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New Member

Switch and Router duplex mode

We have Cisco 2600 with half duplex mode setting while we plan to have a switch with full duplex mode.

How to set Cisco router to have full duplex mode?

Another question:

When we plan to change IP address for the whole class C range, what is the best way to do so (considering the router is for Internet connection and lan gateway)? No change on Internet ISP connection side.

Very appreciated.


  • Other Network Infrastructure Subjects
New Member

Re: Switch and Router duplex mode

Not all of Cisco routers are able to switch to full duplex. The easiest way to tell is to get in enable mode, then config-if mode and use the ?. If your router can be placed in full duplex you will see the command there. If not then you can't. Be aware that I once saw the command full-duplex using the ? on a 2610 router which although did enter full-duplex in the config, did not work. Turn on logging buffered and check the log for duplex mismatch messages to be sure.


New Member

Re: Switch and Router duplex mode


If your ethernetport is 10base-T it's impossible to set the interface to full-duplex. If you have a 100base-T then you can set the interface to full-duplex.

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