id mismatch)

I tried mutliple options to rewrite the vlan id, which is not working. Can anyone suggest??

[jasonm]

Hi,

Did you try input-vlan-map pop and output-vlan-map push on both ends? That would remove the vlan-id from packets as they pass between the PEs, and disable the 'vlan-id request'.

PE-1

unit 557 {
    encapsulation vlan-ccc;
    vlan-id 557;
    input-vlan-map pop;
    output-vlan-map push;

PE-2

unit 556 {
    encapsulation vlan-ccc;
    vlan-id 556;
    input-vlan-map pop;
    output-vlan-map push;

Or another option is to try and swap the vlan-id on input and output on PE-2:

PE-2

unit 556 {
    encapsulation vlan-ccc;
    vlan-id 556;

    input-vlan-map {
        swap;
        vlan-id 557;
    }

    output-vlan-map {
        swap;
        vlan-id 556;
    }

One of those options should work. I have used a config like this on M320, but i have not tested on MX80, hopefully it will work.

When you have vlans configured with l2circuit the router will send a 'requested VLAN-ID' TLV in the LDP messaging. But when you configure an output map it will disable the vlan-id request, and if the router receives a vlan-id request from a another PE it will check ithe input vlan map to see if it matches.

The last resort is to use a hidden command to disable the vlan-id validation, but using that will most likely move the issue, with your l2circuit up but not able to forward traffic because the vlans are not correct.

HTH

Jason

[mhariry]

Hi,

In JNCIE study guide by Harry Reynolds page 773. it is mentioned that The configuration and verification of translational cross connect (TCC), which is also known as “Layer 2.5 IP-Only Interworking,” was not demonstrated in the chapter body. TCC is supported in CCC, draft-Kompella, and draft-Martini based VPNs to allow for interworking between dissimilar access technologies (or differing VLAN IDs, which are normally required to be the same at both ends of a L2 VPN).

I didn't try before but it might solve your problem

note: interface in this case support either family inet or tcc it couldn't support both families.

Regards,

Mohamed Elhariry

JNCIE-M/T # 1059, CCNP & CCIP

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