Author Topic: Zentyal's proxy in the real world  (Read 19214 times)

Sam Graf

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Re: Zentyal's proxy in the real world
« Reply #30 on: May 21, 2012, 05:30:34 pm »
What am I missing? I'm on speaker-phone which isn't the best situation anyway, but all I get is mumble mumble A records mumble mumble. And then, but I can do the 301, it's just not how I would do it.

If I had to address this, I would:
- determine whenever users still have or can access the former web site
- understand whenever I can or not update web pages on the former web server
- based on above, change DNS to point, if this is the goal, to the new server. This has to be done carefully because there are some pitfalls as web site reached by user is not the one initially requested. BTW, is there any use of HTTPS here?
No HTTPS. The former site will pass forever into obscurity, the domain name will expire. So the goal isn't to have DNS point to the new server as such, but for the old domain to redirect to the new. To me these are two different goals (I don't care about the DNS server, only the permanent change of address and conveying that to user agents), but I'm not confident I have all the facts to really know that. :-[

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #31 on: May 21, 2012, 05:37:39 pm »
DNS and HTTP 301 are complementary, to mee.

Without DNS, users will always access the old site and be redirected until server disappears.
With DNS change + HTTP 301 permanent redirect, user without any cached entry (think about DNS cache here) will ask DNs and point directly to the new server while others will access the old server and then be redirected to the new one.
You may also have some hard-coded link (meaning IP address) somewhere, reason why HTTP 301 is mandatory.

Sam Graf

  • Guest
Re: Zentyal's proxy in the real world
« Reply #32 on: May 21, 2012, 05:45:42 pm »
Had he explained that to me, that yes, we want the 301, but have I considered the fact that for a few months people who visit the old site will always get the redirect, and that we could avoid that, I might have been able to follow his point. Instead, he starts with the idea that I have to do the redirect at my end. And I am immediately lost. I'm not sure it really makes a lot of practical difference in my case, but it does seem to me (now) that the complementary approach is the more elegant one.

Thank you for taking the time to patiently take me from the bit I do know to the bit I didn't know. You are a good teacher. :)

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #33 on: May 21, 2012, 05:47:17 pm »
 :P

Sam Graf

  • Guest
Re: Zentyal's proxy in the real world
« Reply #34 on: May 21, 2012, 05:58:32 pm »
Seriously.

I'm still not sure how that all works if DNS changes (I'm assuming the domain eventually shows up in cPanel?), but at least I could have asked a few more useful questions along that line.

By the way, a few months back I bought O'Reilly's TCP/IP Network Administration to try to remedy some of my ignorance. I even pulled it off the shelf to try to figure out what the guy was trying to tell me. So I got a little smarter about the reference to A records (I had a vague idea of where he was headed, but I was thinking in terms of DNS transfer, not DNS redirection), but I still missed the connection. Maybe this lack of common sense is common to part-time small business administrators, who have too much variety on their task list? :-[

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #35 on: May 21, 2012, 06:07:17 pm »
Well, we are not discussing about "DNS redirect" here but to point www.olddomain.com to www.newdomain.com

This is a CNAME or A record that you have to change.

Pay attention that you will need server at the endpoint answering to such "www.olddomain.com" request  ;)
What this bring is that even if the old server is not up, requests from clients will reach server YOU manage.
I made the assumption that DNS is the one from the registar but I might be wrong.
Another point to be taken in account is whenever target (old) server is used by other virtual servers. This may limit your flexibility to work at DNS level with A record.

Sam Graf

  • Guest
Re: Zentyal's proxy in the real world
« Reply #36 on: May 21, 2012, 06:24:50 pm »
DNS redirection wasn't the right term. Sorry. :-[

My thought was to let the server hosting olddomain.com to earn its keep by doing the redirect. As I mentioned, the contract expires in the fall. I have no other use for that server or account. It is a complete hosted solution, so I have no direct control over any aspect of the site, including content updates and corrections. And in my case, that matters  because the old site needs to be almost completely rewritten from the ground up, in terms of content. The existing site is full of errors. It made (and makes) sense to me just to move everything permanently to the domain of our choosing and situate things so we can fix the content easily, and to let their server pay for itself by doing the redirect.

I'm assuming that the old server is a shared host. But it was their admin that said the change should be (I think), 1) change the A record, and 2) do the redirect on our host's server. If there are complications to that, he didn't make that clear (to me).

Maybe at the end of the day it was just simpler the way I did it. :'(

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #37 on: May 21, 2012, 06:29:50 pm »
[Tentatively teaching mode on  :P]

Main difference between HTTP 301 and DNS CNAME or A record pointing www.oldsdomain.com to www.newdomain.com
with A or CNAME record, browser asking for www.olddomain.com will either ask proxy (in case of explicit proxy) or resolve www.olddomain.com to get an IP address then will contact this IP and expect to reach www.olddoamin.com. This means that web server at this IP must answer to www.olddomain.com

In case of HTTP 301, client (or proxy) will also resolve www.olddomain.com, reach this IP and get HTTP 301 return code asking browser (or proxy) to redirect to www.newdomain.com

So what's the real difference?

HTTP 301 only looks simpler, no need to deploy temporarily web server for www.olddomain.com but it doesn't solve some aspects because HTTP 301 works at page level; you could redirect only few pages, not all. But this also means that in case someone accesses short cut to something else than main page where you put your HTTP 301, redirect will not occur.
On the other hand, DNS change will apply at server level.

[teaching - and joking - modes off]

Sam Graf

  • Guest
Re: Zentyal's proxy in the real world
« Reply #38 on: May 21, 2012, 06:39:39 pm »
No, I am learning. Wrong topic altogether (I will fix that eventually), but I am learning.

The cPanel "point and click" implementation is global in the sense that you redirect the entire domain to a new domain in one action, not select pages. Maybe via htaccess? Or maybe cPanel will change the DNS record too?

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #39 on: May 21, 2012, 06:44:10 pm »
I don't know cPanel  :-[
What I know is that if you replace one page with another one sending back HTTP 301, that you will have redirect when this page is reached.
Then perhaps cPanel does something magic here, replacing all pages  ;)
changes at DNS using cPanel... hum, I have strong doubts, at least if you don't own DNS because managed by your ISP or registrar.

Sam Graf

  • Guest
Re: Zentyal's proxy in the real world
« Reply #40 on: May 21, 2012, 06:55:08 pm »
Well, June 1 we are redirecting a site through cPanel where both domains are on the same DNS server and the one cPanel has access to (cPanel provides "Simple DNS Zone Editor," where "This feature allows you to create and edit A and CNAME records"; I guessing that it can do automatically, if that's part of the deal, what it allows me to do manually).

I'll see if I can sort out what cPanel has done on June 1 and report back (in teacher mode).

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #41 on: May 21, 2012, 07:07:30 pm »
just to be 100% exhaustive, if possible:
if you do DNS only, then you will have a (short) period of time during which some users will still access old serverafter June the 1st with no redirect to the new one because of DNS propagation delay and also cache effects.
If this matters and if you do need to avoid this, I would suggest you change TTL, at DNS level, few days in advance so that you speed up propagation.

christian

  • Guest
Re: Zentyal's proxy in the real world
« Reply #42 on: May 22, 2012, 05:53:53 pm »
Another - different - look at the real world  :P

To solve this request, explicit proxy is even not enough  :o but WPAD does the trick  ;D

If it could convince Zentyal team to implement WPAD "service" out-of-the-box..  ::)

Wingthe

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Re: Zentyal's proxy in the real world
« Reply #43 on: October 16, 2012, 12:18:06 pm »
I opt for Zentyal's HTTP Proxy implementation since it filters content, disallowing banned sites or content types.
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