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Catalyst 2924 EN XL Trunking Question + Linkflap

Hello, just had a bit of a chat with a friend of mine who's ccna / ccnp. The problem i asked him about is the connectivity between my Netopia 3351 and my catalyst 2924. When i start sending packets from the cisco to the gw (netopia) the link goes up and down, and dont work very well. (linkflap)

The first thing he said was that netopia and cisco dont talk very well with each other. The second thing he said was that i should trunk the port on the cisco, but not with ISL. I dont know what ISL mean, but shouldnt trunking be done on both devices if its going to work ? (Could this be a workaround for the problem thats not really "allowed" method? )

Can anyone help me? Translate my friends advice to something that makes sense?

Anyone else had problems with netopia and cisco together?

And, while im allready posting, can someone help me with the url for newest IOS for c2924 EN XL, if its not too much trouble? :)

Mega Thanks!



Re: Catalyst 2924 EN XL Trunking Question + Linkflap


I don't know Netopia products but some general advices for connecting Cisco to other vendors devices:

1)Don't use trunks unless it's absolutely necessary. There might be big troubles with trunking.

2)If you have to use trunks, don't use ISL. It's Cisco proprietary and other vendors don't support it.

Use a standard 802.1q encapsulation instead of ISL.

See for some details.

3) When configuring 802.1q encapsulation, be careful about native VLAN.

Cisco is using VLAN1 as default native VLAN (untagged) on 802.1q trunks. Other vendors might not use native VLAN at all, or you have to configure it manually.

4)Link to newest Cat2924XL IOS: (you need a CCO login).



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