I can ping ipv6 hosts from the router, but when i start radvd and all clients gets their addresses then i can't ping the router, even with firewall disabled. Some tests i've done: # the client [~]$ uname -a Linux raver 2.6.21.5 #10 SMP PREEMPT Mon Jun 18 11:39:35 CEST 2007 x86_64 GNU/Linux [~]$ ip -6 addr 1: lo: <LOOPBACK,UP,10000> mtu 16436 inet6 ::1/128 scope host valid_lft forever preferred_lft forever 5: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qlen 1000 inet6 2001:1418:160:0:20d:29ff:fe4f:cbe/64 scope global dynamic valid_lft 2591780sec preferred_lft 604580sec inet6 fe80::20d:29ff:fe4f:cbe/64 scope link valid_lft forever preferred_lft forever [~]$ ip -6 route 2001:1418:160::/64 dev eth0 proto kernel metric 256 expires 2591937sec mtu 1500 advmss 1440 hoplimit 4294967295 fe80::/64 dev eth0 metric 256 expires 21333200sec mtu 1500 advmss 1440 hoplimit 4294967295 ff00::/8 dev eth0 metric 256 expires 21333200sec mtu 1500 advmss 1440 hoplimit 4294967295 default via fe80::213:10ff:fe01:c52a dev eth0 proto kernel metric 1024 expires 1575sec mtu 1500 advmss 1440 hoplimit 64 # the router [/]# uname -a Linux OpenWrt 2.6.21.5 #13 Fri Jun 22 01:12:22 CEST 2007 mips unknown [/]# ip -6 addr 1: lo: <LOOPBACK,UP,10000> mtu 16436 inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qlen 1000 inet6 2001:1418:160::1/64 scope global valid_lft forever preferred_lft forever inet6 fe80::213:10ff:fe01:c52a/64 scope link valid_lft forever preferred_lft forever 6: sixxs@NONE: <POINTOPOINT,NOARP,UP,10000> mtu 1280 inet6 2001:1418:100:a5::2/64 scope global valid_lft forever preferred_lft forever inet6 fe80::5231:3e3b/64 scope link valid_lft forever preferred_lft forever inet6 fe80::c0a8:1/64 scope link valid_lft forever preferred_lft forever [/]# ip -6 route 2001:1418:100:a5::/64 via :: dev sixxs metric 256 expires 42880940sec 2001:1418:160::/64 dev eth0 metric 256 expires 42880901sec fe80::/64 dev eth0 metric 256 expires 42880902sec fe80::/64 via :: dev sixxs metric 256 expires 42880941sec ff00::/8 dev eth0 metric 256 expires 42880902sec ff00::/8 dev sixxs metric 256 expires 42880941sec default via 2001:1418:100:a5::1 dev sixxs metric 1024 expires 42880941sec unreachable default dev lo metric -1 error -128 # ping6 from the client while dumping traffic on the router [~]$ ping6 -c1 2001:1418:160::1 PING 2001:1418:160::1(2001:1418:160::1) 56 data bytes From 2001:1418:160::1 icmp_seq=1 Destination unreachable: Address unreachable --- 2001:1418:160::1 ping statistics --- 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms [/]# tcpdump -n ip6 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 09:24:42.170772 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > ff02::1:ff00:1: ICMP6, neighbor solicitation, who has 2001:1418:160::1, length 32 09:24:42.359939 IP6 2001:1418:160::1 > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, neighbor advertisement, tgt is 2001:1418:160::1, length 32 09:24:42.172267 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > 2001:1418:160::1: ICMP6, echo request, seq 1, length 64 09:24:42.172753 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, redirect, 2001:1418:160::1 to 2001:1418:160::1, length 152 09:24:42.174771 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff00:1: ICMP6, neighbor solicitation, who has 2001:1418:160::1, length 32 09:24:43.174664 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff00:1: ICMP6, neighbor solicitation, who has 2001:1418:160::1, length 32 09:24:44.174715 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff00:1: ICMP6, neighbor solicitation, who has 2001:1418:160::1, length 32 09:24:45.174723 IP6 2001:1418:160::1 > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, destination unreachable[|icmp6] 09:24:47.164692 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:47.170023 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 24 09:24:47.170449 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:24:47.174773 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:24:48.164693 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:48.167953 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 24 09:24:48.168201 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:24:48.174728 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:24:49.164638 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:49.166594 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 24 09:24:49.166842 IP6 fe80::213:10ff:fe01:c52a > 2001:1418:160:0:20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:24:49.174734 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:24:50.184732 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:50.510712 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:50.514854 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:24:51.184671 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:51.187468 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:51.514678 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:24:52.184659 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:52.186516 IP6 2001:1418:160:0:20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is 2001:1418:160:0:20d:29ff:fe4f:cbe, length 32 09:24:52.514724 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:25:35.038757 IP6 fe80::213:10ff:fe01:c52a > ff02::1: ICMP6, router advertisement, length 80 30 packets captured 60 packets received by filter 0 packets dropped by kernel # same thing but with link addresses [~]$ ping6 -c1 -I eth0 fe80::213:10ff:fe01:c52a PING fe80::213:10ff:fe01:c52a(fe80::213:10ff:fe01:c52a) from fe80::20d:29ff:fe4f:cbe eth0: 56 data bytes From fe80::213:10ff:fe01:c52a icmp_seq=1 Destination unreachable: Address unreachable --- fe80::213:10ff:fe01:c52a ping statistics --- 1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms [/]# tcpdump -n ip6 tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes 09:28:21.081758 IP6 fe80::20d:29ff:fe4f:cbe > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:21.083492 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, neighbor advertisement, tgt is fe80::213:10ff:fe01:c52a, length 32 09:28:21.084629 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, echo request, seq 1, length 64 09:28:21.084983 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 152 09:28:21.094723 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:22.094669 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:23.094664 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:24.094710 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, destination unreachable[|icmp6] 09:28:26.074671 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:26.078375 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 24 09:28:26.078693 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:28:26.084732 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:27.074692 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:27.079983 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 24 09:28:27.080230 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:28:27.084766 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:28.074642 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:28.076157 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 24 09:28:28.076398 IP6 fe80::213:10ff:fe01:c52a > fe80::20d:29ff:fe4f:cbe: ICMP6, redirect, fe80::213:10ff:fe01:c52a to fe80::213:10ff:fe01:c52a, length 112 09:28:28.084715 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:29.094676 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:29.096620 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 32 09:28:29.104730 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:30.094702 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:30.097773 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 32 09:28:30.104713 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:31.094726 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff4f:cbe: ICMP6, neighbor solicitation, who has fe80::20d:29ff:fe4f:cbe, length 32 09:28:31.104731 IP6 fe80::213:10ff:fe01:c52a > ff02::1:ff01:c52a: ICMP6, neighbor solicitation, who has fe80::213:10ff:fe01:c52a, length 32 09:28:31.391335 IP6 fe80::20d:29ff:fe4f:cbe > fe80::213:10ff:fe01:c52a: ICMP6, neighbor advertisement, tgt is fe80::20d:29ff:fe4f:cbe, length 32 29 packets captured 61 packets received by filter 0 packets dropped by kernel Cheers, Matteo