Q in Q questions

[liviu.sisu]

I have the following config running on 1800 series router :

!

bridge irb

bridge 1 priority 0

bridge 1 protocol ieee

bridge 1 route ip

bridge 1 aging-time 60

interface BVI1

mac-address 001c.5817.6431

ip address 2.2.2.10 255.255.255.0

no ip redirects

ip local-proxy-arp

ip route-cache same-interface

interface FastEthernet0.30031

encapsulation dot1Q 300 second-dot1q 31

no snmp trap link-status

bridge-group 1

bridge-group 1 spanning-disabled

!

interface FastEthernet0.30032

encapsulation dot1Q 300 second-dot1q 32

no snmp trap link-status

bridge-group 1

bridge-group 1 spanning-disabled

The problem is when I try to ping a subinterface, the router tags the reply only with outer vlan tag (300).

When I use simple vlan subinterfaces all goes OK.

I would like to know if this config should work on this platform or not, I have been trying it on 1800 series and 2800 series routers.

If it should work, what am I missing ?

Thanks,

Liviu Sisu

[milan.kulik]

Hi,

what do you mean by "when I try to ping a subinterface" here?

The subinterfaces don't have any IP addresses assigned, so how to Ping them?

You mean to pinging the BVI1 IP address?

But how would the router know which subinterface to use for the answer when both configured on the same physical interface Fa0?

IMHO, this might work on two different interfaces of one switching module, e.g., but not configured on one physical router interface.

HTH,

Milan

[codrin_botezatu]

Hi,

Yes you are right...the ping is to BVI interface IP which should answer for all subinterfaces associated to same bridge-group. This is the idea of the setup to have different VLANs working as same broadcast domain and the router should learn what subinterface to use for reply when the icmp request is comming.

I have tested same scenario with simple dot1q subinterfaces on same physical port and is working fine.

With QinQ don't know what's happening and no double tagging the icmp reply...it is tagging the outerVLAN only

Thanks,

  Codrin

[codrin_botezatu]

Tested on 2600 and same bahavior...does enyone could test on more powerfull platforms?

[liviu.sisu]

Hi,

Has anybody experienced the same behavior ? Or at least try to implement a similar solution which worked?

Thanks!