DHCP not working on Force200

The tech was installing a SM yesterday, after panning the dish, he called in to check all was OK, and I logged in remotely.

At this stage all was OK, he had logged into the unit  and was able to browse the internet, run speedtests etc.

He changed the ID of the radio to the customer number/ name, rebooted and then couldn't access the unit!

I could still see it and access the GUI however, but I noticed that although the LAN was connected ther was no DHCP address handed out. He tred connecting different devices, routers, laptops, changed PSU, still nothing.

I tried several things one a time, turned off DHCP, turned it back on, changed DCHP range, changed LAN IP, rebooted, and even upfdated the firmware from 3.2.2 to 3.41,  Also got him to test LAN cable. all to no avail. In the end he used a Ubiquiti radio and we elevated it! (he didnt have a spare Cambium radio on board, as most of our network is still UBNT)

Back in the workshop it is still showing th esame symptoms, i.e. no DHCP handed out

I can connect to it via the 'rescue' IP 169.254.1.1, also if I manually set the IP range on the PC to our normal customer LAN range, I can connect as normal.

I havent yet tried a factor reset, before I do I said I'd ask on here if anyone has seen similar? I knowI can RMA it , but want to check it's not some sort of procedural ''bug' I should know about for future reference

Please make sure DHCP server is at AP side. We block DHCP server behind SM by default, but it can be changed in SM network configuration: "DHCP Server Below SM" Enable/Disable.

Rgds,

ePMPMaster

I don't understand what you mean. As I understand it the LAN settings in the SM unit have an option for a local DHCP server, which works regardless of whether the radio is connected to an AP or not.

We have close to 100 units configured this way and this is the first one I have seen this issue with

can you clarify?

Thanks

I think ePMPMaster misunderstood your situation. He was referring to the ability to place an external DHCP server below the SM.

It is quite odd that this particular SM isn’t handing out dhcp addresses from its local server. Can you post a screenshot of your Configuration->Network page of the SM?

I’ve seen this happen but could never replicate the poblem. Changing the size of the dhcp up or down seems to resolve it. Over 2,000 or so cpes, ive noticed this happen 3 times at most. Nothing in the logs to indicate a problem, just no leases. Change the pool size up or down and is happy.

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Will do but it will be Tuesday before I get a chance to do so

I tried changing the pool range and size (up from 100- 120 to 102 - 120) no joy. Didnt try shifting the top end though.

Can you take wireshark capture and filter on bootp to see if the SM is responding to DHCP requests?

Here is a screenshot of the network config (I have other devices set like this working fine)

Here's some Wireshark captures, one from the device that isnt doing th eDHCP and one from another device configured the same that will give it out

I tried moving the whole DHCP range about and it makes no difference.

Before I factory default it I just want to know if there is anything else useful I can download for diagnostic purposes that may be of use to Cambium to figure out what happened?

Hi,

Did this problem get resolved?  As I believe I have the same issue with a Force180.  It is urnning ver4.4.

Never noticed this before with any other Force180s or ePMP1000s.

After rebooting the subscriber, the DHCP is back for a wee while, then does the IPs are not provided.

The DHCP is above the AP, as standard.

thanks,


@Jason Hills wrote:

Hi,

Did this problem get resolved?  As I believe I have the same issue with a Force180.  It is urnning ver4.4.

Never noticed this before with any other Force180s or ePMP1000s.

After rebooting the subscriber, the DHCP is back for a wee while, then does the IPs are not provided.

The DHCP is above the AP, as standard.

thanks,


You should update to 4.4.1... there were a number of DNS/DHCP fixes IIRC.

The fixes were for F300, not F200.

It is better to open support case for that, because it is not something known.

Dmitry

I'd the same problem on a customer SM using F200, it was using fw version 3.2.2 in nat with pppoe and dhcp server on lan side. If I try to upgrade to 3.5.6 or 4.4.3 dhcp immediately stops working over lan. If I revert back to 3.2.2 everything is fine.

Tried everything... then I tried to reset F200 to factory default, then I upgraded to 3.5.6, then I restored our default config and it immediately worked! So I think the problem is something concerning old config with old firmwares. The weird think is that I've already upgrades tons of SM (both F200 and F180) and never had a problem like that!