Can't access a particular website on a particular network

[MarioNintendo]

SOLVED - SEE LAST POST

I've been having issues for the past weeks accessing my university's main website (http://www.umontreal.ca) on my laptop when I'm logged on the school's main network. The website is not down, since all of my friends can access it just fine on their own computer (I can even connect to it on my iPhone). This is a problem, since I need to get there in order to access my courses' informations and whatnot. Strangely enough every other website I go to works just fine.

Using proxys worked for a while, but I need to know if someone out there has the answer on how to fix this. Here we go:

- I use Google chrome (but the error appears on other browsers as well). I get the message "Oops! Chrome could not connect to www.umontreal.ca".
- I tried to change DNS. It didn't seem to work. Right now I use Google's DNS (8.8.8.8 and 8.8.4.4)
- The website works on my laptop when I'm logged on my own router.
- I noticed I can access pages like http://dms.umontreal.ca/, but not http://www.umontreal.ca/ or http://studium.umontreal.ca. I initially thought I was blocked from the whole "umontreal.ca" website, but apparently not for some reason.
- Deleting the cache / resetting my browser didn't seem to help.

Any ideas/tips on what I could do? Thanks in advance, friends.

[Izzy]

Re: Can't access a particular website on a particular network

Does your school require you log into a specific network? It makes me think that since you are connecting from an internal IP and are using a desktop browser with a specific browser user-agent that it could be wanting you to do something such as install a specific anti-virus program or something else.

The browser from your phone and the browser from your computer can both be chrome but every browser has its own user agent. A school network would typically exclude mobile browser and gaming consoles so that they aren't required install things that can't be installed.

I would either contact your schools network help service or try something like this.

https://chrome.google.com/webstore/detail/user-agent-switcher-for-c/djflhoibgkdhkhhcedjiklpkjnoahfmg?hl=en-US

It spoofs your browser user agent into looking like it is coming from something else. Make it look like a mobile browser and maybe it will bypass you from security.

Or maybe you have to do this. http://www.dgtic.umontreal.ca/reseau/vpn.html
Although I don't think you should "have" to connect to a vpn to use school services, but who knows.

[MarioNintendo]

Re: Can't access a particular website on a particular network

Yeah, it does require me to log in at least the first time I try to remember their network on my laptop. What's weird is that it stopped working about 2 weeks ago without warning, after working flawlessly for about a month. I thought it had something to do with my preferences hidden deep in command files, or something... So I guess there's no easy way out of this, huh.

Well thanks for the hint.

edit: lol I can't even access your link

[choof]

Re: Can't access a particular website on a particular network

open up command prompt and type ipconfig /flushdns

then, type nslookup and when you enter interactive mode, type the name of the address that you're having issues with (dms.umontreal.ca)

I personally can connect, and my nslookup looks like this:
> dms.umontreal.ca
Server: cdns2.cox.net
Address: 68.105.28.12

Non-authoritative answer:
Name: dms.umontreal.ca
Address: 132.204.53.103

[MarioNintendo]

Re: Can't access a particular website on a particular network

That looked like an interesting venue, but somehow I still can't access. When I asked the command prompt about www.umontreal.ca, it returned me this result:

> www.umontreal.ca
Server: google-public-dns-a.google.com
Address: 8.8.8.8

Non-authoritative answer:
Name: www.umontreal.ca
Address: 132.204.8.32

This looks similar to yours. Does it mean anything, though?

[choof]

Re: Can't access a particular website on a particular network

nslookup bypasses local and server dns cache, asking the server to look for the location of an address you input. if you didn't get a non-authoritative answer, I would have assumed dns poisoning.

a few questions:
have you tried pinging www.umontreal.ca? and if so, what does it return?
when you say you're using google dns, does that mean you're configured statically? or is that the dns server that your school uses?
lastly, does google give you an error code? such as 404, 503, etc.

[MarioNintendo]

Re: Can't access a particular website on a particular network

nslookup bypasses local and server dns cache, asking the server to look for the location of an address you input. if you didn't get a non-authoritative answer, I would have assumed dns poisoning.

a few questions:
have you tried pinging www.umontreal.ca? and if so, what does it return?
when you say you're using google dns, does that mean you're configured statically? or is that the dns server that your school uses?
lastly, does google give you an error code? such as 404, 503, etc.

Since I'm unfamiliar with pinging, I don't believe I've tried doing it. How does it work?
When I mean I used the Google DNS, I mean I went to the control panel of my computer and manually changed the numbers in the dns, like so:

Google does not give me an error code. The website google.com works just fine. The error I get is really just my browser saying it can't access the website:

[choof]

Re: Can't access a particular website on a particular network

in command prompt, type the following:
ipconfig /flushdns
ping www.umontreal.ca

pinging an address, whether it's an ip address or a website, sends a specific packet that's used to verify connectivity. you send a request and, once the destination receives your packet, it will respond to your request.

it's odd that you have a statically configred dns server lol. who had you configure it that way? I would try selecting "Obtain DNS server address automatically"

aaaaand mfw google chrome

[MarioNintendo]

Re: Can't access a particular website on a particular network

in command prompt, type the following:
ipconfig /flushdns
ping www.umontreal.ca

pinging an address, whether it's an ip address or a website, sends a specific packet that's used to verify connectivity. you send a request and, once the destination receives your packet, it will respond to your request.

it's odd that you have a statically configred dns server lol. who had you configure it that way? I would try selecting "Obtain DNS server address automatically"

aaaaand mfw google chrome

Well Idk, I searched online and seems like statically configuring the DNS to the Google server was the first solution I could find... Turns out this was the cause of the problem! I changed it to "Obtain DNS server address automatically" and it now works like a charm.

Thanks a ton Choof. :)

[choof]

Re: Can't access a particular website on a particular network

no problem!