Gratuitous ARPclarification

[bobc20101]

We were recently setting up an application where the client PC requires a static IP address. After several reboots of the PC it was reporting duplicate IP address or the IP address would be changed to something other than the original static IP address. When Gratuitous ARP was disabled the static IP address is retained across 5 plus reboots.  The PC is running Windows 7 Embedded.

We have set up this application in many other environments and have not encountered this issue.

Question: was the address reset being issued by the router or other network device or was this a result of some other network function? In other words what is the source of this behavior?

Any guidance is appreciated.

[TIM JUDGE]

Was your IP address statically entered in the O/S or was the address reserved in DHCP for your MAC address on your behalf?

Yes, there could be more than one DHCP server serving the same range (perhaps a backup DHCP server has become active or perhaps they are supposed to have an address allocation each but the address ranges overlap.)

Or... if you have setup a static entry on your PC in the O/S but the address is part of a DHCP subnet range then that would explain the conflict as some other PC may have got your address if your PC was offline at the time and then later on you boot the PC to find someone else has got your address. In this case, just setup a DHCP reservation with your MAC address

It depends on your installation.

All the best

[Peter Koltl]

The switch may be using device tracking. Check these articles:

Duplicate IP Address 0.0.0.0. Error Message Troubleshoot

IPDT Overview

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