A huge thank you to all who offered advice on my network problem. It appears that the problem has been fixed by changing hostname.sis0 from "dhcp NONE NONE NONE" to "dhcp media 10baseT".
Previous output from ifconfig showed: sis0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 media: Ethernet autoselect (100baseTX full-duplex) It now shows: sis0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500 media: Ethernet 10baseT I guess it was a stupid autonegotiation problem after all. I didn't know that could affect traffic in only 1 direction. Live and learn :) At this point I have reloaded my full pf rule set. Unless doing so introduces a new problem I believe things are fine. The advice I received from the list has been educational and much appreciated as always. RPK.