On 2026-09-08 19:10:36 +0200, Vincent Lefevre wrote:
> On 2026-09-08 17:04:11 +0000, Andy Smith wrote:
> > Out of interest, do you have any way to see what soruce address it is
> > choosing when you do wget?
>
> The error occurs at the socket creation, thus before a source address
> is used:
>
> socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = -1 EAFNOSUPPORT (Address family
> not supported by protocol)
And on another machine without IPv6 connectivity (because it is
also at ENS Lyon) but with IPv6 enabled in the kernel:
disset:~> ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host noprefixroute
valid_lft forever preferred_lft forever
2: enp1s0: <BROADCAST,MULTICAST> mtu 1500 qdisc mq state DOWN group default
qlen 1000
link/ether 00:4e:01:fc:2d:01 brd ff:ff:ff:ff:ff:ff
altname enx004e01fc2d01
3: enp0s31f6: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state
UP group default qlen 1000
link/ether 00:4e:01:fc:2d:00 brd ff:ff:ff:ff:ff:ff
altname enx004e01fc2d00
inet 140.77.12.53/23 brd 140.77.13.255 scope global dynamic enp0s31f6
valid_lft 50087sec preferred_lft 50087sec
inet6 fe80::24e:1ff:fefc:2d00/64 scope link proto kernel_ll
valid_lft forever preferred_lft forever
4: enxc84bd6cd3baf: <BROADCAST,MULTICAST> mtu 1500 qdisc fq_codel state DOWN
group default qlen 1000
link/ether c8:4b:d6:cd:3b:af brd ff:ff:ff:ff:ff:ff
There is a real IPv6 connection attempt:
disset:~> strace -o str.out wget http://42.be
--2026-09-08 19:32:28-- http://42.be/
Resolving 42.be (42.be)... 2001:470:1f15:29a::1
Connecting to 42.be (42.be)|2001:470:1f15:29a::1|:80... failed: Network is
unreachable.
with strace output showing:
socket(AF_INET6, SOCK_STREAM, IPPROTO_IP) = 3
connect(3, {sa_family=AF_INET6, sin6_port=htons(80), sin6_flowinfo=htonl(0),
inet_pton(AF_INET6, "2001:470:1f15:29a::1", &sin6_addr), sin6_scope_id=0}, 28)
= -1 ENETUNREACH (Network is unreachable)
But I don't know what source address is used (fe80::24e:1ff:fefc:2d00/64
has scope link only).
--
Vincent Lefèvre <[email protected]> - Web: <https://www.vinc17.net/>
100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/>
Work: CR INRIA - computer arithmetic / Pascaline project (LIP, ENS-Lyon)
