Re: EoMPLS VC type/MTU

Antonio_1_2 · ‎12-13-2010

Hello,

on one side I have PE Cisco 6506 and on the other side PE is Cisco 2811.

I want to Implement EoMPLS and the tunnel is down.

C2811:

interface FastEthernet0/1
no ip address
mpls mtu 1550
!

interface FastEthernet0/1.3000
encapsulation dot1Q 3000
no cdp enable
xconnect 10.11.0.1 3000 encapsulation mpls

C6506:

interface GigabitEthernet1/1
mtu 9216
no ip address
!
interface GigabitEthernet1/1.3000
encapsulation dot1Q 3000
xconnect 10.10.0.1 3000 encapsulation mpls

!

other EoMPLS connections

!

After some troubleshooting I found two problems:

1) VC types are differrent

2) MTUs, on interfaces under which xconnect is configured, are different.On Cisco 6506 is 9218 Bytes and on Cisco2811 is 1500 Bytes

1)

debug message on c2811:

: Mismatch vc type in remote label binding, local 4, remote 5

c2811#show mpls l2transport binding 3000
Destination Address: 10.11.0.1, VC ID: 3000
    Local Label: 27
        Cbit: 1,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a

        VCCV: CC Type: CW [1], RA [2]
              CV Type: LSPV [2]
    Remote Label: 320
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV: CC Type: RA [2]
              CV Type: LSPV [2]

c6506#show mpls l2transport binding 3000
Destination Address: 10.10.0.1, VC ID: 3000
    Local Label: 320
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: Type 2
    Remote Label: 27
        Cbit: 1,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a

VCCV Capabilities: Type 1, Type 2

Is it problem with IOS bug? Can it be somehow forced on c6506 "vc type 4" for this connection? Because all other connections are automatically type 4 on this router. This only happens when EoMPLS is 2811 - 6500. on 2811-7200 there is no vc type mismatch.

2) I tried to set MTU to 1500 under C6506 Gi1/1.3000 subinterfaces but it isn't allowed. On 2811 Fa0/1 can't be bigger than 1500Bytes. I tried to set mpls MTU under subinterfaces Fa0/1.300 tu mpls mtu 9216 but it didn't help.

Is there some workaround or MTUs HAVE to be equal on both physical interfaces?

regards,

A.

Mahesh Gohil · ‎12-13-2010

Hello,

Can you try below mtu setting because mtu should be same at both end. You can see this by sh mpls l2 vc 3000 detail command

2811

interface FastEthernet0/1
mtu 1500
!

C6506:

interface GigabitEthernet1/1
mtu 1500

To change vc-type try below <<

pw-class TEST

encapsulation mpls

internetworking ethernet

and call above in

xconnect encapsulation mpls pw-class TEST

Regards

Mahesh

Antonio_1_2 · ‎12-14-2010

Thank you Mahesh-

I managed to change VC type with your suggestion, but I can't lower MTU on Gi1/1 to 1500Bytes because I already have a lot of

EoMPLS connections configured under the same interface (and those connections require MTU with 9216Bytes).

So there is no way to change only subinterface MTU?

regards,

A

Antonio_1_2 · ‎12-14-2010

Hi,

I also want to ask if this is now regular situation. Since I have configuration like this :

pseudowire-class TEST

encapsulation mpls

internetworking ethernet

interface FastEthernet0/1.3000
encapsulation dot1Q 3000
no cdp enable
xconnect 10.11.0.1 3000 pw-class TEST

Now I have port mode EoMPLS (VC Type: Ethernet)

but on each side I have SUBinterfaces (and under subinterfaces I have configured port mode EoMPLS)

c2811#sh mpls l2transport binding
Destination Address: 10.11.0.1, VC ID: 3000
    Local Label: 27
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc:n/a
        VCCV: CC Type: CW [1], RA [2]
              CV Type: LSPV [2]
    Remote Label: 559
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV: CC Type: RA [2]
              CV Type: LSPV [2]

can I have configuraton like this? Is it possible that it will interact with existing EoMPLS connections (under same physical interface, but differnet dot1q subinterface). Al other EoMPLS conections are VLAN mode.

Destination Address: 10.20.0.1, VC ID: 3500
    Local Label: 258
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc:
        VCCV Capabilities: Type 2
    Remote Label: 367
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc:
        VCCV Capabilities: None
Destination Address: 10.0.0.1, VC ID: 3600
    Local Label: 259
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc:
        VCCV Capabilities: Type 2
    Remote Label: 81
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc:
        VCCV Capabilities: None
Destination Address: 10.0.0.1, VC ID: 3100
    Local Label: 265
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: Type 2
    Remote Label: 340
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: None
Destination Address: 10.4.0.1, VC ID: 3200
    Local Label: 264
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: Type 2
    Remote Label: 300
        Cbit: 0,    VC Type: Eth VLAN,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: None
Destination Address: 10.10.0.1, VC ID: 3000
    Local Label: 559
        Cbit: 0,    VC Type: Ethernet,    GroupID: 0
        MTU: 9216,   Interface Desc: n/a
        VCCV Capabilities: Type 2
    Remote Label: 27
        Cbit: 1,    VC Type: Ethernet,    GroupID: 0
        MTU: 1500,   Interface Desc: n/a
        VCCV Capabilities: Type 1, Type 2

As you can notice only the last conecction has VC type Ethernet, and all of them are under same physical interface

regards,

A.

Mahesh Gohil · ‎12-14-2010

Hi,

Every sub-interface is different entity so it will work though it is part of same physical interface.

Regards

Mahesh

Antonio_1_2 · ‎12-14-2010

Thanks Mahesh,

and regarding MTU, there is no way that some subinterfaces have different MTUs (i.e. one subinterface have 1500 bytes MTU and other 1900Bytes MTU, on the same physical interface) ?

There is not workaround?

Because I can't lower MTU on my Gig1/1 interface and I have already few xconnect links which need MTU larger than 1500Bytes

Regards,

A.

Mahesh Gohil · ‎12-14-2010

Hi,

I confirm that sub-interface mtu can no be changes. The only option is to change mtu on main interface

but as you change mtu at gig all l2 link will go down.

You should tackle this by plan any downtime window and change mtu to 1600 or any value which is supported at both end like

i do for my network

by the way mtu setting require careful planning. So my suggestion is to plan it before you do anything with your network

consistent mtu is require for your network

regards

mahesh

shijthom · ‎12-22-2010

Did you try configuring it under the xconnect? This will be applicable for the xconnect alone without changing the interface mtu

interface xxx/x.x
xconnect ..
mtu xxx

Antonio_1_2 · ‎12-23-2010

Hello,

I've tried but router doesn't allow me this command:

router(config)#interface FastEthernet0/1.3000
router(config-subif)#xconnect 10.11.0.1 3000 encapsulation mpls

router(config-subif-xconn)#?
Xconnect configuration commands:
backup   Xconnect backup configuration commands
default Set a command to its defaults
exit     Exit from Xconnect submode configuration
no       Negate a command or set its defaults
remote   Xconnect remote peer configuration commands

router(config-subif-xconn)#mtu 9000 ?
% Unrecognized command

router(config-subif-xconn)#mtu 9000
^
% Invalid input detected at '^' marker.

IOS is C2800NM-SPSERVICESK9-M), Version 12.4(15)T14

Regards,

A

Mahesh Gohil · ‎12-23-2010

Hi A,

I don't think this is possible option. You can change MTU under physical interface and

not under sub-interface.

As I told prepare proper plan to chenge mtu across network and go ahead with implementation

Regards

Mahesh

mwalters · ‎09-12-2012

Setting the MTU under the xconnect config is available on 15.1(1)S2, and allowed a problematic tunnel to come up for us.

In our scenario we are upgrading our network from 1546 to 9216 MTU, but cannot do it all at once. This command has helped us during the transition.

Cheers

Mark

npritchett · ‎02-12-2016

This recently became available on my Catalyst 6500 platform and saved my bacon.