[Ethereal-users] looking for virus or spamming

["Jon Miller" <jlmiller@xxxxxxxxxxxxxxxxxx>]

I'm currently looking at a gateway server that seems to have a awful lot of DNS requests and ARP requests.  Not sure if this is correct, but is there a way to home in on virus and spam checking?  I eliminate all valid traffic, but I would like to know if there are certain packets I can look for.  I know this is huge area, if there is something I can look for trim the search I would appreciate it. 

Thanks

Jon