The error indicates that the signature file used by the router’s Intrusion Prevention System (IPS) is outdated and needs to be updated. Unlike many other annoying error messages and problems with this brand of routers, the warning discussed in this article is easy to fix by downloading an updated signature file.
IPS Signature Downloads
In a successful attempt to keep the end user experience consistent, the rather horrible products of Linksys have been combined with the rather horrible support of Cisco Systems, so that the solution is somewhat hard to find. At the time of writing this article, the latest version of the IPS signature is 1.42 from June 3rd, 2010. This and other versions can be downloaded here:
After downloading the ZIP file, extract the contained .kr signature rule file. Open the router’s web administration interface and navigate to the IPS → Configuration page where the new rule file can be uploaded.