Multitech Conduit mlinux DHCP issues


#1

Hi all,

For those of you using Multitech Conduit mlinux as your gateway I’d be interested to hear if you’re having problems with DHCP.

Reproducible scenario:

  1. Router with DHCP server is disconnected or powered off
  2. Conduit powers up or reboots, fails to get a DHCP lease
  3. Router with DHCP server is reconnected or powered up (conduit’s eth0 link state changes)
  4. Conduit never asks for a DHCP lease again. Device is useless until reboot.

It seems link state changes on mlinux don’t cause a DHCP Discover or Request. The only way to make a reliable gateway configuration is to use static IP addresses (which have their own limitations). The outdoor IP67 conduit has an external PoE injector (48v) so cannot be remotely reset without additional equipment or a site visit. Bah.

Can anyone suggest a fix for this?

Thanks
Ben


(Jac Kersing) #2

The only reliable solution is to use static IP.


#3

Thanks. That’s not the question I was asking though.


(Jac Kersing) #4

Or is it not the answer you wanted to get? You could add a script to the conduit that checks for a valid IP address every minute and restart the dhcp client if there is no valid IP address for 5 minutes. Another solution would be to replace the dhcp client with one that does not suffer these issues. The problem with both options is they might not work reliably.

Have you tried asking the question at the forum at MultiTech.net?


(Timmyhadwen) #5

For remote instances, perhaps a raspberry pi and a usb cable to the serial port would be a half useful workaround, at least while Conduit sort out there software! Im finding having the base on my desk is way more useful than I thought and would hate to have to go onto the roof (or further) every time something goes wrong!
PS: Yes DHCP is kinda broken :confused:


#6

@kersing It’s not that I didn’t appreciate the help, but I was trying to continue using DHCP for consistency. I knew I could use static addressing, but thought someone may have a fix. Your suggestion about using a DHCP watchdog script is fair, perhaps a cron job is in my future.

I will ask the question at the Multitech forum too, but this one’s much nicer.

Thanks
Ben


#7

@timmyhadwen I haven’t experienced any problems that weren’t fixable with ssh yet except the DHCP problem. Have you had any issues that need USB serial access?

I ask mainly because I have one on a roof and it’d involve security torx screws and field engineers and a personal visit to resolve.


#8

I’m running a Multitech with DHCP for about half a year now without any problems. But I have the luxury that it’s relatively easy for me to get physical access to the box if it was needed. Also the power to the multitech has been stable. I have rebooted it remotely quite a few times and it always came back up.

I did configure the network setup to send the hostname to the DHCP server, so I can access it by name instead of only ip address.