Cannot Connect to RennTech.org forum

[#1]

I regularly struggle to connect to the RennTech website when using a PlusNet connection.

https://www.renntech.org

This happens on my phone or PCs, and happens at my house and my parents house who also have PlusNet.

If I switch off my WiFi on my phone I can connect to the website using mobile broadband so the server is there.

I suspect it's some sort of DNS issue with the site.

It's only this site that gives me issues, everything else for my Internet connection is fine.

Has anyone else experienced this?

Moderator's note by Mike (Mav): Post released from Spam Filter.

[#2]

Moderator's note by Mike (Mav): This thread is now in the appropriate board.

[#3]

No problems accessing it from my PN connection using Google's DNS: 8.8.8.8 and 8.8.4.4

[#4]

The page source data is 6,000+ lines long + there will be many links.

So it will be sluggish.

[#5]

The Plusnet DNS appear to give a choice of timeout or SERVFAIL. Quad9 resolves OK.

C:\Dig>dig www.renntech.org @212.159.13.49

; <<>> DiG 9.11.2 <<>> www.renntech.org @212.159.13.49
;; global options: +cmd
;; connection timed out; no servers could be reached

C:\Dig>dig www.renntech.org @9.9.9.9

; <<>> DiG 9.11.2 <<>> www.renntech.org @9.9.9.9
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 24220
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;www.renntech.org.              IN      A

;; ANSWER SECTION:
www.renntech.org.       14400   IN      A       204.13.239.17

;; Query time: 328 msec
;; SERVER: 9.9.9.9#53(9.9.9.9)
;; WHEN: Sun Apr 08 23:20:51 GMT Summer Time 2018
;; MSG SIZE  rcvd: 61


C:\Dig>dig www.renntech.org @212.159.6.9

; <<>> DiG 9.11.2 <<>> www.renntech.org @212.159.6.9
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 63737
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;www.renntech.org.              IN      A

;; Query time: 2015 msec
;; SERVER: 212.159.6.9#53(212.159.6.9)
;; WHEN: Sun Apr 08 23:21:43 GMT Summer Time 2018
;; MSG SIZE  rcvd: 45

[#6]

Or even:-

dig www.renntech.org @1.1.1.1

; <<>> DiG 9.9.5-9+deb8u15-Debian <<>> www.renntech.org @1.1.1.1
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62222
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1536
;; QUESTION SECTION:
;www.renntech.org. IN A

;; ANSWER SECTION:
www.renntech.org. 14400 IN A 204.13.239.17

;; Query time: 279 msec
;; SERVER: 1.1.1.1#53(1.1.1.1)
;; WHEN: Mon Apr 09 03:08:18 BST 2018
;; MSG SIZE rcvd: 61

[#7]

Thanks, but I'm using the PlusNet DNS
212.159.6.10
212.159.6.9

[#8]

? I'm just trying to use the website and having problems connecting to it on PlusNet.

[#9]

I'm still getting timeouts with dig www.renntech.org @212.159.6.9 but it resolves with Quad9.

@bobpullen any thoughts please?

[#10]

Without looking in too much detail (I'm on a smartphone), I'm guessing there was a duff entry at some point at renntech.org's side and our caches haven't expired it yet.
If you do a dig +trace you'll notice it resolves.

[#11]

Thanks @bobpullen for that insight. Last night using +trace with Plusnet DNS did resolve; the output included the line

couldn't get address for 'ns2.exactservers.com': failure

but ns1.exactservers.com resolved and provided an answer. This morning the same dig +trace www.renntech.org @212.159.6.9 command results in

couldn't get address for 'ns1.exactservers.com': not found
couldn't get address for 'ns2.exactservers.com': failure
dig: couldn't get address for 'ns1.exactservers.com': no more

or from a repeat

couldn't get address for 'ns1.exactservers.com': not found
couldn't get address for 'ns2.exactservers.com': not found
dig: couldn't get address for 'ns1.exactservers.com': no more

Trying dig +trace www.renntech.org @1.1.1.1 also fails with

couldn't get address for 'ns2.exactservers.com': failure
couldn't get address for 'ns1.exactservers.com': failure
dig: couldn't get address for 'ns2.exactservers.com': no more

However dig +trace www.renntech.org @8.8.8.8 returns a failure from ns2 but answer from ns1....

couldn't get address for 'ns2.exactservers.com': failure
;; Received 582 bytes from 199.19.57.1#53(d0.org.afilias-nst.org) in 172 ms

www.renntech.org.       14400   IN      A       204.13.239.17
renntech.org.           14400   IN      NS      ns1.exactservers.com.
renntech.org.           14400   IN      NS      ns2.exactservers.com.
;; Received 145 bytes from 204.13.232.239#53(ns1.exactservers.com) in 157 ms

Repeating the 1.1.1.1 test then gives

couldn't get address for 'ns2.exactservers.com': failure
;; Received 582 bytes from 199.19.54.1#53(b0.org.afilias-nst.org) in 188 ms

www.renntech.org.       14400   IN      A       204.13.239.17
renntech.org.           14400   IN      NS      ns2.exactservers.com.
renntech.org.           14400   IN      NS      ns1.exactservers.com.
;; Received 145 bytes from 204.13.232.239#53(ns1.exactservers.com) in 156 ms

It looks to me that ns2,exactservers.com is permanently in a failed state leaving ns1.exactservers.com to answer all queries that it can cope with. Unfortunately those it can't get no answer. 

One might ask if Plusnet DNS could be more helpfull with its failure message(s)?

[#12]

The problem seems to be with the exactservers.com nameserver configuration. The problem seems to be that to find the IP addresses for ns1.exactservers.com and ns2.exactservers.com, you have to ask ns1.exactservers.com and ns2.exactservers.com, for which you need their IP addresses, so there's a loop and it doesn't work.

[#13]

Thanks for the investigation everyone. Is there a way that this can be fixed?

[#14]

Since it appears the renntech nameservers are unreliable you could try adding the website IP address to your PC/laptop hosts file. That would mean taking responsibility for validating the address.

However that method is unlikely to be available on tablets and phones connected via your home WiFi.

[#15]

Cheers, maybe I can add the IP to my router somehow. I may also try and Tatar this with the RennTech forum if it starts to be a problem at there end. Thanks again