I am reproducing this on a local IPv6-enabled network, setting my global IPv6 address automatically using router advertisements. I don't yet know whether this is strictly related to autoconf or not, but I can test it if required. Steps to reproduce: 1) Acquire IPv6 address through SLAAC (I'm currently using NetworkManager but this is done in kernel anyway) 2) View your own IP address and try to ping6 it. It should work. 3) ip link set lo down 4) ip link set lo up 5) Try pinging your global IPv6 address again. Expected results: #5 should work, just like #2 did Actual results: #5 doesn't work, ping gives no feedback about what happened Notes: Testing it with firewall enabled or disabled, it doesn't make a difference.
Pinging ::1 works, though.
Tested with kernel 3.6.7-4.fc17.x86_64
can you please provide output of "ip a" in state 2), 3), 4) ? Thanks.
This bug is being closed with INSUFFICIENT_DATA as there has not been a response in 2 weeks. If you are still experiencing this issue, please reopen and attach the relevant data from the latest kernel you are running and any data that might have been requested previously.
Output of 'ip address', I'm afraid it won't help much, though, as the problem is most probably internal to the kernel. 2) 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000 link/ether 00:1d:72:88:56:36 brd ff:ff:ff:ff:ff:ff inet6 fe80::21d:72ff:fe88:5636/64 scope link valid_lft forever preferred_lft forever 3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1f:3c:1b:9e:5e brd ff:ff:ff:ff:ff:ff inet 84.246.161.89/28 brd 84.246.161.95 scope global wlan0 inet6 2a00:1268:1ff:f001:21f:3cff:fe1b:9e5e/64 scope global dynamic valid_lft 86396sec preferred_lft 14396sec inet6 fe80::21f:3cff:fe1b:9e5e/64 scope link valid_lft forever preferred_lft forever 704: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1360 qdisc pfifo_fast state UNKNOWN qlen 100 link/none inet 10.36.116.23/22 brd 10.36.119.255 scope global tun0 3) 1: lo: <LOOPBACK> mtu 65536 qdisc noqueue state DOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000 link/ether 00:1d:72:88:56:36 brd ff:ff:ff:ff:ff:ff inet6 fe80::21d:72ff:fe88:5636/64 scope link valid_lft forever preferred_lft forever 3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1f:3c:1b:9e:5e brd ff:ff:ff:ff:ff:ff inet 84.246.161.89/28 brd 84.246.161.95 scope global wlan0 inet6 2a00:1268:1ff:f001:21f:3cff:fe1b:9e5e/64 scope global dynamic valid_lft 86394sec preferred_lft 14394sec inet6 fe80::21f:3cff:fe1b:9e5e/64 scope link valid_lft forever preferred_lft forever 704: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1360 qdisc pfifo_fast state UNKNOWN qlen 100 link/none inet 10.36.116.23/22 brd 10.36.119.255 scope global tun0 4) 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN qlen 1000 link/ether 00:1d:72:88:56:36 brd ff:ff:ff:ff:ff:ff inet6 fe80::21d:72ff:fe88:5636/64 scope link valid_lft forever preferred_lft forever 3: wlan0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:1f:3c:1b:9e:5e brd ff:ff:ff:ff:ff:ff inet 84.246.161.89/28 brd 84.246.161.95 scope global wlan0 inet6 2a00:1268:1ff:f001:21f:3cff:fe1b:9e5e/64 scope global dynamic valid_lft 86374sec preferred_lft 14374sec inet6 fe80::21f:3cff:fe1b:9e5e/64 scope link valid_lft forever preferred_lft forever 704: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1360 qdisc pfifo_fast state UNKNOWN qlen 100 link/none inet 10.36.116.23/22 brd 10.36.119.255 scope global tun0
Fixed by: commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f Author: Balakumaran Kannan <kumaran.4353> Date: Tue Apr 2 16:15:05 2013 +0530 net IPv6 : Fix broken IPv6 routing table after loopback down-up I tested with F18, 3.9.4-200.fc18.x86_64 kernel, issue is not present.