[Firestarter-user] ARP DoS??

[Darkman <da...@cl...>]

in the past 2 days I have had somethign weird happening, and am =
wondering if its a DoS on my server. it has caused mail to not be =
delivered,a dn DNS not to work and any connection to the Inet has halted =
completely. the only way to restore service is to reboot the server and =
all is fine, except int he past two days it starts up again after a =
wihle. the first thign I notice, is lack of email, then I look at my =
switch lights, and see the light for the external NIC, on the switch is =
flashing insanely. no other lights are doing this. only the light ont he =
switch that leads to the external NIC card which is managed by =
firestarter.
I have sbc dsl which comes in thru their modem, then into a switcha nd =
is broken up to go to different servers, then one of them goes to my =
firestarter box, and that in turn goes out to an internal switch via a =
second nic. so the box is multi homed. once I reboot the machine all is =
fine, then it will start up again at any time. I am not seeing anythign =
logged my firestarter, nor do I see anything by tail-f /var/log/messages
but when I run ethereal I do see some things. I see arp requests. namely =
they say they are coming from the external NIC on the firestarter =
machien to the broadcast number(?), it says broadcast int he interface, =
and it is asking who is 66.122.250.xxx. it also asks about one other =
address, the first address is an IP address in the subnet assigned to =
me, I have 5 IPS that they gave me, and the one that its asking about, =
is one of mine, but its not in use......which is why I think its a DoS, =
because who would be needing to know who that IP address is, especially =
my own machine? what can I do short of rebooting frequently or =
reassigning the IP address ont he machine to one of my other IP =
addresses?