Portforward suddenly not working

[Nalyd217]

Below is my issue, it's just weird because I started in a live chat on Reddit.

Me> Friends can't join a Minecraft server I'm trying to set up (don't judge). I've done this many times in the past without issue but now no one can join. The only thing that has changed for me since the last time that someone has tried to join a server hosted by me is that I have a new modem now.

RyRYs> I judged

Me> We're trying to do a hardcore like PBG did on YouTube, but yeah no one can join

RyRYs> Sounds like your modem is not port forwarding / firewall is blocking the connections to me

Me> I've tried all of that, the port was still forwarded from before, and I deleted it and re-did it to make sure. I added the port (25565) to my firewall as an "input rule" so that in theory it can get in, also I've tried disabling my firewall all together. Still nothing has worked though

I'm just looking for anything to try at this point. I'm just kind of frustrated because it's always worked flawlessly in the past and now suddenly (because of my modem I'm assuming) it just won't work. The only other thing that's different from before is that now when I launch the server, in the console it gives me some "illegal reflective access" warnings.

 

[Hiitchy]

So if there's a new modem, are the previous port forwarding settings applied in there too? Or is it just set to bridge mode and your router handles all requests to connect to the network?

[Windows7ge]

Are you connecting using a domain or an IP address? Public IPs based on ISP are prone to change. Did you check if the IP you're using is the current one your router has?

[Nalyd217]

Just now, Hiitchy said:

So if there's a new modem, are the previous port forwarding settings applied in there too? Or is it just set to bridge mode and your router handles all requests to connect to the network?

I'm assuming the latter? I've checked the portforward in my router like a dozen times and everything's correct, and from what I can tell I can't access my modem in any way. 

[Nalyd217]

2 minutes ago, Windows7ge said:

Are you connecting using a domain or an IP address? Public IPs based on ISP are prone to change. Did you check if the IP you're using is the current one your router has?

Yup, I gave my friends the current IP and I checked it before every time they tested to make sure it didn't change.

[Windows7ge]

3 minutes ago, Nalyd217 said:

Yup, I gave my friends the current IP and I checked it before every time they tested to make sure it didn't change.

Are you using a router/modem combo or are you using two separate devices? If your routers WAN port has a private IP you'll need to setup port forwarding on both the Modem and the router. Or, like Hiitchy mentioned, bridge mode in which the WAN interface on the router would be your public IP by disabling the router function on the modem. This is assuming the modem doubles as a router. It might not.

 

You can also use an online service to check if the desired port is open. If it's not then the modem is likely the culprit.

[Nalyd217]

5 minutes ago, Windows7ge said:

Are you using a router/modem combo or are you using two separate devices? If your routers WAN port has a private IP you'll need to setup port forwarding on both the Modem and the router. Or, like Hiitchy mentioned, bridge mode in which the WAN interface on the router would be your public IP by disabling the router function on the modem. This is assuming the modem doubles as a router. It might not.

 

You can also use an online service to check if the desired port is open. If it's not then the modem is likely the culprit.

My router and modem are separate. The modem is just a "dumb" cable company modem and the router is a Linksys EA9200. I also just checked the port checker thing and it says that the port is not open. 

 

Edit: How would I check for the WAN thing?

Edited April 11, 2018 by Nalyd217

[Windows7ge]

1 minute ago, Nalyd217 said:

the port is not open. 

If the modem is the only thing that changed in the config since the last successful connection then it is the culprit.

 

The modem has to have a configuration menu at the default gateway address (usually 192.168.0.1, you're probably on the 192.168.1.0 network) in there you can either forward the port to the WAN interface of the router or enable bridged mode and configure the public IP on the routers WAN interface.

 

Personally I'd do the latter, it'll make for less headache in the future.

[Nalyd217]

1 minute ago, Windows7ge said:

If the modem is the only thing that changed in the config since the last successful connection then it is the culprit.

 

The modem has to have a configuration menu at the default gateway address (usually 192.168.0.1, you're probably on the 192.168.1.0 network) in there you can either forward the port to the WAN interface of the router or enable bridged mode and configure the public IP on the routers WAN interface.

 

Personally I'd do the latter, it'll make for less headache in the future.

Where would I go to enable bridged mode? (Modem is an Arris TM 1602 if that helps)

[Windows7ge]

12 hours ago, Nalyd217 said:

Where would I go to enable bridged mode? (Modem is an Arris TM 1602 if that helps)

You need to connect to the network the modem is broadcasting. In other words, unplug the router from the modem and plug that cable into your computer. Wait for an IP, check what the default gateway is (usually 192.168.0.1). Then login to the modem. From there you can do what I wouldn't do which is port forward to the routers IP or find the bridge mode option. It may also be called NAT (Network Address Translation) or NAT Mode. From here choose bridged. Connect the cable back to the router. Then go into the routers WebUI and manually change the WAN interface IP/subnet mask/default gateway for both IPv4 and IPv6 (IPv6 is a bit different) to match what the modems was. From there your modem is now irrelevant when it comes to opening ports or anything else and everything will be handled by the router. Just make sure firewalls are enabled on it because now that's your shield.

 

If it worked you should then be able to see the ports are open. If not then something needed to be changed on the modem though in bridged mode port forwarding shouldn't be needed

[Nalyd217]

5 minutes ago, Windows7ge said:

You need to connect to the network the modem is broadcasting. In other words, unplug the router from the modem and plug that cable into your computer. Wait for an IP, check what the default gateway is (usually 192.169.0.1). Then login to the modem. From there you can do what I wouldn't do which is port forward to the routers IP or find the bridge mode option. It may also be called NAT (Network Address Translation) or NAT Mode. From here choose bridged. Connect the cable back to the router. Then go into the routers WebUI and manually change the WAN interface IP/subnet mask/default gateway for both IPv4 and IPv6 (IPv6 is a bit different) to match what the modems was. From there your modem is now irrelevant when it comes to opening ports or anything else and everything will be handled by the router. Just make sure firewalls are enabled on it because now that's your shield.

 

If it worked you should then be able to see the ports are open. If not then something needed to be changed on the modem though in bridged mode port forwarding shouldn't be needed

I’ll look into that tomorrow but I gotta go get some sleep for now. I found this while looking around though, so can I even access my modem? https://community.eero.com/t/36lx7y/does-a-cable-modem-without-wifi-need-to-be-set-to-bridge-mode

[Windows7ge]

11 hours ago, Nalyd217 said:

I’ll look into that tomorrow but I gotta go get some sleep for now. I found this while looking around though, so can I even access my modem? https://community.eero.com/t/36lx7y/does-a-cable-modem-without-wifi-need-to-be-set-to-bridge-mode

If you port forwarded on the router but an online port tester still says it's closed then the modem is likely the culprit. I don't have much to do today so I'll put some time into researching the modem and see what configuration options it has. I know firmware updates can change how a device behaves. If that comment is old it may no longer be accurate.

[Windows7ge]

@Nalyd217 There does not appear to be a whole lot of information available on the WebUI of that modem. You're going to have to log in to it and find the settings for port forwarding or bridged mode. I'm going to assume whoever setup the old modem did all of this before they left but this wasn't done this time. The internet will work either way but port forwarding won't.

[Nalyd217]

@Windows7ge So how would I log into it, or is that the part you’re not sure on?

[Nalyd217]

@Windows7ge SO I figured it out and I literally had to change one number in and ip address... kmn

[Windows7ge]

1 hour ago, Nalyd217 said:

@Windows7ge SO I figured it out and I literally had to change one number in and ip address... kmn

When you plug directly into the modem it'll tell you the default gateway IP in CMD with the ipconfig command.

 

If all you want is for the port forwarding to work find those settings in the modem and forward the port to the IP assigned to the WAN interface of your router.

or

Bridged mode etc etc I said it before.

[Donut417]

17 hours ago, Nalyd217 said:

@Windows7ge So how would I log into it, or is that the part you’re not sure on?

You modem doesnt have a router or firewall built in so you cant really do nothing there. You CAN log in to the modem via 192.168.1.100 as long as your ISP did not lock you out. All you can do in your modem is check your signal quality and read logs. There should be no configuration you can do. Only ISP's can configure the modem. 

14 hours ago, Windows7ge said:

When you plug directly into the modem it'll tell you the default gateway IP in CMD with the ipconfig command.

 

If all you want is for the port forwarding to work find those settings in the modem and forward the port to the IP assigned to the WAN interface of your router.

or

Bridged mode etc etc I said it before.

The OP has a standard digital voice modem. It has no router built in. I checked it on Amazon myself. So there is no port forwarding that can be done there. 

[Windows7ge]

18 minutes ago, Donut417 said:

The OP has a standard digital voice modem. It has no router built in. I checked it on Amazon myself. So there is no port forwarding that can be done there. 

If this is the case I'm to assume something went wrong with the port forward on the router. OP says the modem was the only thing that has changed and yet online tests say the port he opened is closed. I'm not certain what else it could be at this point. Unless theirs a unique identifier he's missing with the new modem but I haven't any clue what that'd be.

[Donut417]

9 hours ago, Windows7ge said:

If this is the case I'm to assume something went wrong with the port forward on the router. OP says the modem was the only thing that has changed and yet online tests say the port he opened is closed. I'm not certain what else it could be at this point. Unless theirs a unique identifier he's missing with the new modem but I haven't any clue what that'd be.

My guess its a bug in the firmware. Generally when your router goes to shit like that its a software problem. Maybe a firmware upgrade will fix but who knows. 

[Windows7ge]

55 minutes ago, Donut417 said:

My guess its a bug in the firmware. Generally when your router goes to shit like that its a software problem. Maybe a firmware upgrade will fix but who knows. 

I proposed that his IP changed but he verified that the one he's testing with is the correct one. So...last thing I can think of is that his computer (the server) doesn't have a static IP, it changed and now the port forward is pointing to an IP that isn't the servers. Even then I think a online port tester would still show positive so I'm thinking that's not it.

 

Maybe a software/firmware conflict between the modem & the router? So the port isn't properly being read? Even then I'd think his internet wouldn't work at all if that were the case.