Static vs Dynamic IP Address for Network Tests
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?
Thanks
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
Also, the last time I installed Xymon from scratch (version 4.3.0.0-beta2) it used the loopback address for the Xymon server (127.0.0.1) in the bb-hosts files. I had to edit the bb-hosts file to point my Xymon server to its IP on the network. If you didn't change the bb-hosts entry, then your Xymon server will still see itself at 127.0.0.1, no matter what IP the DHCP server assigned.
......Bruce
Bruce White Senior Enterprise Systems Engineer | Phone: 630-671-5169 | Fax: 630-893-1648 | bewhite at fellowes.com | http://www.fellowes.com/ Disclaimer: The information contained in this message may be privileged and confidential and protected from disclosure. If the reader of this message is not the intended recipient or an employee or agent responsible for delivering this message to the intended recipient, you are hereby notified that any dissemination, distribution or copying of this communication is strictly prohibited. If you have received this communication in error, please notify us immediately by replying to the message and deleting it from your computer. Thank you. Fellowes, Inc. -----Original Message----- From: Henrik "Størner [mailto:henrik at hswn.dk] Sent: Thursday, December 09, 2010 3:33 PM To: xymon at xymon.com Subject: Re: [xymon] Static vs Dynamic IP Address for Network Tests
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
To unsubscribe from the xymon list, send an e-mail to xymon-unsubscribe at xymon.com
participants (3)
-
bewhite@fellowes.com
-
henrik@hswn.dk
-
xymon.user.ml@gmail.com