topic Re: Cannot access server by DynDNS menmonic from LAN side. in Broadband

Cannot access server by DynDNS menmonic from LAN side.

kdmcm — Mon, 07 Feb 2022 18:34:27 GMT

I've set up DynDNS on my FAST5364. It works fine: I can access my server from outside my home.

However, for debug purposes, I'd like to be able to access my server via the DynDNS mnemonic address from inside my home, but am unable.

nslookup (from inside my LAN) returns my correct WAN side IP address.

I can't find any NAT settings on my dashboard. I believe the setting I need to fiddle with is "hairpin NAT".

Is this something you can help with, please?

Thanks.

Re: Cannot access server by DynDNS menmonic from LAN side.

Anonymous — Tue, 08 Feb 2022 07:21:32 GMT

Hi,

@KeithFrench - Is this something that you would be able to provide advice on please?

Thanks

Re: Cannot access server by DynDNS menmonic from LAN side.

KeithFrench — Tue, 08 Feb 2022 11:39:32 GMT

Hi @kdmcm, @Anonymous has asked me to help with your DDNS problem.

You won't be able to access locally connected devices using your DDNS domain like that. All TalkTalk routers block NAT loopback (where traffic goes from your LA N out to the internet & back in again) as they deem that a security risk. The only way to access local devices from other local devices is to use their 192.168.1.x address as the destination IP address.

There are no NAT settings on the dashboard, port forwarding is elsewhere in the router's GUI. If you want any help with this, just give me the make/model of the router & the TCP or UDP ports that you want to forward & I will help.

Re: Cannot access server by DynDNS menmonic from LAN side.

kdmcm — Tue, 08 Feb 2022 12:53:53 GMT

Ah. That's irritating.

I really wish we could get access a the full featured firmware, rather than the nanny-state version. I know exactly what I want to do. Most irritatingly, the reason I want to disable hairpin NAT is to debug the SSL certificate code in a server I'm playing with, in order to make my forwarded port more secure! I'll do it by local IP.

Surely it's up to me if this is a security risk? I mean, having a WAN-facing router hanging off my home network at all is a security risk!

Anyway, it's hardly your call. Thank you for your input, though.