[arm-allstar] DNS Query

[Doug Theriault]

I use dns-query command to monitor the IP address of several nodes that 
I manage via reverse SSH tunnels.  Custom script emails me if there's 
been a change in the IP address for the nodes router and a reverse ssh 
tunnel has dropped or is restored.

All my nodes/hubs are deployed using hamvoip distro, rPI3B+ based and 
use two registration lines in iax.conf; one to allstarlink.org, the 
other to hamvoip.org.  Allstarlink is listed first, followed by a line 
to register with hamvoip.

The script detects when an address has changed and automatically 
restores reverse ssh tunnel;  DHCP lease expiration is typically the 
cause, changing the IP address of the router for the node/hub.  To date 
its been working fine for quite some time.

As of Aug 11th, 16:55 I started seeing IP addresses on several nodes 
changing IP's. 4 to 5 / hr, peaked at about 20/hr couple days ago.  It 
seems to be slowing down but still occurs.  Flips between two IP 
addresses.  At first I suspected Vz, but given my config, I am wondering 
if its because there is a slight difference between the two registration 
services I am using.

I changed two of my nodes (ones which used Vz Cell routers) to use a 
simple "curl -s icanhazip.com" instead of dns-query and both those nodes 
IP addresses are stable using the curl method.  So I suspect I am 
getting different IP address when querying using dns-query.  Sometimes I 
get the NULL return which is fine, the script retries.  But the flip 
flopping IP change is baffling.

Questions:

1.  Am I creating a problem by registering nodes with both 
allstarlink.org and hamvoip ?

2.  Is there a write up somewhere on how dns-query works?  Does it 
utilize a file cache or does it query both allstarlink.org and hamvoip 
servers returning IP address of whichever server responds first?  Or is 
this command specific to hamvoip distro only?

3.  I have heard operators say they regularly reboot their nodes to 
prevent "problems".  I do not do this, I've had uptime on couple nodes 
of almost a year.  Is it recommended to regularly reboot a node to 
prevent any issues?


thanks in advance,

-- 
73,
Doug - NO1D