DNS

This chapter describes how to configure the DNS parameters.

DNS (Domain Name Service) provides name to IP address mapping:

  • the DNS client performs name resolution on Turbo Router only,
  • the DNS proxy makes it easier to configure the LAN.

Configuring the DNS client

You can configure the DNS client in the dns context.

  • Specify the address of a DNS server to be used for local resolution (on Turbo Router):

    router{myconfig-dns}nameserver A.B.C.D|X:X::X:X
    
    A.B.C.D

    IPv4 address of a DNS server.

    X:X::X:X

    IPv6 address of a DNS server.

  • Delete a name server from the DNS server list:

    router{myconfig-dns}delete nameserver A.B.C.D|X:X::X:X
    
  • Delete all configured DNS server addresses:

    router{myconfig-dns}delete nameserver all
    
  • Specify the domain name for local resolution:

    router{myconfig-dns}domainname NAME
    
    NAME

    Domain name for local resolution (e.g., 6wind.com).

Configuring the DNS proxy

Overview

A DNS proxy is used to forward requests and replies between clients and servers when they are not on the same physical subnetwork.

The DNS proxy listens for DNS request and responses. When a request is received, it is forwarded to the right DNS server. When a reply is received from a server, it is forwarded to the client who made the initial request.

The DNS proxy needs at least the IP address of a reachable DNS server.

Enabling and disabling the DNS proxy

The DNS proxy is disabled by default.

  • Enable the DNS proxy:

    router{myconfig-dns}proxy enable
    
  • Disable the DNS proxy:

    router{myconfig-dns}proxy disable
    

Configuring the DNS proxy

  • Add a DNS server for the DNS proxy:

    router{myconfig-dns}forwarder A.B.C.D|X:X::X:X
    
    A.B.C.D

    IPv4 address of the DNS forwarder

    X:X::X:X

    IPv6 address of the DNS forwarder

  • Delete a DNS server:

    router{myconfig-dns}delete forwarder A.B.C.D|X:X::X:X
    
  • Delete all configured forwarders:

    router{myconfig-dns}delete forwarder all
    

    Example

    router{myconfig-dns}forwarder 1.1.1.1
    router{myconfig-dns}delete forwarder 1.1.1.1
    

Configuring logs

  • Log events from the DNS proxy:

    router{myconfig-dns}log dns SESSION SEVERITY
    
    SESSION

    Name of an existing log session

    SEVERITY

    System logging severity level

  • Stop logging events from the DNS proxy:

    router{myconfig-dns}delete log dns SESSION
    

Displaying DNS information

  • Display the status of the DNS proxy service:

    router{}show service
    
  • Display the current DNS information stored on Turbo Router:

    router{}show dns
    

    Example

    router{}show service
    Service  SSH             is active
    Service  TELNET          is inactive
    Service  HTTP            is inactive
    Service  IP Forwarding   is inactive
    Service  IPv6 Forwarding is active
    Service  SNMP            is inactive
    Service  NAT             is inactive
    Service  DNS-PROXY       is active
    Service  FILTER          is inactive
    Service  RIP             is inactive
    Service  RIPng           is inactive
    Service  OSPFv2          is inactive
    Service  OSPFv3          is inactive
    Service  BGP             is inactive
    Service  ISIS            is inactive
    Service  DHCPSERVER      is inactive
    Service  DHCP            is inactive
    Service  DHCP RELAY      is inactive
    Service  NTP             is active
    Service  CRON            is inactive
    
    router{}show dns
    # STATIC DNS
       10.10.10.1
       192.168.0.1
    

Displaying the DNS configuration

  • Display the DNS configuration:

    router{myconfig}display dns
    

    or

       router{myconfig-dns}display
    
    .. rubric:: Example
    
    .. code-block:: cli
    
        router{myconfig-dns}display
           # DNS STATMENTS
             proxy enable
           # DOMAIN NAME
             domainname 6wind.com
           # NAME SERVERS
             nameserver 192.168.0.1
           # FORWARDERS
             forwarder 10.10.10.1
           # LOG
             log dns session1 info
        router{myconfig-dns}
    

Configuration example

  • Configure a local nameserver and domain name:

    router{myconfig}dns
    router{myconfig-dns}nameserver 192.168.0.1
    router{myconfig-dns}domainname 6wind.com
    
  • Enable the DNS proxy and configure a static forwarder:

    router{myconfig-dns}proxy enable
    router{myconfig-dns}forwarder 10.10.10.1