Cannot access external staff URL in school - DNS issue?

[TMBS]

Hi everyone

 

We have a staff domain in school that is hosted on an external server. In school we cannot access the page but at home I can, so I know the issue is a school network one. We can access all other URLs.

 

We run Server 2012 and I know that we have had issues in the past with this and my old technician has set up a Forward Lookup Zone in DNS Manager to rectify this - though I'm not sure why if someone would like to explain this?

 

Any idea what this could be? I've restarted the DNS service and rebooted the server but to no avail - HELP!

 

Thanks

Tracey

[Nixon77]

Has anything changed on the external server?

[TMBS]

No, nothing that I'm aware, or have been informed of. I can access it from home just not school.

 

Thanks!

[kmount]

Hi,

 

Ping it from home note down the IP that it returns.

 

Ping it from school, compare if the IP is the same or not.

 

(it may be that the external provider changed the IP of the site you're trying to access and because your colleague added a forward zone for it it won't necessarily know of the update)

[TMBS]

Yes have pinged from both and both the same.

 

Thanks!

[kmount]

OK that rules out DNS shenanigans.

 

What actually happens when you try internally, what do you see?

[TMBS]

We get the following error:

 

Check access to the specific site - the HTTP error code is 504: Gateway Timeout

 

Thanks

[Steve21]

When you say "Staff Domain" what is the link? As in is it the same as you domain internally? So it might be bypassing proxy?

 

What's the IP it pings to, (internally and externally as someone mentioned), if they're the same can you access the website via the IP address?

 

Steve

 

Steve

[TMBS]

Our staff domain is staff.tmbs.org.uk and the IP is 109.123.76.128. This is hosted on an external server and not the same as our internal domain, I can't access either in school.

 

I've spoken to RM who have checked the server and they said it's a proxy/firewall issue. I've spoken to Smoothwall who have said it's a firewall issue and that Smoothwall can't connect to port 80. I've spoken to KCOM who have said I need to fill in their ridiculous Firewall spreadsheet to make any changes! But why would this stop working? Up until Friday it worked just fine.

 

The big problem is this is all gobbledegook to me, so I'm not sure if I'm being fobbed off. Anyone know of a good networking course? Or website to get me up to speed with the basics?

[Steve21]

So if it's a port 80 problem does this work? https://staff.tmbs.org.uk (ignore the erorr if it loads) but the principal

 

Steve

[TMBS]

No afraid not

[DGardiner]

it wouldnt happen to be set to bypas the proxy or anything?

 

by default port 80/443 are closed here to force everything through the proxy server, so it couldnt directly connect without going via the proxy.