Excessive ARP requests?

[PiKe]

I have HG633 router which seems to be broadcasting a lot of ARP requests and causing network activity of every port of my switch, when the router is unplugged the activity stops.

The router isn't doing DHCP so shouldn't be sending out ARP requests in any kind of volume, is the router broken or is there a loop in my network somewhere? Can I detect a loop with software?

I have unplugged each switch port one-by-one and the activity only stops once the up-link to the router is removed from the switch.

 

[ChrisD.]

If the MAC address of a device talking to the internet has dropped out of the HG633's CAM table it'll do an ARP to find the physical address of said device.

 

[PiKe]

If the MAC address of a device talking to the internet has dropped out of the HG633's CAM table it'll do an ARP to find the physical address of said device.

It's constant though, 40 packets a second to all different addresses.

 

[ChrisD.]

What are you using to monitor the requests?

 

[PiKe]

What are you using to monitor the requests?

Wireshark.

I can see the port lights constantly flashing on every device thats plugged in too.

 

[ChrisD.]

If you plug the device doing wireshark into a switch which is connected to only that device and the router, does it do it?

 

[PiKe]

Yes if this machine is the only device plugged in it still is sending out loads of ARP requests.

 

[ChrisD.]

Odd, anything in the menu system of it? I'm not familiar with the device at all, but most ISP provided ones are rubbish.