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Sunday, June 12, 2005
« PAG Security Wiki & Ward Cunningham | Main | Solution Task in NAnt - So Much Nicer! »

Now that most folks have enabled Captcha and Referral Blacklists on their weblogs, the spammers have moved on to Trackbacks as a mechanism for spamming. The particular spam domains that I am dealing with are coming from the *.cn tld and I think from one particular domain which I refuse to even mention in order to prevent any type of traffic flow.

I've been dealing with it for a while now and finally got tired enough of it to turn off the Trackback service in DasBlog.  Hopefully this is something that Scott and others working on DasBlog are aware of and have plans to address in a the next rev version of DasBlog.


Looks like that is not an option :-(
After turning off the TrackBack service, if you click on the Trackback link at the bottom of a post, you get the following error:

HTTP status string is not valid.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Web.HttpException: HTTP status string is not valid.

Wonder if the issue is unique to me, or is this a DasBlog problem.... Anyone?

Tags:: Musings
6/12/2005 4:12 PM Eastern Daylight Time  |  Comments [6]  |  Disclaimer  |  Permalink    Tracked by:
"Disabling Trackbacks To Avoid Link Spam" (Tom's corner) [Trackback]
Monday, June 13, 2005 4:06:04 AM (Eastern Daylight Time, UTC-04:00)
I don't get any errors when clicking your trackback link. But if the problem still exists, you could also remove the trackback link from your item template.

BTW: you're absolutely right with this annoying trackback spam. I had to disable the trackback service too a couple of days ago. Aargh!
Wednesday, June 15, 2005 2:26:30 AM (Eastern Daylight Time, UTC-04:00)
I think that is by design. If you disable the service, clients trying to connect will get an invalid page.
Wednesday, June 15, 2005 5:15:32 PM (Eastern Daylight Time, UTC-04:00)
Hmmm... Would you not consider it being handled a bit more gracefully than throwing a server error? Perhaps provide a invalid page message?
Saturday, June 18, 2005 9:38:12 PM (Eastern Daylight Time, UTC-04:00)
Which HTTP Status code does the TrackBack spec say we are supposed to return?

Anil - we JUST added INCREASED support for Trackbacks, an we'll catch all trackback spammers that don't provide you a link. That's caught ALL my trackback spam since.
Sunday, June 19, 2005 12:19:45 AM (Eastern Daylight Time, UTC-04:00)
Scott - Thank You!

As to the error, I hope we are talking about the same thing. What I am talking about is the "Trackback" link that is present on each blog entry a la "Disclaimer | Comments | Trackback".
Click on the Trackback link.. (Try mine). And you will immediately get a "HttpException (0x80004005): HTTP status string is not valid." error. A user should never see this error. I guess I could do a generic catch-all for the Application, but I would rather see DasBlog handled this internally.

You are obviously discussing the actual status code that should be returned by DasBlog to notify someone who is trying to trackback to the blog that their Trackback was denied, for lack of a better word. Right?

According to the Trackback specification @

"In the event of an unsuccessful ping, the server MUST return an HTTP response in the following format:

<? xml version="1.0" encoding="utf-8" ?>
< response >
< error >1</ error >
< message >The error message</ message >
</ response >"
Anil John
Thursday, August 11, 2005 9:17:42 PM (Eastern Daylight Time, UTC-04:00)
I'm getting the same error when I click on any of my 'trackback' links (since turning off the service). I suppose that should also discourage trackback spammers, since they will get an error when trying to trackback?

I'm going to try the newest bits...hopefully the improvements mentioned by Scott Hanselman will help.
Comments are closed.