Usually, you would use an external Windows, or Unix or Linux server to do that. Now, you will not usually want a Cisco router to be a DNS Server. ip host : This command enters address records for everything that you want it to be able to resolve.ip dns server: This command configures it as a DNS server.If you wanted a router to be your DNS Server, then you would enter those same commands in the DNS Client configuration, plus the following commands: ip domain-list : This command is used to lookup additional DNS suffixes.ip domain-lookup: This command allows it to lookup at a DNS server.If you did want it to be able to resolve hostnames, the commands to enter are: Often when we're working on a router, we're always going to be working with IP addresses. This is only if you need the router itself to be able to resolve FQDNs to hostnames.
You don't need to set the router as a DNS Client for DNS traffic to pass through it. For example, you maybe want to ping LinuxA from the router, then you would need to set it as a DNS Client.
