DHCP IP lease renewal

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Douglas
Posts: 55
Joined: 15 Feb 2018 12:04

DHCP IP lease renewal

Post by Douglas » 07 Mar 2018 10:16

Hi
I’ve been randomly losing connection to my VMs. I thought it was an issue with the VMs themselves but now find most suffering from a DHCP Client event ID 1003:
“Your computer was not able to renew its address from the network (from the DHCP Server) for the Network Card with network address 0x005056B34488. The following error occurred: 0x79. Your computer will continue to try and obtain an address on its own from the network address (DHCP) server.”
This is occurring halfway between the lease granting and expiry times. The Event Logs show the issue started when I installed CG. If a VM is rebooted it invariably gets the same address, so there is no problem with the range being too small at 10, with 4 of them Fixed.
How do we ensure IP lease renewal always works?

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david
Posts: 157
Joined: 08 Aug 2015 20:38

Re: DHCP IP lease renewal

Post by david » 07 Mar 2018 12:09

Hi,

If the DHCP server on your CG is activated (mode dhcp on), please make ensure that you don't have another active DHCP server on your internal LAN. Can you please double check this? Also, please verify that nothing on your client machines blocks the DHCP renewals

My understanding is that you encounter this issue for the renewals only. Con you please confirm that? If so, you should not have the same symptoms with fixed DHCP IPs.

Best Regards,
David Jan
CacheGuard Technical Team
https://www.cacheguard.com

Douglas
Posts: 55
Joined: 15 Feb 2018 12:04

Re: DHCP IP lease renewal

Post by Douglas » 07 Mar 2018 15:32

Thanks David
I believe there is no other DHCP server on the internal lan, and
ipconfig /all | find /i “DHCP Server”
returned only the CG internal IP.

Same symptoms with the fixed IPs. Perhaps WS2016 Essentials is doing something that's not needed with CG.
I've created a fresh CG with a higher US number, which I guess must be >= fixed plus range.
I did notice earlier several leases with no hostname.
I'll report back whether the issues contunues with the new CG.

Douglas
Posts: 55
Joined: 15 Feb 2018 12:04

Re: DHCP IP lease renewal

Post by Douglas » 07 Mar 2018 15:53

I note WS2016 Essentials defaults to DHCP Server off, and I confirm no related services or roles are active, so it doesn't seem to be the cause.

Douglas
Posts: 55
Joined: 15 Feb 2018 12:04

Re: DHCP IP lease renewal

Post by Douglas » 07 Mar 2018 16:58

If there's no quick solution to this, is there any reason why I should not turn off CG's DHCP and enable WS2016's instead?

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david
Posts: 157
Joined: 08 Aug 2015 20:38

Re: DHCP IP lease renewal

Post by david » 07 Mar 2018 17:29

Hi Douglas,

I spent the afternoon trying to reproduce your case in our lab and I can confirm that CG's DHDP version EH-1.3.5 has some difficulties to renew a DHCP lease in certain circumstances (). We will fix this issue in the next release (EH-1.3.6).

In the meantime you can activate your WS2016 DHCP instead without any difficulties. Think about disabling CG's DHCP first.

Best Regards,
David Jan
CacheGuard Technical Team
https://www.cacheguard.com

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charles
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Joined: 06 Nov 2014 16:23
Location: Paris
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Re: DHCP IP lease renewal

Post by charles » 09 Mar 2018 15:10

Hi,

We are pleased to announce that we just released CacheGuard-OS version EH-1.3.6. This new release fixes the bug that prevented to a renew a DHCP lease in certain circumstances. Now you can safely reactivate CG's DHCP server.

Please note that we can't test the DHCP server with all existing clients and the issue can persist in some unknown cases. If your clients are still unable to renew their DHCP leases, please feel free to contact us so we can investigate more.

Best Regards,
Charles Tajvidi
IT Technical Architect
http://www.cacheguard.com

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