Network connectivity troubles in XP11, works in XP10 with same config.

Question

• X-Plane
• Ubuntu 16.04
• Version 11.11r2 (latest non-beta offered by installer)
• See Log.txt below for hardware

Under XP10 I was able to have networked machines displaying side views, but I just upgraded to XP11, and I'm having trouble getting that working under 11 using the same configuration.  Details follow.

Details:

1. Both machines claim to send data (I'm not convinced!), and neither machine claims to receive it (per the network tab in the XP config settings).
2. The machines do have connectivity on the related ports over IPV6.  For example, I can do "nc -6 -u ::ffff:192.168.11.3 49100" on one and "nc -6 -u -l 49100" on the other, and happily send data across.  Thus, there's no firewall or other network blocker in the way.
3. The machines happily synchronize under XP10 using the same ports and IP addresses.  I've verified that the ports and IPs in the .prf files are identical under XP10 and XP11.
4. XP11 does exchange some limited data.  When the remote machine comes online, the master starts offering the remote's hostname as a possible network display.  If I shut down XP11 on the remote side, that choice stops.  So they're exchanging some data, just not enough to send flight data.  Guessing that's on some other port or protocol, so is a separate thing.
5. There appear to be two modes in the GUI: either I use the above mentioned hostname from the pulldown, or I enter an IP address and port.  Neither way works.  I've verified than when I use the IP/port option, the .prf file contains exactly the same address and port that it does under XP10, which works fine.
6. If I use the hostname option in the GUI, the GUI displays the proper IP address for that machine.

I investigated this as far as I am able, and this is what I've discovered.  I've tried setting the port number 49100, to make it easily searchable.  I can run "strace -e trace=network" against XP10, and I see the master machine sending lots of data to the network views, like this:

sendto(63, "ZOOM\23\0\0`A\0\0\200?\0\0\240@`\254\223A\0\0\0\0\0\0\0\0\0\0\0"..., 85, 0, {sa_family=AF_INET6, sin6_port=htons(49100), inet_pton(AF_INET6, "::ffff:192.168.11.3", &sin6_addr), sin6_flowinfo=0, sin6_scope_id=0}, 28) = 85

Note the port there (49100) and the IP (192.168.11.3) which is my network display.  XP10 sends a constant stream of these events to the remote side, and everything works fine!  Under XP11 using the same config, there is no data sent to port 49100.  I've tried capturing this data over 60 seconds of the plane sitting on the runway.  It acts like XP11 has simply decided it doesn't want to send data to the network, but I have no idea why.

I'd really like to get this working, since it's the major blocker for me at the moment from moving over to 11.

Thanks for any help, and all your work on XP.

I'm not seeing an attach button here, so Log.txt is pasted below.  Err, scratch that - it exceed the maximum message length :(.  Can't paste it.

Comments

I would like to add that per a suggestion on another forum, I tried disabling IPV6 entirely in my OS, hoping that XP would work on IPV4.  However, this made no difference to the above.

If this is a bug (which seems likely to me), then I will file a bug report about it, but since I'm uncertain what reason XP11 has for this, it's hard to know.

Answer 1

I did not see an issue with displays when I networked 2 Macs together as master & external visual. The master machine did not say it received data from the external visuals machine, but they both synced when actually flying around. I tried both the locked & independent view options.

It could be an issue with how your Linux system is set up, or it could be an OS specific bug. Make sure you set the external machine role to "external visuals." Try starting a flight before setting up networking--some times there are problems when there's no flight data to send between machines.

You can file a bug report if you think it could be Linux specific. Be sure to include step by step info on how you set up networking and a copy of the full log.

Comments

OK, thanks.  I just got it working!  Yay ;).  The key seemed to be what you said about doing it from within the flight.  I was setting it up from the main menu before entering a flight, and even after entering the flight it wouldn't sync.

It appears to be a little finicky about the order of doing things, but everything is working now.  Thanks a lot for your help.

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[deleted - investigating more]