08-07-2012 02:47 AM
Hi,
we use LMS 4.2.1 and we noticed a strange behaviour when starting a discovery. From aprox. 160 devices some devices are displayed as IP Address instead of hostname. Every device is DNS resolvable and has a value for "hostname"
I´ve tried every possible option in the global discovery settings but some devices have the IP instead of their hostname
Can you tell me how to fix this? Thank you.
Chris
Solved! Go to Solution.
08-07-2012 03:46 AM
DNS is often not understood and just as often implemented badly
When it is working correct you can do 2 things:
ping hostname
will start ping towards the IP address of the host.
ping -a
will resolve the ip to a hostname if possibe and then start a ping towards the IP address.
Often only the first works. Reverse lookup is required by LMS as well.
if you can fix the DNS you can always create a local hosts file
Cheers,
Michel
08-07-2012 03:46 AM
DNS is often not understood and just as often implemented badly
When it is working correct you can do 2 things:
ping hostname
will start ping towards the IP address of the host.
ping -a
will resolve the ip to a hostname if possibe and then start a ping towards the IP address.
Often only the first works. Reverse lookup is required by LMS as well.
if you can fix the DNS you can always create a local hosts file
Cheers,
Michel
08-07-2012 04:10 AM
Hi Michael,
thank you for your reply. It works. The second one takes a bit longer till the first ping gets through but it works.
Have a nice day,
Chris
08-07-2012 06:48 AM
I beg your pardon, Michel. I´ll check the DNS entries once again and give it another try. Thank you
08-07-2012 06:53 AM
Tag Christian,
So does the second 'ping -a' resolve to a hostname?
Perhaps post a screenshot of the global settings of the discovery
Cheers,
Michel
08-07-2012 07:21 AM
Tag Michel,
yes, i´ve checked the DNS entries with our server team and they told me that te reverse-lookup are not entered for that devices although i can ping a device with ping -a
Strange.
Well, i´ll enter the missing reverse-lookups and will see if these solves the problem. Thank you for your time.
Chris
08-08-2012 01:46 AM
Michel,
the reverse entries are now configured in the DNS Server and the discovery works now. Great, thank you.
Cheers,
Chris
08-08-2012 01:57 AM
Christian
You may find that in (DFM) fault management devices remain with their IP address only.
Easiest solution is to disable the fault management module, wait for an hour or so. And then re-enable it again.
This will make DFM remove the devices from its repository and rediscover them afterwards.
This will use at bit of CPU :-)
Cheers,
Michel
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