[Freeswitch-dev] Issue around IPv6

[Tamas]

Hello,

My original issue was that after some time (unable to find a rule when)
registering gateway stopped suddenly working and went to status DOWN and
state was FAIL_WAIT.
In the logs I saw that it was trying to register continuously, but there
were no REGISTER packet sent out anymore. Clients registering to this
box were able to register, just it was not able to register to the
upstream box (FreeSWITCH too). Registering scheme:
clients--->FS local---(NAT)--->FS public

When I've caught such a case again, I was stracing FS processes and
found this:
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2393, ...}) = 0
futex(0x2ac3092ead94, 0x85 /* FUTEX_??? */, 1) = 1
futex(0x2ac3092ead40, 0x81 /* FUTEX_??? */, 1) = 1
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 34
setsockopt(34, SOL_SOCKET, SO_BROADCAST, [1], 4) = 0
connect(34, {sa_family=AF_INET, sin_port=htons(4242),
sin_addr=inet_addr("82.45.148.209")}, 16) = 0
getsockname(34, {sa_family=AF_INET, sin_port=htons(32824),
sin_addr=inet_addr("192.168.1.38")}, [1451698946064]) = 0
close(34)                               = 0
socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP) = 34
connect(34, {sa_family=AF_INET6, sin6_port=htons(4242),
inet_pton(AF_INET6, "2001:503:ba3e::2:30", &sin6_addr), sin6_flowinfo=0,
sin6_scope_id=0}, 28) = -1 ENETUNREACH (Network is unreachable)
close(34)                               = 0
stat("/etc/localtime", {st_mode=S_IFREG|0644, st_size=2393, ...}) = 0
futex(0x2ac3092ead94, 0x85 /* FUTEX_??? */, 1) = 1
futex(0x2ac3092ead40, 0x81 /* FUTEX_??? */, 1) = 1

>From this I guess, my issue relates to IPv6. That is right that the box
has IPv6 address on the eth interface (ubuntu default), but this has
worked for some days or some hours (varies) without this issue. So
something might happen for which FS suddenly started using the IPv6
interface address (which is not configured well).

I've found tha given public IP (82.45.148.209) in switch_find_local_ip
function and have found that this is a root DNS server and the role of
this function is to find the local IP address. As I was looking for the
source, probably something sent wrong family to this function (AF_INET6
in place of AF_INET). Maybe this is a trivial issue for the experts...

I'm sure that if I remove the ipv6 things from my system it will be OK,
however I had similar issue on a box with no ipv6 address to. I'm not
sure if it is the same/similar issue or not, but the symptoms looks
similar. Unfortunately we had to restart that box (production) and since
that the problem disappeared (that was maybe fixed - the case happened
about 2 weeks ago).

I think some users - mainly on test systems like I have - might face to
this issue so it might be worth to take a look, why had FS suddenly
tried to send packets on ivp6. This could be a system issue too -
something crazy with Xen or Ubuntu?

Thanks in advance!

Regards,
    Tamas

ps: FreeSwitch Version 1.0.trunk (10567M)
Ubuntu Hoary (8.04) under Xen