remote syslog: host address must be numeric.

[David Arnstein]

I have two RT-AX86U with latest firmware. I find that the remote logging server address must be numeric, ie 100.200.300.400. It cannot be a fully qualified domain name (FQDN) such as loghost.mynetwork.com.

I can accept that, but where Asus falls down is that no feedback is provided to the user in the web interface. It silently accepts the FQDN, and no log messages are sent from the router to the syslog server.

 

[ColinTaylor]

A local hostname or a FQDN works fine for me.

Make sure your router is configured to resolve local hostnames (Tools > Other Settings > Wan: Use local caching DNS server as system resolver = Yes).

EDIT: Just realised that you're probably not using Merlin's firmware so the above option is not available to you. So the problem is actually that your upstream DNS server has no record of your local hostnames.

 

[David Arnstein]

EDIT: Just realised that you're probably not using Merlin's firmware so the above option is not available to you. So the problem is actually that your upstream DNS server has no record of your local hostnames.

Hello Colin,

Not sure about your theory. My upstream DNS server is actually my rsyslog server. I just verified that I can ssh in to the server from itself, using its FQDN. So as far as I can tell, I have configured DNS on my server OK.

I used the "Network tools" feature of my Asus router to ping my DNS/rsyslog server, using the server's FQDN. That worked fine.

 

[ColinTaylor]

Am I correct in assuming that you're not using Merlin's firmware? I've never had a problem using a FQDN in that field, but I've never tried it with stock firmware.

 

[David Arnstein]

Am I correct in assuming that you're not using Merlin's firmware? I've never had a problem using a FQDN in that field, but I've never tried it with stock firmware.

Correct. I am using the official AsusWRT firmware. If I were to switch to Merlin, the only benefit to me would be this little problem right here. How would you compare the reliability of Merlin vs official firmware?

 

[ColinTaylor]

Just as a sanity check what do you get if you SSH into the router and do an nslookup myservname ?

 

[David Arnstein]

Well Colin, this just got interesting. I did as you asked and I see that my router is actually using DNS server 1.1.1.1. So I was wrong. And nslookup could not resolve the FQDN:

Server:    1.1.1.1
Address 1: 1.1.1.1 one.one.one.one

nslookup: can't resolve '...

I still don't understand this. My server FQDN is registered properly, I access it from two different countries.

 

[ColinTaylor]

Ah, just realised that your syslog server is located on the public internet. I was assuming it was on your LAN. So yeah, strange DNS problem...