VeriSign's launch last week of a controversial URL-redirection service has created such a backlash and so many headaches for network managers that workarounds already are surfacing, and mounting pressure might force the company to rethink its strategy.

VeriSign's SiteFinder redirects unknown or mistyped URLs ending in .com or .net to the company's own site-searching engine. The company says the feature is a convenience for Web surfers, but others characterize it as blatantly commercial and an ill-advised disruption of DNS.

"Technically, this change has caused a lot of problems," says DNS inventor Paul Mockapetris, chairman and chief scientist of Nominum, a provider of DNS services to corporations and government agencies. "Obviously, VeriSign is doing this for a commercial interest. But VeriSign is also claiming this will be a useful navigation service for users."

AOL and Microsoft already provide similar redirection services at the browser level, as do smaller domain-name registrars.

"The problem with VeriSign making this change in .com and .net is where VeriSign sits in the DNS hierarchy," Mockapetris says. "It introduces this change into any protocol looking up Internet addresses: FTP, e-mail, any protocol sooner or later looks up an Internet address. . . . Some [corporate] mail servers have been there for 10 years and have never had to deal with this case before."

VeriSign acknowledges SiteFinder has caused unwelcome side effects, but turning off the service "is not under discussion right now," according to Brian O'Shaughnessy, a company spokesman.

"We are looking for ways the service can be modified to accommodate the concerns of anti-spam and e-mail vendors," O'Shaughnessy says. "We're trying to work out the incompatibilities."

VeriSign attempts to help Web surfers find a mistyped site by redirecting unrecognizable URLs to its SiteFinder page that suggests close matches, and the company also sells links from that page to sponsors. But by redirecting all unrecognizable URLs ending in .com and .net to SiteFinder, VeriSign also is wreaking havoc with anti-spam filters that determine if a message is junk mail by attempting to verify the sender's domain name. Spammers often use bogus domain names, leading the anti-spam filters to reject those messages or mark them as spam.