Issues accessing Prezi

[Hawkeyez]

Had a helpdesk logged by a teacher, saying she is unable to access prezi.com. On request for further information, I was told, she could get to the site, login fine, but was unable to create/edit presentations. An error stating;

 

There was a problem loading your prezi.

 

Please check your internet connection or firewall, and allow traffic to prezi.com. Also, please make sure you have the latest version of Flash.

 

After checking flash versions etc, and testing on other machines, I determined, that either going via RM Smartcache, or direct to of LEA Proxy, had the same result.

 

Next step was to look at our ISA box. After running a monitor on my attempts to access the site, I got the following

 

 

Failed Connection Attempt CLW-SR-ISA 15/06/2012 10:35:56

Log type: Web Proxy (Forward)

Status: 995 The I/O operation has been aborted because of either a thread exit or an application request.

Rule: SysAdmin PC External Access

Source: Internal (192.168.2.68)

Destination: External (46.18.180.65:80)

Request: log.prezi.com:443

Filter information: Req ID: 0fd5205e; Compression: client=No, server=No, compress rate=0% decompress rate=0%

Protocol: SSL-tunnel

User: anonymous

Additional information

Client agent: Mozilla/5.0 (Windows NT 5.1; rv:12.0) Gecko/20100101 Firefox/12.0

Object source: Upstream (Object was returned from an upstream proxy cache.)

Cache info: 0x0

Processing time: 0 ms

MIME type:

Anyone had this before? or know what I could do to resolve?

[Davit2005]

Just noticed in your post:

 

Destination: External (46.18.180.65:80)

Request: log.prezi.com:443

 

Have you identified the 46.18.180.65 ip address? I don't need to know what it is but could it be your upstream proxy blocking as the destination is port 80 (http)and the site is requesting a 443 (https)

 

To me it looks like the upstream proxy is blocking the 443 request.

 

Have a word with the LEA providing the proxy I guess would be an idea.

[Hawkeyez]

Our Macs using Smoothwall, that bypass our ISA is fine, just any traffic going though the ISA box is having issues.

 

46.18.180.65 is the IP of the LEA's proxy.

[36Degrees]

Did you get an answer to this? We are having the same issue and although I will contact the LEA any additional information would be gratefully received.

[glennda]

You will find that Prezi launches Java script from one of google's servers. that is the cause of the issue with the page not being loaded as this tends to be blocked.

[36Degrees]

That confuses me even more as we have supposedly had the LEA's firewall rules amended to allow access to all google servers, due to issues we had with Google Docs! I don't suppose you know which Google server?

[glennda]

I have a feeling it something like code.google or similar - if you open up the page and view the source you can see the Js its trying to pull i think.

[Hawkeyez]

Still the same here, added all sorts of different domains to the allow lists on the filtering (as below), and still get the same issue.

 

Domains..

 

.prezi.com

 

.prezi.com:443

 

.cloudfront.net

 

.cloudfront.net:443

 

s3.amazonaws.com

[glennda]

If you load the page and then view the source you should be able to see the pages its loading. Or try firebug.

 

It used to load the JS files from google which is most likely blocked.

[Duke5A]

Inspect your proxy logs for all outgoing connections from a client with Prezi loaded in the browser the moment the page refreshes. I've had sites pull content from servers by using an IP address instead of a domain name and our upstream proxy is setup to block browsing by IP. Placing that single IP on a white list usually fixes that.

 

Another issue I've seen is pretty much the same scenario, but the IP address keeps changing as the external content was hosted on a cloud service.

 

I hope this helps...