DCE device hostname resolution

DCIM_Support · ‎2020-07-03

Hi,

My End User is having issues with resolving a monitored device IP to the given hostname in DCE monitoring. This seems to be happening for a specific UPS unit which has like the rest of the monitored devices been registered on the DNS server. The UPS is running NMC firmware version 6.4.6 and the End User is able to get the name resolved on the network.

It is only on the DCE desktop client that the IP is not resolving to the hostname as we have tested using the network troubleshooting tools on the DCE web interface and we are able to resolve the IP to Hostname.

The UPS was discovered and left for 2 days with the hostname still showing the IP address instead. Is there something we are perhaps overlooking? Is this an isolated issue?

DCE is currently running v7.4.0.

Any suggestions on how we can troubleshoot and resolve this issue?

Kevin

DCIM_Support · ‎2020-07-03

Hi Kevin,

Any testing I've done in the lab here was pretty quick to update the IP to hostname on the DCE server. It's been that easy here for quite some time. You mention is it only one UPS doing this. I'm assuming the customer have other devices that are working OK,

How are these different (working vs not working)?

Are they on different network segments?

Are hey all in the same DNS server?

Do both working and not working have both forward and reverse lookup?

Have you rebooted the DCE server?

Does a local laptop use the same DNS server? Can it ping or do a lookup on the UPS by hostname? Other devices?

It should just work but have you tried removing and re-adding the device?

Steve

DCIM_Support · ‎2020-07-03

Hi Steve

Thanks to Kevin for assisting here, I am the end user.

Answers to your questions:

How are these different (working vs not working)? - No, we have not had any of the UPS's or PDU's on the DNS, and hence they've all shown just the IP address in the hostname field, this is causing a problem on the reports, as we have almost 1500 devices, and a list of IP's does not help. We are now trying to add them to DNS in order to resolve a sensible name on the application and report. We have added a few devices to the DNS in order to get it working, once we have the process sorted, we will add the remainder. None of the units added to our DNS are resolving.

Are they on different network segments? Yes, they all on different segments / subnets, but all routed appropriately, so pingable and accessible from the main DCE subnet. Using the resolve tools on the UPS, it can resolve the name and IP from the DNS.

Are hey all in the same DNS server? Yes, all on one DNS server, and also the same DNS server for the DCE.

Do both working and not working have both forward and reverse lookup? None working, and forward and reverse look up confirmed working. Checked with a seperate machine in the same subnet as DCE, another machine in the same subnet as the one main test UPS in my lab, using DCE web to verify the reverse and forward lookup, as well as the onboard DNS check tools on the UPS web interface, all resolve the name from IP, and IP from name.

Have you rebooted the DCE server? Yes, numerous times, just tried another reboot 10 minutes ago.

Does a local laptop use the same DNS server? Can it ping or do a lookup on the UPS by hostname? Other devices? Yes, it uses the same DNS, and can ping and do lookup on UPS by Hostname. DCE and the test UPS's

It should just work but have you tried removing and re-adding the device? Yes, also removed it from the "saved discoveries" rebooted the server, and tried a new discovery....numerous times....

I really hope you can assist with any other tests to resolve this.

Please let me know if any further info is required.

Regards

Steven

DCIM_Support · ‎2020-07-03

Hi Steven,

Sorry I didn't get back to you sooner.

IN my experience, if DCE has the correct DNS entries and DNS has forward and reverse lookups, it should just work.

Is this a hardware server?

If hardware or VM with public and private networks, are the public and private IP schemes different? (something like 10.10.x.x on one side and 192.168.x.x on the other)

If you go here:

http:///nbc/status/Troubleshoot

Can you ping and resolve by hostname / fqdn?

Steve

DCIM_Support · ‎2020-07-03

Hi Steve

I logged onto the server late yesterday....and the devices I added to DNS on friday, that did not resolve on Friday were resolved yesterday in DCE, so it is working.

The additional question now, is what is a reasonable wait time before resolving, is there a way to speed it up? A few minutes would be OK, but 24 or 48 hours seems too long, any settings I can look at to improve this?

Thanks

Steven

DCIM_Support · ‎2020-07-03

Hi Steven,

There are no settings that you can change specific to this functionality. From what I have experienced in my lab with 50-80 devices, it usually takes less than an hour to resolve. I have seen some quicker.

If your system i staking 24-48 hours, maybe you should check resources. Either increase RAM / disk space (if it's a VM, be sure to add a new disk and not increase the default 18g drive) or slow polling down to see if you can speed other actions up. If you've also got NetBotz and use surveillance, changing frame rate and resolution to lower settings will allow the system to perform other actions that it may be unable to perform otherwise.

Maybe even test with a trial VM. Add a single device that has a hostname. If it's taking forever in that configuration, perhaps there are VM host or network related issues.

Thanks,

Steve.

DCIM_Support · ‎2020-07-03

Thanks Steve

I will add a few more devices to DNS and check how long it takes to resolve. Do I need to remove and re-add them, or will hostname automatically resolve if it finds it in DNS?

To answer the above questions:

The server is VM based, we have allocated additional storage of which we are using 24%. (Separate 100G drive). We also only have a private IP scheme, one internal IP.

Maybe it is RAM limited, I dont know. How do I find the quantity of RAM installed / used? is there, this may assist.

We have one x Netbotz installed as test only.

Thanks

Steven

DCIM_Support · ‎2020-07-03

Hi Steven,

I would be guessing if I said it will work more quickly one way or the other but in both cases, device already added or device added after DNS entries (forward and reverse) configured, the hostname will eventually get associated with the device in DCE.

Steve

DCIM_Support · ‎2020-07-03

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