SmartHub DNS Server Faulty

[Axle]

A couple of weeks ago my phone, kindle, tablet and PC all failed to get Internet connectivity through my smart hub (ethernet, 2.4ghz and 5ghz WiFi all affected). My Samsung TV and Alexa still worked and the hub was reporting that the broadband connection was good. After some head scratching I just did a factory reset which sorted the issue. Until today when the same thing happened.  

After a bit of investigation it turns out that DHCP is only giving out the SH's IP as a DNS server with no secondary.  Using static settings on the affected devices using 8.8.4.4 (thank you Google) as a secondary gets the devices back online perfectly.  Before I spend hours on the phone to EE tech support has anyone else experienced anything similar or does it sound like a case of getting a new hub sent out?

Cheers. 

[Mustrum]

@Axle  which router do you have?

Have you looked at the routers DNS settings?

DHCP allocates IP addresses not DNS, but the router should have two DNS addresses and some routers allow you to choose your own option.

[bobpullen]

@Axle - what hub are you using and what firmware version is it running (can find this by accessing the Hub Manager at http://192.168.1.254 and navigating to Advanced > Technical)?

The hub assigning itself as the single DNS resolver shouldn't present problems as the hub should always be available for DNS querying (if it isn't, then you've bigger problems!)

What might be useful if you have access to a Windows machine or similar, is to try running the following from a command line during a period of time when the machine is in the problem state: -

> nslookup bbc.co.uk
(DNS queries the BBC using the default DNS server that has been assigned)

> nslookup bbc.co.uk 192.168.1.254
(DNS queries the BBC explicitly using the hub as the DNS forwarder - should return the same as above)

> nslookup bbc.co.uk 8.8.8.8
(DNS queries the BBC using Google's DNS resolvers)

The output of the above might offer some clues.

Depending on your hub/firmware version, you may be able to reconfigure the hub to automatically assign Google's DNS addresses as part of the DHCP offer. Whilst this may resolve your issue though, it doesn't help figure out why the problem exists in the first place.

[XRaySpeX]

None of EE's current routers, Smart Hub Plus & Pro, allow the setting of the DNS. They default to EE's own DNS.

[bobpullen]

@XRaySpeX - they don't allow reconfiguration of WAN-side DNS but I think the functionality to change the DHCP DNS server assignment exists in places. I've seen it on Smart Hub Plus 2.x firmware.

[XRaySpeX]

@bobpullen : Dunno what you mean by "DHCP DNS". There are no domains locally.

[bobpullen]

@XRaySpeX - the DNS servers assigned to a client as part of the DHCP lease. This is configured under Advanced > Network > IP configuration in the Hub Manager i.e. the same page where you would toggle DHCP on/off & configure ranges etc.

Local domain name resolution is a thing but that's irrelevant here; we're just talking about the DNS server address(es) that are assigned to a client when it obtains its network configuration from the hub using DHCP. By default the DNS server assigned will be the hub's IP address, however functionality exists to change this.

[XRaySpeX]

@bobpullen : Didn't understand much of that! On Advanced > Network > IP Configuration page of SH+ there is just a Lease Time but nowt to do with DNS.

[bobpullen]

@XRaySpeX - I'll post a screenie when I next get the chance, unless somebody else beats me to it in the meantime.

[bobpullen]

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@bobpullen wrote:

@XRaySpeX - they don't allow reconfiguration of WAN-side DNS but I think the functionality to change the DHCP DNS server assignment exists in places. I've seen it on Smart Hub Plus 2.x firmware.

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@XRaySpeX - this is what I mean: -