Hi: Doing some tests with 2.6.0-test2-mm2 and IPv6 over IPv4 tunnels I come across the error message in the subject: dardhal:~# ip tunnel add sixbone mode sit remote 64.71.xxx.xxx local 213.0.xxx.xxx ttl 255 ioctl: No buffer space available Tracing the previous command shows the following (relevant part only): socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 3 ioctl(3, 0x89f1, 0xbffff7d8) = -1 ENOBUFS (No buffer space available) dup(2) = 4 fcntl64(4, F_GETFL) = 0x2 (flags O_RDWR) brk(0) = 0x805e000 brk(0x805f000) = 0x805f000 brk(0) = 0x805f000 fstat64(4, {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 4), ...}) = 0 old_mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x40012000 _llseek(4, 0, 0xbffff5f0, SEEK_CUR) = -1 ESPIPE (Illegal seek) write(4, "ioctl: No buffer space available"..., 33ioctl: No buffer space available ) = 33 close(4) = 0 munmap(0x40012000, 4096) = 0 close(3) = 0 exit_group(-1) = ? This same command has worked for me previously, even after several IP changes (local tunnel enpoint on a dynamic IP). Maybe I am doing something wrong, but my box configuration seems to be the same as it was some hours ago. Some (hopefully) useful data follows: # ip -6 link show 3: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 6: sixbone@NONE: <POINTOPOINT,NOARP,UP> mtu 1504 qdisc noqueue link/sit 213.0.xxx.xxx peer 64.71.xxx.xxx 7: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP> mtu 1524 qdisc sfq qlen 3 link/ppp # ip -4 address show 7: ppp0: <POINTOPOINT,MULTICAST,NOARP,UP> mtu 1524 qdisc sfq qlen 3 inet 213.0.xxx.xxx peer 213.0.xxx.xxx/32 scope global ppp0 # ip -6 address show 6: sixbone@NONE: <POINTOPOINT,NOARP,UP> mtu 1504 qdisc noqueue inet6 2001:470:1f00:xxxx::xxxx/127 scope global inet6 fe80::d500:c95d/128 scope link # ip -6 tunnel show sit0: ipv6/ip remote any local any ttl 64 nopmtudisc sixbone: ipv6/ip remote 64.71.xxx.xxx local 213.0.xxx.xxx ttl 255 I don't know what other information could be of interest, but just ask. Regards, -- Jose Luis Domingo Lopez Linux Registered User #189436 Debian Linux Sid (Linux 2.6.0-test2-mm2) - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html