Another NAT-Loopback Saga

mattius001 · ‎27-12-2022

This post is my last ditch attempt before replacing the EE Smart hub.

Im trying to circumvent nat-loopback but having little success,

I've setup a local DNS server, and setup a static route for the problematic server ( synology NAS ),

Interestingly this works when i set the DNS on windows to the local DNS server and the ddns is routed to the internal ip, but when i set the DNS server in the EE Smart hub settings it fails to route it, its not even hitting the DNS server.

What i really don't understand, is according the the smart hubs own configuration, anything that doesn't get blocked by the firewall rules ( firewall is disabled ), will be routed to the DMZ host ignoring the NAT. Yet that isn't true, because it is blocking this.

Is there something im missing? or is replacing the EE smart hub the only option?

It really is a massive omission to not enable nat loopback on these routers, using an internal address is not really a convenient option, you are constantly having to change logins for applications depending on whether you are home or away, setting the DNS to a local one is quite an extreme option not really available to most users.

XRaySpeX · ‎28-12-2022

@bobpullen wrote:

What does the area of the hub manager look like where you can assign custom DNS? What menus do you navigate through to get to it? Just trying to reinforce my belief that the DNS is supposed to be dished out by the DHCP server.

The DNS has nowt to with the DHCP & its leases. They are set for the whole time:

If you think I helped please feel free to hit the "Thumbs Up" button below.

To phone EE CS: Dial Freephone +44 800 079 8586 - Option 1 for Mobile Phone & Mobile Broadband or Option 2 for Home Broadband & Home Phone

ISPs: 1999: Freeserve 48K Dial-Up > 2005: Wanadoo 1 Meg BB > 2007: Orange 2 Meg BB > 2008: Orange 8 Meg LLU > 2010: Orange 16 Meg LLU > 2011: Orange 20 Meg WBC > 2014: EE 20 Meg WBC > 2020: EE 40 Meg FTTC > 2022:EE 80 Meg FTTC SoGEA > 2025 EE 150 Meg FTTP

mattius001 · ‎28-12-2022

Yeah releasing the DNS and renewing it had no effect.

Primary DNS is pointing to my local DNS ( now .200 ) I've tried everything in the secondary ( it doesn't like being blank ) currently set to an unknown ip address, have tried both pointing to my local DNS, but still nothing.

Looking at the clients, they all have the smart hub as their DNS

Doing an nslookup, its looking up using the Smarthub DNS, not my custom DNS, which is working

bobpullen · ‎28-12-2022

Thanks @XRaySpeX - that addresses that aspect then.

Differs to the Smart Router that assigns custom DNS via DHCP, rather than assigning to the WAN connection: -

XRaySpeX · ‎28-12-2022

@bobpullen wrote:

If you do an ipconfig, what DNS server addresses is assigned to the active Windows network interface?Presumably the router IP still? It should be the IP of your local DNS server.

It will be the router's IP:

Windows IP Configuration

Host Name . . . . . . . . . . . . : XRay's PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : XRayGroup
home

Ethernet adapter XRay Ethernet:

Connection-specific DNS Suffix . : XRayGroup
Description . . . . . . . . . . . : Realtek PCIe GBE Family Controller
Physical Address. . . . . . . . . :
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : (Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.1.10(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 16 December 2022 09:00:53
Lease Expires . . . . . . . . . . : 03 February 2159 21:40:51
Default Gateway . . . . . . . . . : 192.168.1.2
DHCP Server . . . . . . . . . . . : 192.168.1.2
DHCPv6 IAID . . . . . . . . . . . : 230718673
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-D6-7B-CF-C0-7C-D1-A1-2A-D1
DNS Servers . . . . . . . . . . . : 192.168.1.2
NetBIOS over Tcpip. . . . . . . . : Enabled

If you think I helped please feel free to hit the "Thumbs Up" button below.

To phone EE CS: Dial Freephone +44 800 079 8586 - Option 1 for Mobile Phone & Mobile Broadband or Option 2 for Home Broadband & Home Phone

ISPs: 1999: Freeserve 48K Dial-Up > 2005: Wanadoo 1 Meg BB > 2007: Orange 2 Meg BB > 2008: Orange 8 Meg LLU > 2010: Orange 16 Meg LLU > 2011: Orange 20 Meg WBC > 2014: EE 20 Meg WBC > 2020: EE 40 Meg FTTC > 2022:EE 80 Meg FTTC SoGEA > 2025 EE 150 Meg FTTP

mattius001 · ‎28-12-2022

So it does look like the EE Smart Hub is ignoring the DNS server settings

bobpullen · ‎28-12-2022

@mattius001 - so, if the Smart Hub is only capable of attaching custom DNS to the PPP interface, and that's still not routing the internal traffic correctly for you, then there could be an alternative solution.

I don't know what model of Synology NAS you are using, but does it have the ability to act as a DHCP server as this suggests?

If it does, then you could disable DHCP on the Smart Hub (assuming it allows this), enable DHCP on your NAS (assuming it stays powered up all the time), and then configure the DHCP parameters on the NAS to issue itself as the primary/secondary DNS server addresses as part of the DHCP lease.

XRaySpeX · ‎28-12-2022

@bobpullen wrote:

Differs to the Smart Router that assigns custom DNS via DHCP, rather than assigning to the WAN connection: -

It doesn't really! They are just configured on the same page (everything to do with IPv4) but are not otherwise connected.

If you think I helped please feel free to hit the "Thumbs Up" button below.

To phone EE CS: Dial Freephone +44 800 079 8586 - Option 1 for Mobile Phone & Mobile Broadband or Option 2 for Home Broadband & Home Phone

ISPs: 1999: Freeserve 48K Dial-Up > 2005: Wanadoo 1 Meg BB > 2007: Orange 2 Meg BB > 2008: Orange 8 Meg LLU > 2010: Orange 16 Meg LLU > 2011: Orange 20 Meg WBC > 2014: EE 20 Meg WBC > 2020: EE 40 Meg FTTC > 2022:EE 80 Meg FTTC SoGEA > 2025 EE 150 Meg FTTP

mattius001 · ‎28-12-2022

If i ditch DHCP from the Smart Hub, i might as well just ditch the Smart Hub as it will then effectively be doing nothing for me but adding a layer of obfuscation.

I already don't use it for Wifi, now DNS, now DHCP and its basically just a modem and not a particularly good one.

I think i will just give up and purchase a decent modem/router, at least then when i next switch providers i will have a consistent experience.

bobpullen · ‎28-12-2022

@XRaySpeX wrote:
@bobpullen wrote:
Differs to the Smart Router that assigns custom DNS via DHCP, rather than assigning to the WAN connection: -
It doesn't really! They are just configured on the same page (everything to do with IPv4) but are not otherwise connected.

@XRaySpeX - are you sure about that?

The BT Smarthub 2 (and the Plusnet Hub Two for that matter) have a very similar interface, and for both of those, the custom DNS will be issued as part of the DHCP lease. In fact, when you have things configured this way, you can navigate to the Broadband Status when connected and see that the PPP interface is still assigned the DNS it has obtained from the PPP session. This is depspite all connected DHCP clients using the custom DNS that has been specified.

bobpullen · ‎28-12-2022

@mattius001 wrote:
If i ditch DHCP from the Smart Hub, i might as well just ditch the Smart Hub as it will then effectively be doing nothing for me but adding a layer of obfuscation.
I think i will just give up and purchase a decent modem/router, at least then when i next switch providers i will have a consistent experience.

Fair enough. The solution is there if you need something in the meantime though and it doesn't look too tricky to enable.

If you do give it a go, let me know how you get on.