[Xymon] IPv6 debugging on xymon 4.4 (was Re: Roadmap/GitHub?/IPv6)

[Christian Herzog]

> Agreed. I'm a bit torn at the xymonnet v xymonnet2 split here, simply due to
> how some of the code diverges at this point. I suspect adding IPv6 branching
> into xymonnet will be easier (or at least easier to validate).
this decision is way above my paygrade :)
But we (the xymon community) need to do something since IPv6 is coming, and
fast.

> > > and xymond record
> > > management (using conn tests as sources) might be the most useful.
> > meaning what exactly?
> Correct. xymonproxy is another component that will need work, but
> client->xymond and anything at all (xymonnet/xymongen, etc) talking to an
> IPv6-only xymond would be very helpful. xymongen needs to download full
> xymondboard copies from xymond, so it's really about catching any
> assumptions out there on IP size or host lookups.
can you be more specific about what you would like to have tested?

what I can say already:
> > > For the short term, testing xymonclient messaging
> > meaning client reports to IPv6 XYMONSERVERS?
specifying IPv6 XYMONSERVERS on the client doesn't work. No reports coming in.

also, any hosts.cfg entry seems to get resolved to IPv4 only, even if the host
entry is IPv6. As soon as I cut IPv4 connectivity on a dual stack host, conn
turns red even if IPv6 is working fine. Probably xymonnet <-> xymonnet2 again.


> Would be good to disable BFQ too if it's enabled, since local components
> will short-circuit to using that for message submission instead of TCP in
> 4.x
this [1] BFQ? *confused*

[1] https://algo.ing.unimo.it/people/paolo/disk_sched/

I've also been thinking about how I would like xymon to behave on dual stack
hosts: in my experience, IPv4 networks are still quite a bit more stable than
IPv6 (I've seen sporadic PD issues, sudden IPv6 routing problems in the middle
of Europe etc), so ideally we would have v4/v6 tests on supported services on
dual stack hosts. I don't know if this means splitting each tests into two
halves or duplicate the whole host entry or something else entirely, but we
need to be able to deal with "v4 is working but v6 isn't" or vice versa....

thanks,
-Christian