topic Re: open ports with john lewis broadband in Tech Help - Software/Hardware etc

open ports with john lewis broadband

iamwill — Thu, 29 Sep 2022 09:43:42 GMT

I've got Zyxel VMG3925-B10C router with my John Lewis Broadband contract (plus net is the upstream). I've spent the best part of a day trying to open ports 5228, 5229, 5230 and 443. There's zero support from JL and almost no info on the router. Having tried all the usual settings to open the port I can only conclude that the ports are blocked by the isp. Can anyone offer any insight which might help?

Thanks loads

Will

Re: open ports with john lewis broadband

MisterW — Thu, 29 Sep 2022 10:05:24 GMT

@iamwill port forwarding for the VMG3925-B10C can be found from the Network Setting->NAT menu

Are you trying to open ports for inbound or outbound connections ?

Outbound connections are not blocked at all.

For inbound connections you must forward the port to a specified connected device.

Re: open ports with john lewis broadband

dvorak — Thu, 29 Sep 2022 11:10:46 GMT

Moderators Note

This topic has been moved from Broadband to Tech Help

Re: open ports with john lewis broadband

iamwill — Thu, 29 Sep 2022 11:17:29 GMT

Hi MisterW

Thanks for the reply, I've set up a static ip for the destination computer (Network Settings >> Home Network >> Static DHCP) and then forwarded the ports to the static IP (Network Settings >> Home Network >> Nat >> Port Forwarding).

I've tried loads of different setting like disabling firewall, DMZ host.

Thanks loads for any further ideas.

Will

Re: open ports with john lewis broadband

MisterW — Thu, 29 Sep 2022 11:42:16 GMT

That should work fine. I've used one of these routers in the past and had port forwarding for a VNC server working. You should have the Firewall on LOW and make sure there's nothing in the DMZ

You won't see the port open unless the destination computer is running and has an application or service listening on the ports.

Re: open ports with john lewis broadband

Townman — Thu, 29 Sep 2022 14:19:26 GMT

Do JLP accounts have an ISP 'side' firewall similar to that of native Plusnet users?

If the account's firewall options are enabled, connections to the ports might be blocked long before getting anywhere near the router.

Re: open ports with john lewis broadband

MisterW — Thu, 29 Sep 2022 14:42:43 GMT

Do JLP accounts have an ISP 'side' firewall similar to that of native Plusnet users?

@Townman I did think about that, but I can;t see any reference to one in the JLP Help & Support

but that does make me think @iamwill is there any firewall on the destination computer that may need configuring ?

Re: open ports with john lewis broadband

Townman — Thu, 29 Sep 2022 15:01:30 GMT

@MisterW wrote:

... make sure there's nothing in the DMZ

You won't see the port open unless the destination computer is running and has an application or service listening on the ports.

Putting the "target" PC into the DMZ as a test would help to eliminate ...

Issues with an ISP's service side firewall
Issues with a local fire wall on the target PC

Subsequent to establishing an external connection to the target PC with it in the DMZ, it can then be removed from the DMZ and attention focussed on addressing the port forwarding rules. I suggest that this problem needs layering.

This resource might be helpful - GRC | ShieldsUP! — Service Ports Probe - see the section entitled "Service Ports Scan Application Guide (Cool things you can do with our Service Ports Probe)"

Re: open ports with john lewis broadband

iamwill — Thu, 29 Sep 2022 15:35:43 GMT

Thanks Chaps!!!

I've disabled the firewall on my mac so this shouldn't be a problem.

I made the target PC into a DMZ and this didn't change a thing, no ability to reach the target mac

I ran the ShieldsUP! test and got the following result - "THE EQUIPMENT AT THE TARGET IP ADDRESS
DID NOT RESPOND TO OUR UPnP PROBES!" I'm not sure what this means though....

How can I find out if JL have a firewall ISP side? Having tried everything it feels like this is likely.

Thanks again for all the help!

Will

Re: open ports with john lewis broadband

bobpullen — Thu, 29 Sep 2022 16:07:45 GMT

There is no server side firewall on JL.

What exactly are you forwarding ports to?

As others have mentioned, there will need to be a service running/listening on said port in order for it to be shown as open.

Can you access the service locally on your own network using the ports in question?

Re: open ports with john lewis broadband

Townman — Thu, 29 Sep 2022 17:03:49 GMT

Shields up only tests the lower 1028 ports automatically - you will need to use the specific port tests to inspect 5228-5230. Put 5228-5230 into the text box and press entre.

What are you trying to run - Google Talk? See here.

Why do you think you need to open these explicitly? (At the risk of teaching you to suck eggs, but for the avoidance of doubt...) You only need to open ports for INBOUND connections. What application are you HOSTING? Port 443 is HTTPS and infers a hosted webserver.

If this is related to Google Talk, I think that those are OUTBOUND ports - see here https://serverfault.com/a/42104

Re: open ports with john lewis broadband

Champnet — Thu, 29 Sep 2022 18:31:33 GMT

Part of a routers job is to transfer requests from a known external port to a defined port on an internal device, It shouldn’t matter that the internal device doesn’t exist in which case there will be no response. Given the problem, I know some ISPs block certain ports, I’d be asking John Lewis if they had any blocks on any ports.

It would be helpful if we knew which port(s) were causing the OP’s problem.

Re: open ports with john lewis broadband

bobpullen — Thu, 29 Sep 2022 19:27:55 GMT

John Lewis Broadband does not intentionally block any of these ports out on the network.

Re: open ports with john lewis broadband

Champnet — Thu, 29 Sep 2022 19:37:43 GMT

Thanks, I'll accept that all 65K ports are open....