Local recursive DNS and DHCP issues

[OwenMcShane]

Hi,

I posted this earlier but it was removed. Here it is again, this time without reference to another broadband provider by name, in case that was the reason it was deleted:

Hi,

My Vodafone broadband went live yesterday.

I run a mail server for my own domain name, the hostname of which is managed using a dynamic dns service, which is receiving mail fine after the switch over, and setting up the relevant port forwarding on the router.

However, I also run a caching name server for my local network, which I have also set to be authoritative for my domain. This is so my portable devices receive the public facing IP of the router when I am away from my network, but when I am at home, they used to receive the private ip of the mail server when it was looked up. This obviously avoids any need to constantly be swapping mail server details from hostnames to ip addresses and vice versa depending on location.

In order for this to work, I need to be able to tell the Vodafone router to issue my DNS server via DHCP to the clients on my network. There does not appear to be an option to do this. There is an option to change DNS servers, but that appears to be just the ones the router itself uses for recursion.

An equally big problem is that since switching to vodafone my name server is no longer able to do recursive lookups:

$ host mail.google.com 127.0.0.1
Using domain server:
Name: 127.0.0.1
Address: 127.0.0.1#53
Aliases:

Host mail.google.com not found: 2(SERVFAIL)

Looking up hosts in my domain is fine:

$ host mail.XXX.org.uk 127.0.0.1
Using domain server:
Name: 127.0.0.1
Address: 127.0.0.1#53
Aliases:

mail.XXX.org.uk has address 192.168.1.25

(Incidentally, using the Vodafone router's DNS produces the public view, as expected:

$ host mail.XXX.org.uk 192.168.1.1
Using domain server:
Name: 192.168.1.1
Address: 192.168.1.1#53
Aliases:

mail.XXX.org.uk is an alias for XXXuk.ddns.net.
XXXuk.ddns.net has address 90.255.100.xxx

It appears as though recursion from my name server through the root servers is being blocked either by Vodafone somewhere upstream, or the router itself:

A dig at the router produces the expected root name server results:

$ dig @192.168.1.1

; <<>> DiG 9.8.1-P1 <<>> @192.168.1.1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38632
;; flags: qr rd ra; QUERY: 1, ANSWER: 13, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;. IN NS

;; ANSWER SECTION:
. 28354 IN NS h.root-servers.net.
. 28354 IN NS m.root-servers.net.
. 28354 IN NS i.root-servers.net.
. 28354 IN NS e.root-servers.net.
. 28354 IN NS d.root-servers.net.
. 28354 IN NS k.root-servers.net.
. 28354 IN NS a.root-servers.net.
. 28354 IN NS f.root-servers.net.
. 28354 IN NS j.root-servers.net.
. 28354 IN NS c.root-servers.net.
. 28354 IN NS l.root-servers.net.
. 28354 IN NS g.root-servers.net.
. 28354 IN NS b.root-servers.net.

;; Query time: 32 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Thu Apr 13 10:45:29 2017
;; MSG SIZE rcvd: 228

Whereas, my server fails:

$ dig @127.0.0.1

; <<>> DiG 9.8.1-P1 <<>> @127.0.0.1
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 14951
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;. IN NS

;; Query time: 32 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Thu Apr 13 10:45:39 2017
;; MSG SIZE rcvd: 17

So basically I have two problems:

1) My name server can not perform recursive lookups due to some configuration either at Vodafone, or on the router.

2) I am unable to issue my own name server to clients via DHCP on the router. With my old router this was very simple. I could set up my own DHCP server and disable DHCP on the router, but I am still left with problem #1

Can anyone please shed some light on these two issues?

If problem #1 is some hard coded configuration on the router, then I would be more than happy to go back to using my old router for connection, as it is a lot more configurable.

I would obviously require login credentials for this, which I understand is not Vodafone's policy to provide. However, unless this can be resolved by some means, I am missing basic functionality that I require.

My transfer to Vodafone went smoothly, and apart from the two items listed above, I have no other current problems. However, clearly I am still well within my cooling off period, so I would appreciate some input from somebody technical at Vodafone regarding this before I consider my options.

Thanks.

[OwenMcShane]

I posted a query to this forum with the subject "Local recursive DNS and DHCP issues" (or similar) a short while ago.

This post has been removed.

Please may I ask why? Did I inadvertantly break some sort of code of conduct of the forum?

If I repost the query, will it just be removed again?

Regards,

[redpages]

That's strange. From using the forum since 2008 the team will typically notify posters if something has been removed + explain why. The forum has recently undergone a platform upgrade (new look and feel) so maybe there was a glitch in the back end which made it vanish? Your repost is working fine for me now. 

[OwenMcShane]

Yep, I found it bizarre. It was definitely there, because I re-read it and spotted a typo, which I edited.

I took a screen shot of the repost, just to prove I wasn't going mad :smileywink:

[Colleen]

@OwenMcShane Our Broadband Live Chat team will be happy to look into this for you and will be able to provide detailed information regarding your query

[OwenMcShane]

After speaking to three separate advisors via the Live Chat I have received no help or insight.

The conversation ended thus:

--------------------------------

Daniel at 10:47, Apr 17:
Unfortunately there isn't anyone we can raise this too. I really wish we could help further with this but it's just unfortunate that our routers are designed for general standard use so there isn't anyone who would be able to provide further assistance with this unfortunately

Owen McShane at 10:49, Apr 17:
So you are saying there really is no one who can be contacted regarding this?
Daniel at 10:49, Apr 17:
Unfortunately not at the moment
Owen McShane at 10:50, Apr 17:
Will there be at some other time?
Daniel at 10:51, Apr 17:
I don't want to guarantee anything. But Vodafone Broadband is relatively new and they do keep progressing it so it could be something they look at in the future
Owen McShane at 10:52, Apr 17:
OK Daniel. Thanks for your time.

--------------------------------

I find it very hard to believe that there is nobody this can be escalated to. I have over fifteen years experience of UNIX/Linux systems administration with two internet service providers, and the University of Manchester. If a matter such as this arose that could not be dealt with it would have been raised to either myself or one of my colleagues.

Can I please be provided with some contact info for your sysadmin and/or network team(s) in order to get to the bottom of these issues?

Thanks.

[Becca_P]

@OwenMcShane

The advice you've received from our Broadband Live Chat team is correct.

As mentioned, our broadband is relatively new and there's currently no escalation process for the information you're requesting.

We're sorry for any inconvenience for this. 

[OwenMcShane]

---

@Becca_P wrote:

The advice you've received from our Broadband Live Chat team is correct.

As mentioned, our broadband is relatively new and there's currently no escalation process for the information you're requesting.

We're sorry for any inconvenience for this. 

---

A most unsatisfactory reponse. 

Who installed, configured, and presumably still maintains, your network and systems architecture? Or was it simply handed over as is with a note saying "Good luck"?

Sorry, I'm being facetious here, but it is surprising that there appears to be no way for you to communicate with the people who run your setup.

As far as my issues are concerned, I have done the following:

1) Configured my name server to forward any requests for which it is not authoritative, i.e. anything that isn't in my domain name, on to the router for resolution.

2) Set up my own DHCP server, issuing ip addresses on my network to the various clients, along with giving my DNS server.

3) Disabled DHCP on the router.

Therefore, when a client asks for the name of a host in my domain (my mail server, etc.) from within my network, my name server gives the 192.168.1.x ip address. Also requests for external hosts are met due to the forwarding.

Requests from outside of my network are given the public IP of the router, which then uses port forwarding to speak to the correct server.

Owen

[JamieSW]

Ah, that might explain a DNS issue that's been frustrating me this weekend.  I have a raspi set up as DHCP server so I can assign fixed IPs, hostnames and other options to devices on my LAN, and I have told the router to use OpenDNS.  I also wanted to override the "default DNS" on the router for some devices but regardless of what DNS I send to devices via DHCP ("options-dns-servers") the router seems to redirect any DNS queries to the default DNS.  I know the devices have received the override DNS server but queries are still sent to the default DNS (using dig +trace). 

So it does seem that Vodafone have decided they know better and won't let us send our own DNS queries.

It used to work fine with a previous provider.

[ChazzD]

@OwenMcShane @JamieSW @delta-mike

Our dedicated Broadband team are on hand to help with any broadband related queries you have. They can be contacted via Live Chat or on 08080 044 848.

We do have a Technical team that they would then escalate to if needed. Depending on the nature of the query, if the Broadband team already provided all the available information they have, then it's not something they would need to escalate.

We do offer a 30 day cool off period with all of our products and services. If you're unhappy with any part of it, you can cancel your contract during this time.