I'm new to OpenWrt so treat me with kid gloves please.
So, last night I was trying to get my Linksys WRT3200ACM working with OpenWrt and ran into a problem that I was unable to remedy. Here is the network architecture:
Inet Provider: Xfinity
Cable Modem: Ubee DVM3203B
Wouter: Linksys WRT3200ACM
Wouter LAN Addressing: 192.168.2.1/24
DHCP Pool: 192.168.2.100 – 150
So, I disconnected the WRT3200 from the modem and power cycled the modem to clear its DHCP.
I loaded the OpenWrt image and rebooted, then reconnected to the modem.
Logged in and set a password.
Then I applied this workaround from the WRT3200ACM device page ( https://openwrt.org/toh/linksys/wrt3200acm ):
“opkg remove kmod-mwifiex-sdio
wifi config > /etc/config/wireless
While tweaking some minor settings I noticed my LAN connect didn’t have internet access. So I went to Interfaces and saw that the WAN port had an address of 192.168.100.1(I think? I know it was 192.168.100.something). I restarted the WAN port and after a long time it got the same address. And then after more time it finally pilled a public address from Xfinity. And then after a few minutes of internet access, I would lose internet access but the public address would still show. Sometimes I would have to power cycle everything to get internet back only to lose it again.
Does anyone know what’s going on with this setup? Is there a WAN interface setting that I need to change to get the WRT3200 to work with the Ubee? I’ve never had this problem with the crappy Linksys software.
192.168.100.1 sounds like a docsis cable modem admin interface address.
Is the cable modem smart, a router? Or is it just a dumb one without routing?
Some modem lock to a single client MAC, so you might need to power off also the modem for a few minutes to get it to accept a new Mac (router's hardware address).
You might also check the OpenWrt system log, if there is any mention about "using random MAC" or similar. That would mean that the router invents a new random MAC at every reboot, which might confuse the modem if it is MAC-locked type.
Ps. Disabling the crippled radio2 mwifiex is wise, but should not affect your wired connectivity.
Regarding "losing internet access", make sure that you understand if the breakage is about the pc - router (WiFi?), or about router - modem/ISP.
Regarding WiFi, in OpenWrt context the wrt3200acm has difficulties with certain WiFi config (802.11w, 802.11r, wpa2/wpa3 mixed, wpa3), so be sure to use just basic wpa2 connectivity, and preferably debug via wired.
The cable modem is dumb. It only has enough smarts to give an attached router a public IP via DHCP. And ONLY one IP to one MAC address. And, yes, 192.168.100.1 is the private IP of the cable modem.
The modem was power-cycled prior to reattaching the wouter with the new software installed.
I forgot to look at the log (DOH!). Next time....
The loss of internet access is due to the WAN port IP acquisition problem. All testing was done via a wired connection.
That is a really old modem. Regardless, log into the modem to check that the cable signal is OK. There will be no IP issued from the cable company if the physical coaxial cable link is down.
Also some cable systems require more than a quick power cycle to forget your old router's MAC address. Try turning the modem off for 30 minutes then restarting it.
Well, the modem has been working fine with the same hardware when it had the linksys software on it, so I don't think it's a problem with the modem talking to Xfinity. And since I have fallen back to the Linksys software to get my internet working again, it is working fine now.
Also, whenever I power-cycle something I always give it time for the caps to discharge.
Is the WAN MAC the same with both firmwares? The way that OpenWrt assigns "factory" MACs to different interfaces may be result in a MAC that is one or two LSBs different than stock.
I don't know if the MAC is the same across firmwares. I need to do more testing.
But none of this explains why the WAN interface would get an IP in the 192.168.100.x range. The only thing the modem can lease is a public IP. 192.168.x.x is not public.