On Mo, 09 Sep 2019, Axel Beckert wrote: > it's well-known that as of now no released Xymon version supports IPv6. > > What's nevertheless an issue of its own, is that, if even only a single > URL in hosts.cfg only resolves to IPv6 addresses(*), the xymonnet > process crashes as soon as it receives the DNS response. > > And since it seems to get this response > inbetween parsing hosts.cfg and conducting any tests, a single URL in > hosts.cfg may cause _all_ network tests to stop and go purple. > > (*) In this case it additionally was a ULA, i.e. inside fd::/8 (see > https://en.wikipedia.org/wiki/Unique_local_address) which > potentially might be relevant.
On Mo, 09 Sep 2019, Axel Beckert wrote: > Control: found 939846 4.3.30-1 I just tried to reproduce the issue with a freshly installed Debian forky and xymon 4.3.30-6. This still doesn't support IPv6, but didn't fail on the following hosts.cfg line: 194.8.194.78 ipv6-test # http://ipv6.ipv6-test.netcologne.de (ipv6.ipv6-test.netcologne.de has only an AAAA record, but no A record). I don't observe any crash of xymonnet or the like. Instead of this xymon http test shows red http://ipv6.ipv6-test.netcologne.de/ - DNS error as expected. Sadly I don't know, what change (between 4.3.30-1 and 4.3.30-6) could solved this issue, but at least 93_pcre2.patch, 95_fix_tls13_banner.patch and 103_openssl4.patch modify code in xymonnet/*.c files. Or if I have a look at your stack trace, the issue may have been in libc-ares2 (which was 1.18.1-3 on Debian 12 where I found xymon 4.3.30-1) vs. 1.34.8-1 in trixie. I tried to run a Debian 12 VM with xymon 4.3.30-1 but this also didn't run into this issue on my above test case. @Axel: Please check, whether you can still reproduce the issue on your system (maybe it's related on the ULA address, which I don't use in my environment?) with current xymon and/or current libc-ares2. Greetings Roland
