ASR1001 and 2x2960 switch config

[Mark3205]

i,

I'm hoping for a bit of advise.

I have been tasked to reconfigure 2 switches( 2x2960) and 1 router (ASR1001) that are currently connected with a ROAS config with only one trunk between the ASR and SW1 and another trunk between SW1 and SW2. Each SW has multiple vlans and the connected devices need to be able to communicate with each other in different vlans.

i would like to be able to connect a second trunk from SW2 to the router and maintain the trunk between SW1&2 and implement spanning tree to avoid any L2 loops. 

The problem i am running into is the ip addressing for the sub-int of the second trunk. researching it on the cisco forums suggest that bridging would be a better option.

I have looked at creating a bridge group but the ASR will not accept the following code.

bridge irb

interface GigabitEthernet0/0.20

  bridge-group 20

interface GigabitEthernet0/1.20

  bridge-group 20

It says that the sub-int bridge-group cmd is unrecognised.

Is it the router or me.

Any suggestions welcome.

Thanks

[Mark3205]

i,

I'm hoping for a bit of advise.

I have been tasked to reconfigure 2 switches( 2x2960) and 1 router (ASR1001) that are currently connected with a ROAS config with only one trunk between the ASR and SW1 and another trunk between SW1 and SW2. Each SW has multiple vlans and the connected devices need to be able to communicate with each other in different vlans.

i would like to be able to connect a second trunk from SW2 to the router and maintain the trunk between SW1&2 and implement spanning tree to avoid any L2 loops. 

The problem i am running into is the ip addressing for the sub-int of the second trunk. researching it on the cisco forums suggest that bridging would be a better option.

I have looked at creating a bridge group but the ASR will not accept the following code.

bridge irb

interface GigabitEthernet0/0.20

  bridge-group 20

interface GigabitEthernet0/1.20

  bridge-group 20

It says that the sub-int bridge-group cmd is unrecognised.

Is it the router or me.

Any suggestions welcome.

Thanks

[sandysp4u]

hello Mark

You can simply configure subinterfaces on the second port and assign an IP add to each sub interface as per your need also configure the switch interfaces connecting to the router as trunk it will solve your problem. Maybe I could have not understood your issue I would like you to help me understand it.

Editing my reply 

i got your problem of ip address on second port as they will overlap so in this case you can connect the second switch to the first switch and configure the connecting port as trunk that will solve your problem. 

[Richard Burts · Accepted solution]

The original poster asks is it the router or is it me? And the answer is that really it is the router. What you are trying to do is implementing Integrated Routing and Bridging which uses Bridged Virtual Interface (BVI).  ASR does not support that and wants you to use Bridge Domain Interface to accomplish the same function. I hope this link will provide information that you will find useful

https://www.cisco.com/c/en/us/td/docs/routers/asr1000/configuration/guide/chassis/bdi.html

[Mark3205]

Hi Rick,

Thanks for pointing me in the right direction.

I now have everything set and it works as described in the document.

Kind regards

Mark

[Richard Burts]

Mark

You are welcome. I am glad that my suggestion was helpful. Thank you for marking this question as solved. This will help other participants in the community to identify discussions which have helpful information. This community is an excellent place to ask questions and to learn about networking. I hope to see you continue to be active in the community.