I needed to put my cable modem into bridge mode in order to be able to recieve port requests on port 80. My ISP (Kabel Deutschland) blocks port 80 requests otherwise. Since I want to set up my own server at home (in fact already did - works) I need to be able to reach it from outside.
Now, I have the cable modem in bridge mode, supposedly this is "pure bridge mode", only forwarding the traffic, no DHCP, wireless, firewall, etc.
I have a NetGear WNR2200 Router with OpenWRT 18.04 installed and tried to set this up for the past couple of days but I am turning in circles. To be frank honest, I have no idea what I am doing. I would be so glad if anyone here could give me a hand setting this up. I will gladly give more information!
So far I have (just reset the router and) added password protection to OpenWrt wireless net and connected a cable between LAN port 1 of the cable modem and WAN port of the NetGear router. I have also turned off the cable modem, let it off for a few minutes and turn it back on with only the NetGear router attached.
All I want to achieve is to be able to access the internet again and accept incoming http and ssh requests.
I think I can help with this. First you need this rule to enable remote ssh on your router. Note the 'xxxx', it should be a port of your choice for external purposes and change dropbear to let users access ssh only on LAN.
config redirect
option target 'DNAT'
option src 'wan'
option dest 'lan'
option proto 'tcp udp'
option src_dport 'xxxxx'
option name 'Allow Remote SSH'
option dest_port '22'
option dest_ip '192.168.1.1'
Then you need to setup DDNS to access your router remotely with a URL rather than your WAN IP. luci-app-ddns can help you with that. Please also consider to set up ssh-keys to enable this access rather than plain password.
Thank you for that, ahmar16! But I think this is one step too far down the road for me. I think the forwarding part is not going to be such a problem as setting up the network because I am more used to doing that (forwarding ports, ssh, general linux vibes). I just have no clue how to tell my OpenWRT router to become friends with my modem in bridge mode and let me access the internet.
Once that step is complete, setting up ssh and http forwarding shouldn't be such a problem (I hope). Or am I misunderstanding you and that redirect config would actually get me "out" to the internet again?
Oh hey, wait! I did another check right now - connect LAN cable from my laptop directly to the bridged modem and try accessing it through 192.168.100.1 - and did the power cycle with first attached device again afterwards (that seems to be necessary procedure) and now out of nowhere it just works!
Now I'll first go shopping groceries because this issue has kept me grounden the past days Afterwards I'll try your ssh config and can finally set up my network the way I want it.
Normally a "bridged" cable modem will pass the DHCP request from the router onto the cable, and a DHCP server at the cable company will answer it with a public IP address. Your router can then communicate in and out on that IP.
This also happens if you were to connect a PC directly to the modem-- though that is not a real solution since you can only have one PC, and all of its ports will be exposed directly to the Internet which is a major security risk.
The cable modem administration page will still be active at 192.168.100.1, but this is not involved in Internet access. It is merely a second address set up locally in the modem.
Afterwards I'll try your ssh config and can finally set up my network the way I want it.