No connectivity but IP assigned and PC to modem working (United States, Comcast/Xnfinity)


#1

Hey! United States user here. My ISP is Comcast/Xfinity. Just got the Turris Omnia in the mail yesterday, super excited and hoping to get it working :slight_smile:

Problem:

I have a working modem (NETGEAR CM700, v1.02.02) at 192.168.100.1 and can connect to the Omnia (TurrisOS 3.10, Kernel 4.4.131) admin interface at 192.168.1.1. When I connect Omnia’s WAN port to the modem, and PC to Omnia’s LAN0, the PC is assigned IPv4 and IPv6 addresses but the Omnia fails WAN connectivity tests even though the WAN LED is on/blinking on the Omnia.

If I connect the PC directly to the modem (no Omnia in loop) then I can browse the internet without issue. So I believe the problem is between the Omnia and the modem.

I could complete the setup wizard, but ran into two problems in the process:

  1. Connectivity test fails (not sure what to enter for DUID? Still failing if I disable IPv6 in admin interface).


Post-Wizard connectivity fail (DNS tests also fail):

  1. Step 7 in the Wizard dumps an error page (reported to tech.support@turris.cz, I just reboot the router to continue to Wizard step 8 :wink:):

What I’ve Tried So Far:

  1. The above output is for TurrisOS 3.10. My router came with 3.8 installed and had the same connectivity problem so I flashed the 3.10 update via the steps described in this post, hoping that running the latest version would help - no luck.

  2. This post seemed to have a similar issue and fixed it by changing the Omnia’s internal IP. I tried setting the Omnia’s IP to 10.0.0.1 (what my ISP’s routers typically ship with as default) - no luck.

  3. Per my ISP’s requirement, I’m using a DOCSIS 3.0 modem. After digging around in the LuCI, I checked “Use broadcast flag” for the WAN interface (which is up/connected and receiving/sending data in the LuCI interface) - no luck:

  1. I tried calling my ISP, but they have zero clue about any of this and are not helpful. They said that if I can access the internet by connecting my PC directly the to modem then everything is fine on their end and I should just lease their modem/router combo for $11/month instead of using my own (no thanks!).

Any help is much appreciated, I am new to this but willing to troubleshoot as instructed!


#2

Is the TO actually getting a DCHP lease from the CM700? Can you ping the CM700’s ip from the TO (LUcI -> Network -> Diagnostics, or alternatively from the TO ssh?)


#3

Most DOCSIS ISPs will only allow one MAC address per customer for DHCP, so try to power-cycle both the cable modem and the router as that should make the DHCP server accepting any one MAC address again for a short time window.
Did you connect your PC before you connected the TO by any chance (that would explain why the PC works if directly connected).

Slight correction:
I believe it is actually not the cable head-end or CTMS that is relevant here, but the Cable Modem itself, see https://apps.cablelabs.com/specification/CM-SP-MULPIv3.1 Section 9.1.2. Thsat also explains wht rebooting the modem “solves” the issue.


#4

Hello,

We know about the bug, which is at Step 7 in the Wizard and it is fixed in Turris OS 3.10.1, which we released a few minutes ago.

Anyway, about the Connectivity test fails it’s caused that WAN port has no link. I’d recommend you to try different Ethernet cable from Netgear to the Omnia’s WAN port and let’s see if it will work afterward.


#5

That fixed it, thank you for the quick and spot-on response! :blush: Yes, I had connected the PC to modem first, before the TO, and had never reset the modem. Power-cycling both and connecting the TO to the modem first resolved everything:

  1. All connectivity (IPv4 and IPv6) tests pass.
  2. DNS and DNSSEC test pass.
  3. Can connect my smartphone to WiFi and fast.com shows 58 Mbps on my ISP’s 60 Mbps monthly plan, so everything is working as advertised.

#6

The suggestion by @moller0 fixed it for me, but thanks for your reply - will keep that in mind as a troubleshooting step in the future.


#7

Confirmed that the Step 7 issue is fixed in the 3.10.1 wizard, thanks! Per the above, everything is working perfectly for me now.