%IP-4-DUPADDR error message

trinawong · ‎04-28-2008

Dear All,

There are error messages flood with '%IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676'. The Duplicate ip address 10.10.10.3 is the virtual ip address of RouterA, could you please advise why the error message show up and why the virtual ip address has two different mac address on different router. thanks a lot!

Apr 29 04:11:33: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:12:03: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:12:33: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:13:04: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:26:14: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:26:44: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:27:15: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

Apr 29 04:27:45: %IP-4-DUPADDR: Duplicate address 10.10.10.3 on FastEthernet0/0, sourced by 0009.6b62.1676

RouterA#

RouterA#sh clo

04:40:24.651 GMT Tue Apr 29 2008

RouterA#sh arp | i 0009.6b62.1676

Internet 10.10.10.201 0 0009.6b62.1676 ARPA FastEthernet0/0

Internet 10.10.10.150 0 0009.6b62.1676 ARPA FastEthernet0/0

Internet 10.10.10.183 0 0009.6b62.1676 ARPA FastEthernet0/0

Internet 10.10.10.190 0 0009.6b62.1676 ARPA FastEthernet0/0

Internet 10.10.10.168 0 0009.6b62.1676 ARPA FastEthernet0/0

Internet 10.10.10.35 1 0009.6b62.1676 ARPA FastEthernet0/0

RouterA#sh run int fa0/0

Building configuration...

Current configuration : 320 bytes

!

interface FastEthernet0/0

description Customer LAN

ip address 10.10.10.251 255.255.255.0

load-interval 30

duplex auto

speed auto

no cdp enable

glbp 10 ip 10.10.10.3

glbp 10 weighting 100 lower 91 upper 99

glbp 10 weighting track 1

end

Thank you.

Goutam Sanyal · ‎04-28-2008

Hi, As per Cisco "Another system is using your IP address.

Recommended Action: Change the IP address of one of the two systems"

Also requesting you to check the "HSRP/GLPB" configuration, if its configured.

Thanks

Goutam

Pls rate if t helps you

trinawong · ‎04-28-2008

Thanks for your reply.

From the 'show arp', can see different ip addresses share one mac address, it's not normal, seems to me like ARP attack, do you have any experience to deal with this kind of problem?

Thank you,

Goutam Sanyal · ‎04-28-2008

Hi, Previously at the time of deploying the "HSRP" we have faced the same problem. That time we found a switching loop at our network with our management VLAN. So check your VLAN configuration as well as STP status of your switch fabric. As well as check any switching loop as present or not. Thanks Goutam (Pls rate if I am informative)

smothuku · ‎04-28-2008

Hi ,

Can you claer CAM table using clear mac-address-table dynamic command ...Check the issue after clearing the CAM.

Thnaks,

Satish