Gargoyle Forum

Weird issue I noticed recently. I connected a Brother printer to my network and it was allocated an IP address via DHCP (in this case it was 172.16.0.21 and the Brother hostname was listed under connected hosts), I later changed the IP address via assign static IP address under DHCP. I rebooted things, and the printer took on the new IP address. A few days later I connected something else via DHCP, and it was allocated 172.16.0.21. Under connected hosts there were 2 Brother hostnames listed, one was the real one, and one was a ghost one listed for the device that had the 172.16.0.21 IP address.
I assume there is some sort of hostname cache on the router that may need clearing in such cases, is that correct?

It comes from several places
/tmp/dhcp.leases
/tmp/dhcpv4configleases.gargoyle

Is the ghost entry in one of those?

It may have cleared out by now
It wasn't in
/tmp/dhcp.leases

and I couldn't find
/tmp/dhcpv4configleases.gargoyle

I'll have to try and get 172.16.0.21 allocated again to to see if it come up with the hostname Brother.

Ok I set a VM IP to 172.16.0.21 and sure enough, in the connected hosts screen, hosts with active connections section it shows the host name as Brother.

So was it in either of those files when you got it to appear again?
And, what version are you running.

Lantis wrote: ↑

Thu Aug 31, 2023 9:11 am

So was it in either of those files when you got it to appear again?

No, which made sense since I had set the IP as a static IP on the VM, so I wouldn't expect them to appear in DHCP files.
I had a look in other files also, looking for 172.16.0.21 or Brother, but none of the files I tried looking in had the ip or hostname in them.

Lantis wrote: ↑

Thu Aug 31, 2023 9:11 am

And, what version are you running.

1.12.0

I can’t really recall how it works on 1.12, but I suspect a stale ARP cache
cat /proc/net/arp

I tried "cat /proc/net/arp", it listed the 172.16.0.21 ip address but the mac address was different to the one for the brother printer. So I am guessing that's not the cause.
I found a hosts.sh file in the WWW folder, thinking that's the script that generates the connected host page, and had look to see if it would give me a clue about what file might contain the ip and hostname. I could see the section that dispays the active connection, but couldn't work out where it got its info from.

/var/lib/gargoyle/define_host_vars.sh
There's also a section that comes out of the gargoyle_header_footer app.

I have had a play with nslookup both on Gargoyle and on a pc, and it seems that Gargoyle is definitely storing the two IP's with brother as the hostname. But no idea where.
I am wondering is there a way to do the equivalent of
ipconfig /flushdns on Gargoyle?

Found it.
It was in /etc/hosts, don't know how it got in there.
Anyway I made a copy of original, then deleted the line listing 172.16.0.21 Brother
Now Nslookup only shows the one IP address for Brother.