All, The Kawasaki LSI USB Ethernet driver was causing a crash in ipt_do_table() on mips because the address fields in the IP header were not word aligned. Many (all?) other ethernet drivers do an skb_reserve of 2 to word align the address fields, and doing this in kaweth.c fixed my crash. kernel: 2.4.17 hardware: Netgear EA101 USB Ethernet Quinn