Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

DHCP duplicate address error

Hi all

I m running DHCP server in one of our 7200 series router which started giving error logs recently after we added some static NAT statements.

I am attaching the config and also the error log

no ip dhcp conflict logging

ip dhcp excluded-address Y.Y.Y.250 Y.Y.Y.254

ip dhcp ping packets 5


ip dhcp pool interanet

network Y.Y.Y.0

dns-server X.X.X.70 X.X.Z.70

default-router Y.Y.Y.254

lease infinite

ip nat pool internet X.X.X.10 X.X.X.10 netmask

ip nat inside source list 1 pool internet overload

ip nat inside source static tcp Y.Y.Y.252 8080 X.X.X.9 8080 extendable

ip nat inside source static tcp Y.Y.Y.253 1968 X.X.X.60 1968 extendable

ip nat outside source static tcp X.X.X.9 8080 Y.Y.Y.252 8080 extendable

ip nat outside source static tcp X.X.X.60 1968 Y.Y.Y.253 1968 extendable

Aug 5 17:13:46.737 IST: %IP-4-DUPADDR: Duplicate address Y.Y.Y.253 on FastEthernet4/1, sourced by 0004.7673.6418

IOS version :

Cisco Internetwork Operating System Software

IOS (tm) 7200 Software (C7200-JS56I-M), Version 12.1(8a), RELEASE SOFTWARE (fc1)

Copyright (c) 1986-2001 by cisco Systems, Inc.

Compiled Wed 23-May-01 01:49 by yiyan

Image text-base: 0x60008950, data-base: 0x61B54000

is it reqd to hv both inside and outside statements for Static NAT ??

Pls helpe me to avoid getting the error logs ..




Re: DHCP duplicate address error

Hi Prem,

This is commonly associated with HSRP but the problem is usually not with HSRP but network congestion or a misconfiguration on a switch link. From your commnets I think you just have two devices there with the same IP address configured on them. Normally if there is a problem with an HSRP duplicate you will see this message: %STANDBY-3-DUPADDR. See if you can locate a station that might have this address which might be conflicting with a physical or HSRP addresss on the router.