Disabling NAT on EE Smart Hub

[Drainer]

Hi

I am trying to have my EE Smart Hub act as close to a modem as possible - I know there isn't an actual "modem mode" available, but going by another topic I've seen on here I should be able to get the same effect by disabling my DHCP, WiFi and NAT.

The settings for WiFi and DHCP are easy enough to find, however I can't seem to find a setting anywhere for NAT? Does anyone know where in the settings this is located?

Thanks in advance

[mikeliuk]

Hi @XRaySpeX ,

Is the EE Smart Hub just a straight forward ADSL device?

https://ee.co.uk/help/help-new/phones-and-devices/ee/smart-hub#getting-started/setting-up-your-hub

Edit: I think I misunderstood what Netduma means by "compatible with" ADSL.

[XRaySpeX]

@mikeliuk : No. FYI:

• The EE Smart Hub (black) is a combined ADSL/VDSL modem router..
• The EE Smart Router (white) is a combined ADSL/VDSL/G.Fast modem router.
• The Netduma R1 & R2 are just routers.

Any ISP who supplies routers with their BB will almost invariable supply a modem router.

Yes, many router manufacturers (& others) when they say "Compatible with all Internet connection types (e.g. DSL, ADSL, Fibre etc)" mean they need to be supplied with some source of these, i.e. a modem. You need to read their specs carefully & look out for mention of inclusion of a modem & a list of DSL protocols it supports.

[mikeliuk]

Hi @Drainer ,

If your are confident in the security of the Netduma firewall, I think the most preformant option may be to set a static IP for your Netduma router on the EE Smart Hub private subnet and then put this IP in the DMZ.

This should avoid minimize the double-NAT workload and segregate your low-latency traffic to the Netduma whereas non-latency sensitive connections can go to the EE Smart Hub.

The DMZ setting should ensure that packets are forwarded unmodified minimally modified and you don't bottleneck on rewriting packets on the EE Smart Hub. Port-forwards out of the DMZ are simpler too (you don't need to forward twice). 🤓

Edit: made some corrections as inability to disable NAT on the outer router means it will NAT from the WAN IP to the IP of the second router.

[Drainer]

Thanks to everyone who provided suggestions. DHCP on SmartHub set to a single address, which is what the Netduma is using. DMZ set on that address. Wi-Fi turned off on SmartHub, and everything is working as I want it to. I've even been able to give the Netduma the same SSID and password as my SmartHub, so everything is able to reconnect without me doing anything.

Thanks all.

[XRaySpeX]

Thanks! You're welcome 🙂 ! Glad I could be of assistance & it is now sorted.

Did you try disabling DHCP 1st to lose the NAT? What happened?

[mikeliuk]

DHCP hands out leases and provides configurational information to devices. Whether or not DHCP is enabled does not impact whether NAT is taking place.

You can have NAT and no DHCP, or you can have DHCP for an internal network without using NAT.

Edit: another hint is they are configurations which apply to different interfaces. DHCP listens on the internal LAN interfaces, whereas NAT (or masquerading) is configured on the WAN interface. 🤓

[XRaySpeX]

As I see it if you have no IP addys handed out you have no network addys to translate. It'll be straight in & out/pass thro'.

[mikeliuk]

If you disable DHCP, all devices will keep their IP addresses until their leases expire. DHCP is purely a convenience, you can assign static IP addresses to all devices instead. Whether or not DHCP is configure does not impact whether NAT is configured.

For most people, NAT is not a convenience but a necessity as the service provider may only allocate one IP address which must be "shared" by all devices in a house. This "sharing" is implemented by NAT. Any good introduction to IPv4 will cover network address translation. 🤓

Edit: the fact that your devices have no IP addresses does not cause your router to be in bridge mode. Again, they are distinct interfaces. I can configure anything I want on device interfaces and these configurations cannot impact the WAN interface on the router. If NAT cannot be disabled on the EE Smart Hub, there's no possibility of bridging the WAN interface to the LAN ones anyway.🤓

Edit2: more amusingly, for most consumers, a device interface with no IP address is a pretty severe misconfiguration. Packets can obviously be broadcast across the LAN, but preventing devices from getting IP addresses causes a severe loss of functionality, not gain of functionality. The devices with no IP address will be unable to route traffic out of the router's WAN interface and will be able to communicate with very few other devices.

[XRaySpeX]

@mikeliuk : Then let the leases expire or disconnect them altogether from the EE SH. Then connect them to the subsidiary router which will now issue them with its own DHCP local IPs. Then the NAT of the EE SH will have no work to do even tho' it is present.

Why, when trying to set up an entirely new config of the LAN, remember aspects of the unwanted one?

Devices setting their own fixed IPs are irrelevant to this as they still need to set their own IPs on the same subnet as the router they are connecting to in order to be visible on the LAN.

[mikeliuk]

The service provider will provide an IPv4 address which will only ever sit on the EE Smart Hub WAN. All private addresses will unavoidably need one level of NAT to share the address provided by the service provider.

The second level of NAT will take place at the Netduma WAN, assuming that device is used for routing. Using the second level device for bridging seems to defeat the point of the exercise.

In none of the above is it relevant whether IP addresses are assigned by DHCP, statically, or magically. DHCP is merely a convenience that can be on or off as the network administrator desires.

Devices can be optionally connected to either of the routers. I triple-NAT and have servers with an interface in each of the three subnets.

Apologies if I'm being unclear. My point is these questions don't make any sense: "Did you try disabling DHCP 1st to lose the NAT? What happened?"

Disabling DHCP will not impact whether NAT is configured (which it will be as it cannot be disabled on the EE Smart Hub, apparently).

Edit: as explained in earlier comments, this is also false: "As I see it if you have no IP addys handed out you have no network addys to translate. It'll be straight in & out/pass thro'."

Absence of IP addresses does not make things better but instead kills the possibility of routing to take place.