Use your Cisco router as a primary DNS server

Cisco IOS hints and tricks: Use your Cisco router as a primary DNS server

ip dns server
ip dns primary website.com soa ns.website.com admin@website.com 86400 3600 1209600 86400 

ip host website.com ns ns.website.com
ip host website.com ns ns.isp.com 

ip host website.com mx 10 mail.website.com
ip host website.com mx 20 mail.isp.com

ip host ns.website.com 192.168.0.1 ! router's IP address
ip host www.website.com 192.168.1.1
ip host website.com 192.168.1.1 ! alternate for www.website.com
ip host mail.website.com 192.168.1.2