MSNBot will only get to live for less than a month, as starting with October 1st 2010, it will be discontinued in favor of its replacement Bingbot.

Microsoft has announced the change for quite some time, but provided an additional reminder as the death of MSNBot is getting closer and closer.

Come October 2010, Bingbot will take over the role of web crawler for the company’s Bing search/decision engine.

Inevitably, the new bot for Bing will introduce a series of changes that webmasters need to be aware of.

One of them involves a modified user agent name in server logs. The Bingbot will be associated with Mozilla/5.0 (compatible; bingbot/2.0 +http://www.bing.com/bingbot.htm).

And the old HTTP header From field “From: msnbot(at)microsoft.com” will be changed to “From: bingbot(at)microsoft.com.”

“On October 1st, you should see the main Bing web crawler name change implemented. Other MSNBot crawlers will be phased out shortly thereafter,” revealed Rick DeJarnette, from the Bing Webmaster Center.

“The renamed crawler will continue to perform as it did previously. You should not see any differences stemming from this change,” he added.

At the same time, there will be aspects that will not change, even as Bingbot will replace MSNBot. One of them involves the IP addresses leveraged by the software giant’s crawlers. In addition, the crawl rate will also remain the same, Microsoft informed.

“It is critically important that you review your server configurations now for crawler access,” DeJarnette advised.

“Webmaster-managed bot access control methodologies, such as robots.txt files, robots <meta> tag directives, and HTTP headers, may need to be adjusted if you normally block all crawlers except for specific, preferred search crawlers.”

Still, the Bingbot will continue to honor robots.txt directives, even if they refer to the MSNBot.

Still, in the context in which custom directives exist for both MSNBot and BingBot in the robots.txt file, the BingBot directive will be a priority for the crawler.

“If your sites are configured for any special handling based on user agent (such as via the .htaccess file), you'll need to update this for BingBot so we can continue to crawl your sites as before,” DeJarnette stated.

“To keep your content in the Bing index, please ensure that BingBot has the same access to your site as given to MSNBot.”

Webmasters that relied heavily on the Yahoo crawler will also need to get ready for the Bingbot. Essentially, the role of the Yahoo bot has been taken by the Bingbot.

“Given the recent developments with Microsoft and Yahoo! Search Alliance, where Bing is now also powering Yahoo! search results for web, image, and video content, this issue is all the more important,” DeJarnette underlined.