ARP problem

[Mober]

All my XP machines in my AD domain will not cache any other arp's in the domain. Currently I have alot of ARP broadcasts going on, and when I check my XP machines in the command line the only ARP registered are my two servers and default gateway. How do I get my machines to begain caching the ARP requests? Thanks.

 

[victorv]

hi,
probably you know what I will write, but this is a forum;

when from machineA you request to comunicate with machineB
(ie ping host2), using DNS or file hosts or (+/-) wins,
there is a translation between name and IP-ADDERSS.
(As you given ping 192.168.1.100)

Then the machineA send a broadcast with the ARP request:
if your networkmask is 255.255.255.0, the packet will be
ARPREQ arg=192.168.1.100 send=yourip dest=192.168.1.255
If destaddr is in yout network (192.168.1.0), this will
answer with an ARPRSP sending its macaddress.

Your PC stores it in its arp cache (what you see by arp -a)
and from that moment, use directely the mac-addr to get services. The cache has own policy and if you dont use the row for a time or operations it will be deleted.

To avoid this you may "preload" using arp -s ip.add mac-add
This row will be static.

Using scripts on login, you need to know:
- mac-adderss of your PCs
- know who usually speak with other
- maintain all this

If there are a lot of ARP request, it means tha "all" speak
with "everybody" : you have to preload a lot of rows
and probably the cache may be not enough .

Worth it ?

bye
vic

 

[Mober]

Thanks I'll load the arps into my switchs, that should help.