AC68u router reporting wrong WAN IP

[johnlepdx]

Hey SNB,

I'm a noob at this and I don't know how to address/ fix the issue. My internet has been acting kind of funky and my ISP said that comcast technicians were plugging their equipment into my buildings switch. It caused intermittent issues and after a long phone call with my ISP, they supposedly fixed it. My VOIP service is unstable. and I need it for school. My current issues are that

1. Router reports a completely different IP from my service. My router reports a comcast IP but when I do a speed test or go to a website to grab my IP, it reports the correct IP
   1. 100.65.X.X (COMCAST) vs 64.112.x.x (ACTUAL IP)
2. CONNMON reports low ping/ jitter but internet quality is between 41-45% consistently
3. pinged 8.8.8.8 from the router
   1. --- 8.8.8.8 ping statistics ---
      379 packets transmitted, 379 packets received, 377 duplicates, 0% packet loss
      round-trip min/avg/max = 7.570/7.874/12.027 ms

Hardware:
AC68U - router is acting as a wired router (disabled wireless) w/ diversion, skynet, unbound, and various scripts
AC68U - wireless access point
Linksys - wireless access point
All the access points are directly wired in.

Is there anyway I can force my router to just pull from my actual ISP and force the traffic that way instead of using the comcast IP. My downloads are going fine and everything seems like it works except for my VOIP service. I don't do any heavy uploading (or usually don't). Is this an issue I can solve on my side or do I have to talk to my ISP. Thanks ahead of time for the help!

 

[ColinTaylor]

100.65.X.X is a CGNAT address. In other words 64.112.x.x would be the public IP address of your ISP's servers. This IP address is shared with multiple customers by using CGNAT, so each customer gets their own private 100.65.X.X address.

CGNAT causes problems with services that require unsolicited incoming connections, like some multiplayer games and VoIP. To resolve this problem you need your ISP to assign you a real public IP address rather than a CGNAT address.

CGNAT in itself shouldn't have any bearing on speed or packet loss. But the fact that your ping is reporting duplicate packets implies that there is a serious fault in the network path somewhere. Trying pinging your router's IP address to determine whether the fault lies within your LAN or on the other side of the router.

 

[Mr Tvardovsky]

Dear SNB Experts,

I have discovered I’m facing the same CGNAT issue when I tried to set up an OpenVPN server on a DSL-AC68U at my in-laws’. The router is placed behind an ISPs bridged modem and running the latest @GNUton’s stable firmware. I would like to be able to access it remotely to troubleshoot for them when needed. Unfortunately DDNS fails to work correctly - the respective GUI tab detects the CGNAT address and warns me that I’m behind the double NAT. In consequence, the VPN server cannot generate a working certificate (and gives me another double NAT warning).

Is there any workaround other than getting a ‘real’ public IP from the ISP? I’m afraid their first line help desk is rather hopeless.

 

[ColinTaylor]

Install TeamViewer on one of their PCs. Then get them to run it when you need access to their network.