Hello guys not sure about this one really I appear on the face of it I may have an issue with my 2600plus.

Router = 10.0.0.1
my pc = 10.0.0.100

I have been practising using a network monitor piece of software and i keep getting ARP broadcasts from the router who has 10.0.0.100 then my computer replies with 100 is at blah blah which is as it should be, and if you go to the arp cache table you can see the router knows my computer IP address.

But the router keeps insisting on broadcasting for my address.

My understanding of arp is you get the broadcast then if a response is heard the device adds it to their arp cache table then shuts up.

Can anyone shed light on this ????

Thanks very much

I think your understanding is correct. A device will send out an ARP broadcast to a local subnet in order to determine the MAC address of a host on that network segment it wants to communication with. If a response is received, the ARP entry is normally put in an ARP cache on the initiating device. Entries are removed from the ARP cache when they age out through either inactivity or reach a timeout value set on the device.

This may just be that the time out period on the Draytek arp cache is extremely short.

but its like constant i mean i have an entry from the router asking who is at 101 tell router ip address it gets an answer in milliseconds then about a minute later its repeating itself.

I did have even more arp traffic asking who has an address that doesnt even exist on the network I found out what was causing this by going through the menus on the router it was due to Syslog being enabled and not pointing to the correct IP address but there doesn't seem to be anything else that makes sense to be causing this.

It's not a huge problem I just want to know why it is doing it and if I can shut it up coz there is no reason for it to be chatting away like that.

I know this is a bit of an old thread, but I noticed all the arp traffic from my 2800 and 2600 and had a look at the routers in telnet.

There is an option to set the lifetime of the arp cache entries in the telnet menu on the 2800 but not the 2600+

type ip arp setCacheLife ?

Default seems to be about 180 seconds?