In article <7F17177AC9AC2F4CB4A1A33C936D038D0AC18B@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx> you wrote: > I am having some trouble in understanding the linux arp cache behavior. some older documentation can be found in arp.7. For example there is base_readable_time and the gc_tresh1 you already found. This also depends on kernel versions, I think. And possibly also if you look at gateway or host entries (because of FIB cache references) I think it also helps to force an arp lookup to kick in the cleanup (ping a not cached local ip). On some higher level errors some entries are flushed, too (ping a non existing local ip). Greetings Bernd - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html