vRtrAdvPrefixPreferredLifetime 1.3.6.1.4.1.6527.3.1.2.3.23.1.7

The remaining length of time in seconds that this prefix will continue to be preferred, i.e. time until deprecation. A value of 4,294,967,295 represents infinity. The address generated from a deprecated prefix should no longer be used as a source address in new communications, but packets received on such an interface are processed as expected.