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How to disable dynamic address learning on Catalyst 2950 switch and ...

We have Catalyst WS-C2950-24 switch running under IOS Version 12.1(9)EA1, standard image.

What we need:

1. Disable dynamic MAC address learning. We need for the switch not to discard frames with previously learned MACs. Or, if possible, disable any MAC address filtering.

2. Turn off transmitting any service frames from the switch itself (like STP frames, trunk negotiating, etc.). We can turn off all types of frames going from the switch except for the frames of following format:

{DestinationAddress=SwitchPort MAC, SourceAddress=SwitchPort MAC, etc. } with length=64 including CRC. What are these frames for and how can we turn them off?

3. Can we make up port-based VLANs without using 802.1Q tags and VIDs? Is it possible to define port-to-port permission mask for creating vlans without 802.1Q tag and vid analysing, filtering, inserting and replacing.


Re: How to disable dynamic address learning on Catalyst 2950 swi

Since there has been no response to your post, it appears to be either too complex or too rare an issue for other forum members to assist you. If you don't get a suitable response to your post, you may wish to review our resources at the online Technical Assistance Center ( or speak with a TAC engineer. You can open a TAC case online at

If anyone else in the forum has some advice, please reply to this thread.

Thank you for posting.