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New Member

trunking between cat 4003 and cat 3548/2924

i have a catylast 4003 that has a "piggybacked" catalyst 3548 on one port. this has been working fine until yesterday. i got a message that this 3548 was down. both devices showed connectivity, but i could not get the 3548 to work. logged onto console port and there were no errors evident. i reconfigured another port on the 4000 with no success. i installed a known working 2924 on this newly configured port. i can now "see" the 2924, can telnet to it, access the web interface, make configuration changes,etc. not one device connected to the 2924 can access the network, nor can i see any of these devices. counters on the individual ports show activity. i can reset them, they clear, and continue to show activity. does anyone have an idea what is up? thanks in advance

  • Other Network Infrastructure Subjects
New Member

Re: trunking between cat 4003 and cat 3548/2924


Are there any VLAN's configured on the new 2924 Switch ? If so are there any trunks links configured ?

Is VTP active ? if so check the config-revision on the Cat2924 (It might be higher that that of Cat4003) if so try to reset the VTP revision No. (remove the switch from VTP domain and add it again).

Just a thought.


New Member

Re: trunking between cat 4003 and cat 3548/2924

1. There may also be an issue with the trunking between the ports. Cisco has proprietary ISL trunking, but the cat4003 uses 802.1q trunking (the Open Standard form). The other devices use one or the other, but I believe that the 4000 is limited to 802.1q.

2. They don't mix and match.