Telecom Broadband caching and DNS question

Forums › Spark New Zealand › Telecom Broadband caching and DNS question

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Topic # 66599 20-Aug-2010 17:53

Hello,

Does Telecom do some kind of transparent caching?

I've recently had a new broadband connection setup with Telecom and I'm unable to access any websites where I've setup my own private DNS entries.

I can ping the sites fine but when accessing them in a browser, I get the following:

Network Error (dns_unresolved_hostname)

Your requested host "test-server" could not be resolved by DNS.

For assistance, contact your network support team.

This only started happening after I switched to Telecom. Thoughts?

freitasm

BDFL - Memuneh
61304 posts

Uber Geek
+1 received by user: 12043

Administrator

Trusted

Geekzone

Lifetime subscriber

Reply # 370409 20-Aug-2010 17:57

Telecom has been deploying some cache servers, as per previous discussions here on Geekzone.

Let's see if someone posts here about this problem.

Backblaze cloud backup (personal and business) | Geekzone broadband switch | Amazon (Geekzone aff) | MightyApe (Geekzone aff) |

My technology disclosure | Business Transformation | Enterprise Content Management | Customer Relationship Management

ptinson

677 posts

Ultimate Geek
+1 received by user: 27

Trusted

Reply # 370493 20-Aug-2010 21:05

Hi Caldazar,

Yes Telecom uses transparent proxy caches.
By private DNS entries I suspect you mean either entries in your hosts file or on an internal DNS server?

Due to the nature of the caches and how they operate not using the Telecom DNS servers can and does have unpredictable results for browsing international sites.

We can bypass sites that cause issues or don't respond, please just PM me and i can have it done. Its usually an overnight process though.

Regards

Paul

meat popsicle

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Reply # 370530 20-Aug-2010 23:27

Yes they are entries in my hosts file. I have many testing platforms and they are all responding in the same way.

I don't want to bypass a particular site. Can I bypass all sites?

I need to work and can't have things "cached" like this.

ptinson

677 posts

Ultimate Geek
+1 received by user: 27

Trusted

Reply # 370561 21-Aug-2010 07:30

Hi Caldazar,

If you are a static IP customer then yes you can be placed in a bypass list.
If you are not then specific sites/IP addresses need to be bypassed sorry.

Please let me know via PM if you have a static IP and want to be bypassed

Regards

Paul

meat popsicle

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Reply # 370564 21-Aug-2010 08:03

Hi Paul,

Thanks for your help. I have requested a static IP yesterday. Is there any way I can call someone to hurry this up? I have a deadline looming and this is putting me out of action.

It seems like my only other option is to setup a squid proxy (on an external network) but really I should not need to go to that effort, just to use my internet connection.

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Reply # 370580 21-Aug-2010 09:24

Ok, I have managed a work around, temporarily until I can get the static IP confirmed and added to the bypass list.

I don't think the transparent cache is very transparent.

ptinson

677 posts

Ultimate Geek
+1 received by user: 27

Trusted

Reply # 370583 21-Aug-2010 09:31

Hi Caldazar,

Glad you have worked around it.
It is transparent in so far as the clients public IP is used in requests to web servers.
We do insert a via header so we can track caches when there are issues though.

I was going to suggest that instead of using a squid proxy what i normally do is use putty or mobaxterm to setup a socks proxy to either the host or a point in the same network as the host.
This of course assumes you are running an SSH daemon though or a socks proxy...

I do it that way so that the hostname i am browsing to doesnt need to change.

Please let me know when you have your static and i can arrange to have it placed in bypass.

Regards

Paul

meat popsicle

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Reply # 370593 21-Aug-2010 09:51

Ah ok, so that means a site visit to a cached website still registers as a "hit" on the remote server right? It's just that the content is delivered by your cache?

Yep, I do use SSH access, so socks proxy it is for now.

ptinson

677 posts

Ultimate Geek
+1 received by user: 27

Trusted

Reply # 370601 21-Aug-2010 10:18

That really depends on how your site is setup.
If you have CacheControl headers to make sure a proxy cache does revalidation then yes that would be true.
All hits to a web server that pass through the cache should have the clients IP and not a cache IP if it has a cache one we have an issue i wan to know about.

We honor all CacheControl, expires and Pragma headers and we try to honor the Meta tags as well.
Pragma is of course a clientside header so if we see it we do a HEAD request to the site and if it says the content has changed we will do a full load, if it hasnt then we do a cache fill of that request.

If there is no revalidation set then the hits to that Origin Content Server will drop as content is published from the cache.

Hope this makes sense.

Paul

meat popsicle

caldazar

428 posts

Ultimate Geek
+1 received by user: 4

Reply # 370615 21-Aug-2010 11:16

Cool, thanks for the information.

If I notice any other problems, I'll let you know.

One other question. If your cache is returning the error message in my initial post, why don't you brand it with Telecom or at least with the name of your cache server? It might be a little easier for operators to diagnose.

ptinson

677 posts

Ultimate Geek
+1 received by user: 27

Trusted

Reply # 370683 21-Aug-2010 14:39

No problem.

The error page customisation is on the plans its just not the highest of priorities at the moment.
I agree though, for errors generated at the cache the error page should be more helpful, i will raise it with the project on Monday.

Regards

Paul

meat popsicle

lissie

434 posts

Ultimate Geek
+1 received by user: 22

Reply # 371489 23-Aug-2010 13:43

So just to confirm that Telecom is now like Telstra Clear - you can't use a local hosts file in order to develop a site on alternative hosting prior to it going "live" without having a static IP address with Telecom broadband AND notifying Telecom each and every domain you want to honour your hosts file?

How on earth to website developers work in this county? (For what is worth - local hosts work just fine in Australia)

I help authors publish their books - DIYPublishing.co.nz

gmball

347 posts

Ultimate Geek
+1 received by user: 58

Reply # 371498 23-Aug-2010 14:19

Dire speeds here on Telecom PRO, so sick of the lack of action that I have today signed with another provider and happy to give them my $200+ per month phone and broadband account.

asianbro

47 posts

Geek

Reply # 424742 6-Jan-2011 18:34

I'm having very similar issue: http://www.geekzone.co.nz/forums.asp?forumid=39&topicid=74750

And Telecom, can you please make it a priority to brand the error 'Telecom'.

Because the error isn't branded 'Telecom' I actually spent almost my whole day just to figure out what's happening. I work from home as a freelancer and spend hundreds every month for my Telecom connections, and this kind of time waster costing me even more!

Lastly, I have to calm myself down after my call to Telecom 'technical' support (read my thread for more details)

Thank God for this thread