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Question about 3524xl and ARP wigging out

I have 2 switches connected by cat 5 and one 3745 also connected to the 2 switches. Now, what happens is I can ping an ip phone on the LAN, and then all of a sudden I can't. It just "dissapears"! If I go to the switch that the phone is connected to and do a "clear arp-cache" I can ping the phone again. This seems to happen every hour or so.

Any ideas?

Thanks,

Geoff

5 REPLIES
New Member

Re: Question about 3524xl and ARP wigging out

Geoff,

Without being there to troubleshoot, it seems as though you have a mac or ip address conflict. The symptoms you describe point to these. R U assigning macs or using the BIAs? How are you assigning IPs? Statically? DHCP?

-Bo

Bronze

Re: Question about 3524xl and ARP wigging out

Bo,

I am using DHCP, and I have not gotten an IP conflict on any PCs or Phones, but that is not to say there are none.

What would be the best way to find out?

Geoff

Bronze

Re: Question about 3524xl and ARP wigging out

The arp cache shouldn't matter to the switch unless it is layer 3 switching. In that case look at the cache first and see if the mac address is correct for the phone that should have the ip address. If not, figure out what device has the mac that is in the arp entry.

New Member

Re: Question about 3524xl and ARP wigging out

Geoff,

Are you having problems with just one phone in particular, or multiple phones on a specific subnet, or all devices in the network?

-Bo

Bronze

Re: Question about 3524xl and ARP wigging out

BO,

Thanks for replying, I located the problem. An old router was hooked up to the LAN (by my "new guy", he needs a little work). He was going through and testing old equipment we are selling and forgot to take it down. I got a message on our 3745 duplicate ip, and I knew something was fishy!!

Thanks,

Geoff

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