Hi all, I have a virtual firewall with 4 ports, eth[0-3] It stopped responding to ARP requests on one of the ports, eth3. Hosts would try to ping the machine, running tcpdump on the machine I would see the ARP "who-has" requests coming in but no answers going back. I tried pinging out to a host on that port and got no reply. tcpdump showed no packet going out. Traceroute gives an error "No buffer space available": # traceroute -n 192.168.1.79 traceroute to 192.168.1.79 (192.168.1.79), 30 hops max, 60 byte packets send probe: No buffer space available and arping gives a similar error: # arping -s ab:cd:ef:12:34:56 -i eth3 192.168.1.79 ARPING 192.168.1.79 arping: libnet_write(): libnet_write_link(): only -1 bytes written (No buffer space available) I tried putting the interface down and up again: ifdown eth3 ifup eth3 and restarting shorewall but it didn't help. Finally, after rebooting the virtual firewall box it worked again. It had been running for 253 days before the reboot. Looking in Google I found various other people had seen the "No buffer space available" error and some had to reboot each time. It is a standard Debian kernel: Linux myhost 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64 GNU/Linux Can anybody comment on further troubleshooting steps if I see this problem again? Regards, Daniel ------------------------------------------------------------------------------ Infragistics Professional Build stunning WinForms apps today! Reboot your WinForms applications with our WinForms controls. Build a bridge from your legacy apps to the future. http://pubads.g.doubleclick.net/gampad/clk?id=153845071&iu=/4140/ostg.clktrk