Posted: Wed Sep 21, 2022 23:38 Post subject: Can't connect after cable co. changed modem settings
I've had a Netgear R7800 router running off a cable modem for a couple years, using an older firmware: v3.0-r40559, simply because I didn't want to break things by updating.
I'm not a network expert so struggle with some of this.
The cable co. modem is set to bridge mode and my router would get via DHCP an IP number and gateway in the 192.168.100. range. My router was set to give the LAN 192.168.1.0 addresses. Then we had a fire in town that toasted some cables and caused a power outage. The cable co. had to do some rewiring. When they were finally back online, I couldn't connect to the internet. Investigating, it looked like the modem was now serving addresses in the 206.174.22.0 range for IP and gateway. I finally was able to connect by configuring the router with a static IP address of that range using the addresses from renewing my DHCP. For one day everything worked, though I knew it was temporary since that modem would eventually change the served IP address. Then I started getting dropped internet.. would work for a bit then drop out. The next day was a bit worse. If I go back to the cable modem as WiFi router, bypassing my router, it works fine. I could not get any internet by configuring the router WAN as DHCP or now even as static.
The netgear router is set as gateway. I tried setting the router with DHCP. LAN was set with IP address as 192.168.1.4 and gateway 192.168.1.1.
I'm on linux (desktop) and android phone in case there is some investigating I could do there. Wife on MAC stuff. She works from home so I don't get much opportunity to turn off internet (which happens when I switch the modem from gateway to bridge) and try different things with the router. I'm also wondering if the router suffered damage in the power outage, as it isn't on any kind of power protection. The outage was just a quick off by the utility co. to protect the fire fighters, then a quick on.. not a brown out. The last router I had blew a condenser that I was able to detect (swollen) and replace with crude soldering. Haven't opened this one up yet.
Cable company tech support isn't much help - they just don't have much experience.
plus their modem works fine so it is basically my problem.
You should probably leave your router set to DHCP on the WAN side. Setting your WAN IP to a static address will eventually stop working for sure (after 24hrs?), you are correct there. If you are actually getting an IP address in the 206.174.22.0 subnet, that is probably correct. What are you using for DNS addresses? Try setting your DNS to 8.8.8.8 as primary and 1.1.1.1 as secondary. Your gateway should not be 192.168.1.1 on your router, but maybe you were not clear enough here. The gateway should probably be within the assigned IP subnet (206.174.22.x). So, say your router is assigned 206.174.22.1, your gateway will probably be 206.174.22.x as well. Sounds like a misconfiguration of your router to me. Posting some screen grabs may be helpful. Also, you really should update your firmware to the latest version. r40559 is way to old to be safe to use.
Upgrade, reset and start over. That is your best bet at this point I believe. _________________ Linksys EA8500 (Internet Gateway, AP/VAP) - DD-WRT r53562
Features in use: WDS-AP, Multiple VLANs, Samba, WireGuard, Entware: mqtt, mlocate
Wireless 5ghz only
Netgear R7800 (WDS-AP, WAP, VAP) - DD-WRT r55779
Features in use: multiple VLANs over single trunk port
Linksys EA8500 WDS Station x2 - DD-WRT r55799
Netgear R6400v2 WAP, VAP 2.4ghz only w/VLANs over single trunk port. DD-WRT r55779
OSes: Fedora 38, 9 RPis (2,3,4,5), 20 ESP8266s: Straight from Amiga to Linux in '94, never having owned a Windows PC.
Current release is 50176. You'll want to download and flash the
09-15-2022-r50176/netgear-r7800/dd-wrt-webupgrade.bin
and reset and start fresh. _________________ "The woods are lovely, dark and deep,
But I have promises to keep,
And miles to go before I sleep,
And miles to go before I sleep." - Robert Frost
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Posted: Thu Sep 22, 2022 6:30 Post subject:
Indeed upgrade and *after* upgrade reset and put settings in manually.
But actually it should work out of the box after a reset (it is then on Automatic DHCP and Gateway and local DNS are set (and should be kept) at 0.0.0.0 (=automatic) )
What are you using for DNS addresses? Try setting your DNS to 8.8.8.8 as primary and 1.1.1.1 as secondary. Your gateway should not be 192.168.1.1 on your router, but maybe you were not clear enough here. The gateway should probably be within the assigned IP subnet (206.174.22.x). So, say your router is assigned 206.174.22.1, your gateway will probably be 206.174.22.x as well. Sounds like a misconfiguration of your router to me. Posting some screen grabs may be helpful.
Thanks so much! Firmware has been updated to the latest now. As for DNS, the WAN DHCP provided the ISP's DNS servers if I remember right when trying to use DHCP, which I was doing when everything pre-outage was working fine. Back then I had under Network Setup I had Local IP Address as 192.168.1.6/24, Gateway as 192.168.1.1, and local DNS 192.168.1.6. Somehow that all worked. When trying it after the outage it didn't work.. so that's when I tried a static setup for WAN and there I did use the ISP provided gateway of 206.174.22.129. Hopefully it is a misconfigure on my part. I'll try for some screen shots of configs.. It is difficult turning off the internet to try when my wife works at home.. but I get some time here and there. Also a pain to reset my desktop - I have a home NAS setup with several different network shares.. I have to unmount all those. Then change my fstab file to comment them all out. Then I have been editing my /etc/conf.d/net file to comment out my static ip address and gateway ( I could just leave this as dhcp for now) and then I do a "/etc/init.d/net.enp2s0 restart", which takes a bit of time as it still searches a bit for network shares. There's probably an easier way I'm not aware of to switch from 192.168.1.0 to the 192.168.0.0 network, which the modem is on.
Indeed upgrade and *after* upgrade reset and put settings in manually.
But actually it should work out of the box after a reset (it is then on Automatic DHCP and Gateway and local DNS are set (and should be kept) at 0.0.0.0 (=automatic) )
If not power down your modem and router, power up your modem after 5 minutes and after the modem is powered up power up your router.
Thanks for the tips! I'll give this another shot.. I'll do as you say. I'll try for some screen shots of the config if it doesn't work.
There's probably an easier way I'm not aware of to switch from 192.168.1.0 to the 192.168.0.0 network, which the modem is on.
You shall not use the same sub-net as the one your modem is on.
Thanks for the reply. My regular LAN when on the Netgear router is 192.168.1.x with printers and NAS configured. Now that my router is probably misconfigured, I have to be on the ISP's modem which uses 192.168.0.x for the LAN DHCP. So if I want to log into the modem when using it as a router, my computer has to be on that .0.x. subnet. Or to switch if from gateway to bridge mode to start using the Netgear. The Netgear router defaults to the .1.x subnet, so to log into it, I have to be on that subnet. That's what I was talking about. The modem serves up as a DHCP interface to the router with the 206.174.22.x or similar. Hope this makes sense.
Thank you for your patience. I'll have to digest the contents of the link for a bit. Though the first thing it says is to hook the modem directly up to the computer to find what ip address it is throwing. So I hooked my raspberry pi up to the LAN port on the modem after switching the modem to bridge mode and then booting the RPI. It couldn't find an ip address when I issued ifconfig. It returned the 169.254.123.126 address. I'll try again later with my desktop.
Thoroughly confused now. I have run my own router for over a decade I'm sure - so I have what I thought was a rudimentary understanding.
I plugged my computer directly into the ISP's modem which was set to bridge mode and restarted my computer's network interface and it said:
Code:
enp2s0: soliciting a DHCP lease
enp2s0: offered 206.174.22.31 from 209.165.131.102
enp2s0: probing address 206.174.22.31/25
enp2s0: leased 206.174.22.31 for 86400 seconds
enp2s0: adding route to 206.174.22.0/25
enp2s0: adding default route via 206.174.22.1
* Stopping ntpd ... [ ok ]
* Starting ntpd ... [ ok ]
forked to background, child pid 16760 [ ok ]
* received address 206.174.22.31/25
Ifconfig reported an IP address of 206.174.22.35. And I could ping webpages.
Then plugged into the router and plugged that into the modem. restarting net said:
Code:
enp2s0: soliciting an IPv6 router
enp2s0: rebinding lease of 206.174.22.31
enp2s0: NAK: wrong network from 192.168.1.6
enp2s0: message: wrong network
* Stopping ntpd ... [ ok ]
* Starting ntpd ... [ ok ]
enp2s0: soliciting a DHCP lease
enp2s0: offered 192.168.1.111 from 192.168.1.6
enp2s0: probing address 192.168.1.111/24
enp2s0: leased 192.168.1.111 for 86400 seconds
enp2s0: adding route to 192.168.1.0/24
enp2s0: adding default route via 192.168.1.6
forked to background, child pid 17646 [ ok ]
* received address 192.168.1.111/24
and I could not get internet.
Reset the ISP modem to Gateway (from bridge mode) and kept my computer plugged into the router, which was still plugged into the LAN port on the modem. And I have internet. So the router is working off the modem not set to bridge mode.
I didn't restart the router so maybe that is partly to explain. I guess I better restart it and see what happens.
Do you get a 206.174.22.x address on the router when plugged into the modem?
Is the router set to wan dhcp?
Restart the modem, then plugin the router.
Can you ping anything on the Internet from the router?
Yes, router is set to WAN dhcp.
I unplugged the modem, disconnected router from it, unplugged router. Then let modem boot back up. Then plugged router back into modem LAN port and let it boot up.
The internet seems to be working fine. So the modem is set to Gateway, the router is set to Gateway. The modem provides working WiFi/eth on the 192.168.0.x lan, and the router provides working Wifi and ethernet on the 192.168.1.x lan.
The instructions provided with the modem from the ISP state that to use your own router, set it to bridge mode. I had that working for a couple years. But now (after the power outage last week) with it not set to bridge mode, it seems to be working for the home router.
I can live with this I guess. As long as I'm connecting with my router.
