Re: [xymon] Static vs Dynamic IP Address for Network Tests

[Henrik "Størner" <henrik (at) hswn.dk>]

In <AANLkTin6TCMEe-VRBMqADPeRC9O7QT9GKWkRJ-MBcNsT (at) mail.gmail.com> John <xymon.user.ml (at) gmail.com> writes:

>I'm using Xymon 4.3.0-0.beta2. I have a server with a static address listed
>in bb-hosts as <static ip> <hostname>. The server was reconfigured to use
>DHCP and it acquired a new, different dynamic IP. I didn't make any changes
>to the bb-hosts file but xymon didn't seem to care the server's address had
>changed. It began testing the host with it's new IP address like nothing was
>different. Historical data is all there, no alarm was triggered. I
>understand the hostname correctly resolves to the new IP but I don't
>understand why xymon isn't trying to test the old static IP, and why it
>didn't give some indication the address had changed. It just so happens that
>I'm glad it went smooth but I expected to have to reconfigure the bb-hosts
>file; specifically, to change the <static ip> field for that host to
>0.0.0.0. Can anyone explain this behavior, and how to get xymon to alert if
>a host with a static IP address has it's IP changed?

Very simple explanation: Xymon does a DNS lookup on the hostname to determine
the IP, and if it succeeds then it will use the DNS-provided IP - regardless
of what is in the bb-hosts file.

You can force Xymon to use the bb-hosts provided IP with the "testip"
tag on the host entry.

There is not a built-in method of checking whether the IP-address has
changed, or if the DNS-IP differs from the bb-hosts IP.


Regards,
Henrik