January 25, 2004
What is Trackback?
Updated April 30, 2005
TrackBack is a feature of Movable Type (and Typepad) that allows you to let other sites know that you have linked to them, and lets you know when other sites have linked to you.
If enabled, the TrackBack feature will place a direct link on your Movable Type entry to entries from other sites that are linking to your entry. Conversely, if you place a link on your weblog entry that links to another site's entry, a link to your site will show up on the other site's entry.
Here an example of TrackBack in action. In this entry you can see that 7 other weblogs are referencing this entry.
Clicking on the TrackBack link will show the list of other sites or weblogs that are referencing this entry.
Why is TrackBack useful?
1. It's kind of cool to see that other people are thinking well enough of what you have written on your weblog to actually link to it.
2. It allows you to comment on someone else's entry without actually having to make a comment in their comment field. If you think well enough of what they wrote to write about it on your own weblog, you don't have to leave a comment on their site in order to let them know you are writing about them.
Why is TrackBack problematic?
1. If you allow TrackBack on your weblog, you are letting anyone place a link to their site on to your blog. This capability has been abused by spammers (see ahead to the TrackBack Spam section). As of this writing, there is no built-in way to moderate TrackBacks. However, you can install the MT-Moderate plugin which will allow you to approve TrackBacks before they post.
2. If you allow TrackBack links, you will need to do more site maintenance to remove TrackBack links that are no longer valid. Otherwise, your site will be filled with links to 404 error pages, which can reduce your ranking with the search engines.
Alternatives to TrackBack
There are several alternative ways to track if people are linking to your weblog, most notably Technorati and del.icio.us.
How to enable TrackBack
TrackBack only works if both sites that are being referenced (either you are referencing another site or another site is referencing you) have TrackBack enabled. To enable TrackBack from your end, go to the weblog config window for your weblog. Click to the preferences window.
Scroll down to the Publicity / Remote Interfaces / TrackBack section.
Selecting Allow Pings on by default will let other sites reference your weblog entries through TrackBack. Selecting this will set the default for all of your entries. In addition, you can turn Allow Pings on or off on an individual basis for each of your entries on the entry edit window.
Selecting Turn on TrackBack auto-discovery will cause your Movable Type system to look at any external links you may have in your blog entry, see if those links go to pages on sites that are TrackBack enabled, and if they are, send a "ping" (a computer's way of saying hello) to those sites. When you save your weblog entry for the first time, the sites to which you are linking will be pinged, and you will see a message screen that looks similar to this:
You can also specify certain URLs to ping on an individual entry case-by-case basis. Near the bottom of the edit entry screen for each entry is a URLs to Ping window. If there is a specific entry of someone else's weblog that you have written about in your entry, you might want to ping that site if you don't already have TrackBack auto-discovery turned on. You can find a specific TrackBack URL for someone else's weblog entry by scrolling to the bottom of the entry. If they have TrackBack enabled, you'll find the TrackBack URL that you can copy and paste into your URLs to Ping window. If you cannot find a reference to TrackBack on someone's entry, they probably do not have TrackBack enabled, and therefore you would not be able to ping them using TrackBack.
Similar to comment spam, spammers have found a way to abuse Movable Type's TrackBack feature. They ping your weblog entry's trackback, even though they have nothing to do with your entry, they just want a link back to their website showing up on yours. There are several measures you can take to counteract Trackback spam. See the LMT tutorial Trackback Spam for details.
Odd TrackBack Auto-discovery Behavior
Note that TrackBack auto-discovery only looks for links in the MT Entry section, not the extended entry section. Following the code change directions in this thread on the MT Support forum will make auto-discovery work with extended entries.
TrackBack Timeout Error Messages
When sending pings, Movable Type sets a timeout on the amount of time it takes to send the ping, so that the system doesn't appear to freeze up. The default timeout time is 15 seconds. If the ping takes longer than that, you'll get a timeout error message.
You can adjust the timeout period by going into the mt.cfg file, un-commenting (removing the # at the beginning of the line) the PingTimeout line and changing the number in that line to a larger number of seconds.
# PingTimeout 15
Here are directions to do this in the MT Manual.
TrackBack is dead. Are Comments dead too? - thoughtful article on the current usefulness of TrackBack.
Inline Trackbacks - a Learning Movable Type tutorial on how to have trackbacks appear on the entry page like comments.
Movable Type's A Beginner's Guide to TrackBack
Mahajabah.com What is Trackback
MT Wiki�s TrackBack explanation
Trackback Spam - LMT tutorial
Has this tutorial been helpful? Please consider linking to Learning Movable Type at http://learningmovabletype.com/ . Thanks!