How to resolve 502 Proxy Error, rejected by HTTP filter (12217)

Dear Experts,

When browsing to various websites users receive the following error:
Error Code: 502 Proxy Error. The request was rejected by the HTTP filter. Contact your ISA Server administrator. (12217)
IP Address: XX.XX.XX.XX
Date: 2/8/2008 4:24:01 PM
Source: web filter

My boss needs to be able to use the search option on, she is able to browse the site, but as soon as she ( and everybody else on the network) hits search, receives the same error. Today I got a number of complaints from users for a number of other websites that they can no longer get to as well as Internet Slowness.

I was looking at this article   but it wont help for a couple of reasons. I temporarily disabled the rule just to check if I can get through, didnt help&

Previous admin created an HTTP filter and I was going through blocked websites, sites that are indicated in the filter are not the ones I try to access when the error is generated. Temporarily disabling this rule didnt let me get through either.

It also appears that Caching is disabled.

Users also complain about internet connectivity slowness.

How can I resolve this issue?  Is the proper way to restart ISA firewall service done from Services and Application on computer management console ?

I will restart ISA service tomorrow, in case it doesnt resolve the issue, what should be my next step?

Im new to ISA and if possible please post detailed instructions.

Thank you in advance.
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technomicAuthor Commented:
ISA Firewall Services was restarted, but it didn't help, I then restarted the server, that didn't help either.
I tried temporarily disabling rules one by one to figure out which rule is blocking and I wasn't able to narrow it down either.
technomicAuthor Commented:
Restarting firewall service or restarting the server didn't help. I was able to resolve the problem by disabling the HTTP filter altogether, but I really don't want to leave the HTTP filter disabled.  I reenabled it until I found another soution. What else can I try?
Keith AlabasterEnterprise ArchitectCommented:
Hey dude (always wanted an excuse to say that) - somehow missed this question.

First things first - lets make sure you are on isa2004 - sp3?
Secondly, the blocking of web sites by name or ip address is not performed by setting an http filter - that is a completely different area. URL & domain sets block traffic to known locations

http 'filters' are used to block particular content-type within a data stream sucgh as video or .exe attachments and the like. Get an http filter wrong and it could certainly cause the type of issue you report.  Easiest way to prove it is to create a new access rule at position 1 allowing http/https traffic outbound from internal to external (no http filter)- all users as a quick (and temporary) test rule. If all goes well then you know the http filter is the culprit. You can then delete the temporary rule and we can play with the filter to get it right.

If we sort this, I get to say 'have a nice day' lol


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technomicAuthor Commented:

HTTP filter is the culprint, I disabled it temporarily over the weekend and sure enough it was the HTTP filter in Add-Ins that was causing the issue. Once the filter was disabled I was able to access the site without issues. I had to reenable it back until I get the filter correctly setup.

Also, no SP2 or the SP3 were installed. Well, I take it back, either previous admin or the guy before him installed SP2 but it crashed the ISA so they reverted it back (removed SP2).

I know that I need to get it to SP3, but with everything else going on, I'm afraid it will be a couple of weeks before I attempt to install SP3. However when I do install SP3, can I install SP3 right away or should SP2 be installed first and then upgraded to SP3?

What info from the filter can I post here that would help define where the problem is ?

I appreciate the help.
Keith AlabasterEnterprise ArchitectCommented:
Http filters are rule specific - ie the filter is applied ONLY to the rule it is associated with. Easiest way to clear it up is make a note of the rule name, the protocols it applies to, the TO and the FROM box and the Users section.
Delete the rule and create it again at the same location and with the settings you copied down. The http filter will be recreated cleanly at default settings.


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technomicAuthor Commented:
I will try that after hours either this week or early next week and will update here.
technomicAuthor Commented:

I apologize for the delay. I haven't tried to recreate the rules yet as I started running to other problems that are potentially associated with the firewall. I will accept your answer as the solution, so I don't keep this question open. Thank you for all of your help.

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