Switch not pulling IP address from DHCP

[SLIutah]

First off I'd like to say that I LOVE these switches. They have been an answer to my prayers!

The issue I'm running into is that after switching to DHCP, the switches do not pull an IP address from the DHCP server. I have to factory reset them in order to get back into the management GUI. Here is my config:

Untagged VLAN with Public IPs from the DHCP server.
Tagged VLAN 100 for management purposes getting internal IPs from the DHCP server.

Also, either I'm having a blonde moment every time I touch these switches (very likely) or there is no way to make the switch pull it's management IP address from a vlan. I'd prefer these get an IP on my management vlan rather than a public IP address on the public untagged network.

[sirhc]

What firmware version are you running?

[SLIutah]

Forgot to mention the firmware version. Silly me. It's 1.3.3

[SLIutah]

It might be notable that I was able to get them to pull an IP address when I had them plugged into my local internal network when configuring them, but once I deployed them they wouldn't pull anything. In my lab they had a constant connection to the DHCP server. In the field they have to fully boot and power on the radio that feeds them which then has to boot before it can successfully get an IP address from the DHCP server. I pulled them back down from production to test in the lab again and it was again able to pull the IP address from DHCP. So I tested and turned them on a few minutes before putting them on the network. They didn't pull an IP address when doing it that way. I gave them a full 24 hours and still nothing. After a few days, one of them did pull an IP address, but only one out of 4.

[sirhc]

It might be notable that I was able to get them to pull an IP address when I had them plugged into my local internal network when configuring them, but once I deployed them they wouldn't pull anything. In my lab they had a constant connection to the DHCP server. In the field they have to fully boot and power on the radio that feeds them which then has to boot before it can successfully get an IP address from the DHCP server. I pulled them back down from production to test in the lab again and it was again able to pull the IP address from DHCP. So I tested and turned them on a few minutes before putting them on the network. They didn't pull an IP address when doing it that way. I gave them a full 24 hours and still nothing. After a few days, one of them did pull an IP address, but only one out of 4.

I would say you have guessed the answer here, the switch boots up but there is no DHCP server available so it fails over to the static IP address.

I am not sure how we should address this as people wanted the switch to fall back to the static IP address when DHCP failed.

This is one of those issues where how do you make everyone happy?

[SLIutah]

That makes perfect sense, except it's not failing back to the static.

I guess a workaround would be I could set the static up as something within my subnet but out of the DHCP range as a failback, but hope it goes to DHCP.

One challenge with it auto-defaulting to static is that most of these will be powering the radio that connects it to the DHCP server. Is there a way to make it so that if it is defaulted to static due to a failed DHCP request it will then re-request DHCP after a certain amount of time?

On the other note, is it possible to force the unit to use a certain vlan for the management IP address?

[sirhc]

That makes perfect sense, except it's not failing back to the static.

I guess a workaround would be I could set the static up as something within my subnet but out of the DHCP range as a failback, but hope it goes to DHCP.

One challenge with it auto-defaulting to static is that most of these will be powering the radio that connects it to the DHCP server. Is there a way to make it so that if it is defaulted to static due to a failed DHCP request it will then re-request DHCP after a certain amount of time?

On the other note, is it possible to force the unit to use a certain vlan for the management IP address?

I would set a static address for now and I will talk to Eric but I do not expect a fix for this soon as we are a tight schedule now for Vegas.

Think about it, the switch boots up and is told to acquire a DHCP address but the DHCP is not there because the backhaul link to the DHCP server is not up yet and could be several minutes if it is an AF link. All DHCP clients have a time out and most are a minute or less.

[jjonsson]

Chris,

I do normally run DHCP on all my equipment. Except for the Netonix switches. On them DHCP is not working very well. I ended up in situations, where I couldn't connect to the switch and had to connect with serial cable. Not nice when you have to drive several hours to get to the switch.

DHCP is something that actually works very well with the shitty old TOUGHswitches. Do it like them and you have a working system. I had all mine TOUGHswitches (Before I throwed them in the carbagecan and replaced them with Netonix) running DHCP and never had a problem with that.
If switch was rebooted and link had to come up before the switch could get an IP-address, that was no problem. I think the UBNT way of running DHCP is to check for DHCP and else assign fallback IP, then wait a little time and check DHCP again...

[billbuchan]

Hope this helps. DS Snooping ON on each port appears to eat the DHCP reply. Look at the General and the firmware forums.

Switch OFF the DS snooping feature.


---* Bill