What's new

AC68U won't pick up dhcp from ISP - MAC clone issue?

  • SNBForums Code of Conduct

    SNBForums is a community for everyone, no matter what their level of experience.

    Please be tolerant and patient of others, especially newcomers. We are all here to share and learn!

    The rules are simple: Be patient, be nice, be helpful or be gone!

canuck in the wilderness

Occasional Visitor
My AC68U occasionally - but not very often - picks up an address via dhcp from my ISP. For the last while, though, I cannot get an address no matter what I do.

I have:
  • erased nvram (mtd-erase2 nvram via ssh)
  • done various of the 30-30-30 (WPS or reset button) methods
  • reset from the mini-tool
  • reset from the admin GUI
  • rolled back the FW from current to 378_9313 stock
  • refreshed the modem or reprovisioned it (via the ISP as it is about 20 km away from me - I'm connected via Ubiquiti radios to it) numerous times
  • changed cables from my managed switch to the AC68U
I've looked numerous times in the nvram and there is no sign of an hwaddr like those below (nvram show | grep hwaddr) which I see in the log - the first one (27:97) is one laptop, and I immediately switched to another (15:c0) to see what might happen. This was done on an as-vanilla-as-I-can-make-it setup:

Jul 31 16:12:30 wan: mac clone: [wan0_hwaddr] == [48:0f:cf:03:27:97]
Jul 31 16:12:36 rc_service: autodet 897:notify_rc restart_wan_if 0
Jul 31 16:12:36 kernel: Attempt to kill tasklet from interrupt
Jul 31 16:12:38 wan: mac clone: [wan0_hwaddr] == [d0:67:e5:39:15:c0]
Jul 31 16:12:38 kernel: Attempt to kill tasklet from interrupt
Jul 31 16:12:44 rc_service: autodet 897:notify_rc restart_wan_if 0
Jul 31 16:12:44 kernel: Attempt to kill tasklet from interrupt

After disconnecting from the first one, I see that nvram shows:
wan0_hwaddr_x=48:0f:cf:03:27:97

I always get the "ISP dhcp did not work" type of message.

I'm wondering if somehow this is confusing the modem and this address is being passed to it.

Any thoughts on what might be going on? Am I even likely on the right track? I'm going nuts!! (Fortunately my two other connections are static - and stable!)

Edit: I guess I should add that once - way back in this process - I accidentally did hit the Mac Clone option while using the 27:97 laptop.....
 
Last edited:
Hey,

It is possible that you changed the MAC cloning but you don’t need it actually.

We suggest you

  1. power off the cable modem first
  2. clear the Mac cloning setting
  3. power on the cable modem

And please let me know if the problem is solved or not. Thank you.
 
Apologies for the delay in responding!

I had copied the log etc to send to you, but managed to get hold of the folks where my modem is located and asked them to power-cycle it, pausing for a few minutes before restarting it. So far I can report that the news is good: the 68U picked up dhcp and has survived a few reboots. Have had no power outages yet (which is a complicating factor at times) so will continue to monitor and see if/when things get stuck again.

Do I understand then, that the issue is more of a modem/ISP one than a router one? Is there anything I can actually do about that (short of getting another public, static IP)?

Thanks for the assist!
 

Support SNBForums w/ Amazon

If you'd like to support SNBForums, just use this link and buy anything on Amazon. Thanks!

Sign Up For SNBForums Daily Digest

Get an update of what's new every day delivered to your mailbox. Sign up here!
Top