Unable to use Omnia with Virgin Media cable router in Modem Mode

Turris Omnia
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I am a customer of Virgin Media cable in the UK. Their box has a thing called “Modem Mode”, which is where instead of being a wireless router, DHCP client etc. it just acts as a DOCSIS modem and passes through DHCP requests. It’s designed, they say, for you to use “your own router”. This should be exactly what’s needed to work with the Omnia.

However, it doesn’t. If I set my Virgin router into Modem mode, I can plug in my computer directly to pick up a DHCP lease from Virgin’s DHCP servers, but if I plug the Omnia in instead, it doesn’t do that (when configured to use DHCP for WAN). It reports “WAN port has no link”. Testing the connection on the DNS page shows it failing.

A couple of other people on this thread seem to be having similar problems:

I would log in via SSH and look at some log file to debug the failure, but… see my previous message in this forum.

Has anyone got this working? If so, how?

Gerv

2

Just a small question: Did you first power cycle your modem before plugging it into Turris Omnia?
Because normal behaviour of cable modems is to only give out 1 IP adress via DHCP. And if that was assigned already to your PC you don’t get another one until power cycle.

If that doesn’t help you should look into the LUCI webinterface and the System an Kernel Log.

1 Like
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And is there a link or not? Does the WAN LED shine? It looks like some Omnias are little bit picky regarding proper ethernet cables so perhaps try a different one.

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Yep, that should work. I have a Sagem Docsis modem configured in bridge mode and I had to reboot the modem so the Omnia could get the WAN IP address.

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I’m with Virgin Media.
Did a factory reset on the Turris Omnia. VM modem switched off for 5 mins then switched on. Once VM modem has completed sync I switched on the Turris Omnia. Connected to my Macbook Pro with a CAT6 cable + Thunderbolt adapter (same type of CAT6 cable used to connect VM modem to Turris). I start the Turris configuration. DHCP for IPv4… Seems to fail first time then try again with forwarding off… Tells me WAN connection is ok… Then fails to acquire time over NTP… So select same time as computer… Downloads all the updates… Install them… Tells me I need to reboot because of new Kernel… Reboot… And drums rolling nothing… Can’t even get an internal IP over DHCP… Tried to renew lease from the Macbook Pro… Nothing… Switched off the Turris (removed power cable). Wait a few seconds. Power back on… Same… Nothing. Can’t get a 192.168. ip for my Macbook Pro…

What now?
If this doen;t work with Virgin Media then it’s useless to me.

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Again, what do the LEDs show? Is there at least link light? It could be some hardware fault.

Also, connectivity issues between your computer and the Turris Omnia router are certainly not related to Virgin Media. It looks like related to this issue:
https://forum.test.turris.cz/t/intermittently-dead-ethernet-ports?source_topic_id=1687

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Yes the LED 2) Power is on. WAN 4) is flashing. LEDs 5) PCI1 and 2 are on.
As for the dead ethernet ports (possibly…) I didn’t unplug the CAT6 cable from Turris to Macbook to check this…

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Hi everyone,

Thanks for your help. The problem was indeed that I needed to reboot the Virgin Media box (set into Modem mode) after connecting the Turris - the person who speculated that it only gives out one DHCP address was probably right. So now it’s all working nicely :slight_smile:

So for anyone else with this problem:

  • Switch off the Omnia
  • Unplug all Ethernet cables from your VM box except the Omnia (into the Modem mode port)
  • Connect to VM box wifi or via Ethernet and use web interface to switch it to Modem mode
  • Watch it reboot
  • Wait until it has finished and the lights calm down
  • Power on the Omnia
  • Wait until it has fully booted
  • Check that you can access the Internet via a cable plugged into the Omnia

Gerv

9

Depending on what superhub you have, what you can do is log into to your superhub and turn it into modem mode, and let your Turris drive everything. then just power cycle your turris and should work, it will take all of about 10 minutes to accomplish, if you need to revert it you can go into 192.168.100.1 and then revert the changes on the super hub.

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This morning I switched off my Netgear R7000 and VM modem. Then swapped in the Turris Omnia (which had been configured yesterday) and powered on the VM modem and once properly synch’ed I powered on the Turris Omnia.
So far it’s been 90 mins of working pretty well. I’m connected to work over VPN for the day using 5Ghz WiFi (802.11ac/80MHz wide channel/channel:48) and my partner is connected to work using 2.4Ghz WiFi (802.11n/20MHz wide channel/channel:auto). Let’s see if it’s stable for the rest of the day :slight_smile:
NTP is ok. DDNS too.

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Mmm I’ve never used a VM hub in non-modem mode mate :slight_smile:
My routers have always driven everything.

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lol fair enough, just thought it needs to be mentioned. is your VPN through the turris or on your computer

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VPN on Macbook Pro.
Getting OpenVPN nicely setup on the Turris is another task! Not for work though just for private usage.

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yeah ive been trying to get openVPN to work and its not as easy as i initially expected, im using NordVPN, still on my list.