Neil Turner's Blog

Blogging about technology and randomness since 2002

Ping Problems

Recently several people have reported problems with sending trackback pings to this site. It’s evidently not affecting everyone as pings from other blogs are getting through.

One of the following things is happening:

  • Post is being blocked by MT-Blacklist. If the weblog title or excerpt contains spammy words, or the URL looks like spam, MT-Blacklist will intercept the ping and stop it from appearing. If this happens, your weblog will receive a message on the lines of “Ping ‘’ failed: <string>Your ping was denied due to possible inappropriate or questionable content.</string>” and an item will be added to my Blacklist Log, which I check regularly.
  • Post is being blocked by my Apache .htaccess rules. I have some crude but surprisingly effective mod_rewrite rules which seem to block out almost all trackback spam (at least in its current form). Should this happen, your weblog will either show “Ping ‘’ failed: HTTP error: 302 Moved” or something about being unable to ping a static page on this site with a different URL. These all turn up in my Apache access logs so I can diagnose them if you think this is happening.
  • Post is being blocked by mod_security. mod_security is an Apache add-in installed by my host that should filter out bot attacks and spam attempts. Unfortunately it occasionally succumbs to false positives and I have a hunch that it’s been eating some legitimate pings lately. If this happens to you, your weblog software will either say “Ping ‘’ failed: HTTP error: 301 Moved Permanently” or “Ping ‘’ failed: HTTP error: 406 Not Acceptable”. As far as I know I have no way of checking these as they don’t appear in my logs.
  • There’s a routing problem between your server and mine. I don’t think this is likely but it’s a possiblity. Look out for “Ping ‘’ failed: HTTP error: 500 Timeout” . Note that this error will sometimes show even though the ping was received successfully, it’s just that my server is being a little slow to respond. Movable Type users can alleviate this by finding the line “# PingTimeout 20” in their mt.cfg files, deleting the # and changing 20 to something larger, say 30. Posting of entries may take a little longer but you should notice fewer errors.

If you are using Movable Type, you can view trackback errors in the Activity Log from the main screen. Unfortunately WordPress, even in the latest 1.5 version, doesn’t seem to log or even show the results of pings so if a ping doesn’t work you have no way of finding out why.
If those of you who regularly ping me but never see the pings appear would let me know what’s going on then I can see about making remedial action, if possible.


  1. Trackback problem to Neil’s Blog

    I read Neil Turner’s web log and by using the Trackback feature of WordPress, have pinged any of his entries that I have referenced. Unfortunately those pings haven’t been getting through and we’re not 100% sure why. He’s posted a couple of possible is…

  2. Docs.Rage.NET: /apache/filter.html.en

    This was suggested as being relevant by a visitor.