[arm-allstar] Two nodes on the same network won't connect to

ssedgwick ssedgwick at suddenlink.net
Sun Jul 22 12:35:16 EST 2018


Thanks Doug for the detailed explanation. I forgot to mention that I did change routers, so I assume that is what caused the problem.

The old cheap D-Link DIR-842 router worked fine when it came to allowing me to connect two nodes on the same network
but it was giving me other problems with disconnecting for the internet from time to time so I upgraded to a 
“MUCH BETTER” much more costly ASUS AC2900 / RT-AC86U router.  Everything went fine as far as I knew.  That was until
I tried connecting two node connected to the ASUS router.   Apparently the ASUS AC2900 / RT-AC86U router does not support hairpin loopback.

Everything is working fine now.  Thanks again for everyone’s help.

73,
Steve_WB8GRS


Steve,

 I think you have the answer from the howto but here is why it probably
doesn't work. When a node asks for the IP address information of another
node it gets the public IP address for that node. So if you have two
servers on you LAN and they try to connect they are using the public IP
address. Many routers can handle this. The slang for it is hairpin
loopback. The router knows when it sees its public IP that the data goes
back to the LAN. In this case it does use the port forwarding tables to
know where to send it using its port number.

If your router does not do hairpin loopback then you must put the local
(LAN) address in each server pointing to the other server. This would
include the port.  IP_address:port  This is done in the [nodes] stanza
towards the end of rpt.conf. While not mandatory it is a good idea to have
your servers on different iax ports. If two were on the same port you could
only port forward to one but you could still setup internal routing using
the LAN IP address.


*73 Doug*

*WA3DSP*

*http://www.crompton.com/hamradio <http://www.crompton.com/hamradio>*


On Sat, Jul 21, 2018 at 10:19 PM, "ssedgwick via arm-allstar" <
arm-allstar at hamvoip.org> wrote:

> This one has got me stumped.
>
> I have two node connected to the same router in my home.  One is connected
> to the routers using Ethernet and the other node is connected via WiFi.
> All port forwarding is setup for both nodes.  Both nodes can connect to
> other nodes outside my home network and nodes outside my network can
> connect to either of these nodes.  Of course both nodes show up as
> registered and both nodes download the rpt_extnodes list correctly.  Both
> nodes are running the lastest hamVOIP with latest updates.  All seems well
> up to this point.
>
> The problem is if I try to connect these two nodes together, they won’t
> connect.  I seem to recall seeing this issue before, but looking back in
> earlier email I could not find it, so I’m hoping someone knows the answer
> why they won’t connect to each other?
>
> Thanks,
> 73,
> Steve_WB8GRS


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