Gateway IP Duplicated

[caioamonteiro]

Hi,

We have our network segmented in VLANs, and at one branch office, we had some problems cause someone used the gateway IP in a device. We use as gateway a Cisco Catalyst 3560-G 24T-S IOS 12.2(58)SE2.

I would like to know if I have some way to block this making some config on switch to not let a device joins the network with gateway IP.

Thanks,

Caio.

[cadet alain]

Hi,

You can use IP source guard with or without DHCP snooping.

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_52_se/configuration/guide/swdhcp82.html

Regards.

Alain.