I have currently 4 Linux machines in my network, one embedded system running Linux-2.4.20, a system build from scractch over the last 13 years running 2.4.34.2 and two Debian boxes, both running Debian's Linux kernel 2.6.18-4-686.
When I ping to the broacast address or the allhosts multicast address I get replies from the embedded and the self-built sysem, but not from the two Debian boxes: janus:urs$ ping -w2 10.0.0.255 PING 10.0.0.255 (10.0.0.255): 56 octets data 64 octets from 10.0.0.1: icmp_seq=0 ttl=64 time=0.2 ms 64 octets from 10.0.0.31: icmp_seq=0 ttl=64 time=0.7 ms (DUP!) 64 octets from 10.0.0.1: icmp_seq=1 ttl=64 time=0.1 ms 64 octets from 10.0.0.31: icmp_seq=1 ttl=64 time=0.6 ms (DUP!) --- 10.0.0.255 ping statistics --- 2 packets transmitted, 2 packets received, +2 duplicates, 0% packet loss round-trip min/avg/max = 0.1/0.4/0.7 ms janus:urs$ ping -w2 224.0.0.1 PING 224.0.0.1 (224.0.0.1): 56 octets data 64 octets from 10.0.0.1: icmp_seq=0 ttl=64 time=0.3 ms 64 octets from 10.0.0.31: icmp_seq=0 ttl=64 time=0.9 ms (DUP!) 64 octets from 10.0.0.1: icmp_seq=1 ttl=64 time=0.1 ms 64 octets from 10.0.0.31: icmp_seq=1 ttl=64 time=0.6 ms (DUP!) --- 224.0.0.1 ping statistics --- 2 packets transmitted, 2 packets received, +2 duplicates, 0% packet loss round-trip min/avg/max = 0.1/0.4/0.9 ms The two Debian machines do reply to unicast pings, however: janus:urs$ ping -c1 blue PING blue.isnogud.escape.de (10.0.0.2): 56 octets data 64 octets from 10.0.0.2: icmp_seq=0 ttl=64 time=1.6 ms --- blue.isnogud.escape.de ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max = 1.6/1.6/1.6 ms janus:urs$ ping -c1 mop PING mop.isnogud.escape.de (10.0.0.65): 56 octets data 64 octets from 10.0.0.65: icmp_seq=0 ttl=64 time=0.3 ms --- mop.isnogud.escape.de ping statistics --- 1 packets transmitted, 1 packets received, 0% packet loss round-trip min/avg/max = 0.3/0.3/0.3 ms Also, I have written two small test programs, udp-ping and udp-echo, which send short packets two a specified UDP port and echo all packets to a certain UDP port, respectively. If I send UDP packets to the multicast address, udp-echo will answer, also on the Debian machines. This shows that the Debian machines are able to receive multicast. So what is the reason, that the 2.6.18-4-686 kernel does not reply to ICMP echo request to broadcast and multicast address? I've looked through /proc/net and /proc/sys/net but haven't found anything which looked relevant. urs -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]