Loosing network connection, wrong arp entry

[felix27]

I have a windows 2003 server used for exchange enterprise edt.

Sometimes i loose the connection to the server from different clients. (ping request timed out.)
After replacing all the network parts. (Switches, Cables,Nic...) i found the following:

at the moment, i loose the connection, my client shows a wrong entry in the arp-table. It shows the IP-address of the server with a wrong mac-address. (the mac-address of the inside interface of my firewall).

after some minutes, the arp entry is deleted and the correct entry is made. after that everything works fine until the next breakdown.

Since i have changed all the network parts, there seems to be a problem with the OS??

I don´t know what to do, to solve my problem.

Help appreciated. ;o)

 

[felix27]

We found a solution for this problem.

There was a nat-entry on the firewall which redirect to the address of the exchange server (for Outlook Web Access).

We disabled the "proxy arp" function on the inside Interface of our firewall.

Now everything works. no more broadcasts with the wrong mac-address.

kind regards,

felix