Paddy,

No it does not, ccna/ccnp certs are only valid for three years. Generally ccna's are renewed if you had completed a major cert like the ccnp before your ccna expires.

Usually a major certification at the prof'nal or expert level will automatically renew an associate cert as long as the associate has not expired.

You can always confirm by asking directly Cisco certification online support link.

http://ciscocert.custhelp.com/cgi-bin/ciscocert.cfg/php/enduser/std_alp.php?p_sid=whGeBXlj

Regards