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New Member

DLSw using ethernet, switch and redundancy

Hi everyone, I hope someone can help me with this one, altough I know its a very specific and somewhat uncommon doubt:

Im trying to get redundancy using two DSLw routers serving some hosts using SNA. Imagine this scenario:

From left to right: An SNA host connecting to a ethernet switch. From that switch two ports connect to two different DLSw routers. Both of the routers connect to a big ISP cloud and from the cloud we have a remote DLSw router with some SNA hots.

As you can see (or imagine i hope), from the left host (the one behind the switch) has 2 different paths to reach the host in the very right (one trough each router).

I know there are some issuses in this kind of scenario, because from the perspective of the sw there could be two ports with the same MAC address (the MAC address of the right SNA host and the two ports of the DLSw routers).

The thing is here and my doubt is here: If one of the routers fail (the one which is serving the left host), the other DLSw router cannot serve the left host until the MAC entry of the switch ages out and then after being flooded learned again in the other switch port (the port that connects to the working DLSw router). Is that correct? And if that is the case, can I solve the "problem" reducing the timer in the switch in order to age the MAC Table more quickly?

Thanks in advance, any direction wolud be very helpful! And sorry for my english mistakes, its not my native language.

New Member

Re: DLSw using ethernet, switch and redundancy

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