Re: [webmin-l] Strange issues with ICMP monitoring

[Joaquim H. <jo...@we...>]

Hi there

As stated in the post(s), Webmin 1.962 on Ubuntu 20.04.LTS.

We do indeed use fail2ban on the servers being "pinged", but the ping 
interval is set rather high.

The checking server all of a sudden starts reporting monitors as being 
down, but they are actually not. If I ssh into that checking server, and 
issue ping to the servers reported as being down by Webmin, I get a 
response. Every time.

If I reboot the checking server, which takes about 10-15 seconds, 
everything goes back to normal.

It sounds/looks to me like a "build-up" issue, but I've only ever seen 
this on that particular server. It happened with Ubuntu 18.04.LTS, and 
it's happening with Ubuntu 20.04.1.LTS.

It happens frequently, but not every day.

The checking server is not logging in to the remote servers, it's simply 
sending ICMP/pings.


-joho


On 2020-12-08 23:04, Eric Tykwinski wrote:
> Sorry new to the list, but what are you running?
> VirtualMin, Webmin, Cloudmin?
>
> My first guess would be a fail2ban issue as that is a popular 
> dictionary attack mitigation method, so a cluster of webmin servers 
> with an incorrect password on one would cause this.