MAC address changes on every boot

I am running a fully patched Fedora 21 system. We are trying to give it a long term lease in the DHCP server, but the MAC address sent changes on every boot. The MAC address seen at the DHCP server is not actually valid. The DHCP server is like Win2008 Server R2. Any ideas? Regards, Randy --

failure to auto-configure eth1 with ipv6 address

I am running Fedora 14 which is connecting to a Cisco 881 router. eth1 is the connection to the Cisco router, and eth0 will be connected to an internal switch with other clients. I have notices that net.ipv6.conf.eth1.accept_ra is defaulted to 0. I manually set that value to 1 using sysctl -w n