different ways of configuring bridging

[jadroer]

Hi,

I have two questions regarding bridging configuration.

1) Let's suppose I want a router just bridge IP but not route it. I just have to create one or more bridge groups and then link to them the desired interfaces. But to let all work I have to do something more, and here I have two possibilities.

.- disable ip routing with the command -no ip routing-

.- keep ip routing enabled (by default) and enable -bridge irb-

in both cases it works, and it seems the behaviour is the same, but there's any difference taking into account that, for IP, I just want to bridge?

2) If I want a router to make bridging and routing at the same time, but keeping the two processes separate (that is, not using BVI) cisco manuals recomend to use concurrent routing and bridging with the command -bridge crb-, but if I use integrated routing and bridging -bridge irb- I still have the same network behaviour.

And the question is again, is there any difference in configuring one way or another?

thanks in advance,

Joan

[milan.kulik]

Hi,

1) I think that disabling IP routing should decrease your router CPU and memory load.

2) While using IRB you are able to bridge AND route IP at the same time on one interface (i.e. bridge IP inside one bridging group and route IP outside it). Using CRB you can route OR bridge IP on one particular interface.

Regards,

Milan

[jadroer]

Thanks for your quick response.

Regarding the second question. As you say, Using CRB you can route OR bridge IP on one particular interface, but working in this model, you can change the command bridge crb for bridge irb, leaving the rest of the configuration untouched, and the net works as well.

I suppose there is also a matter of CPU load as irb has more functionalities.

regards,

Joan