R0106-HP MSR Router Series Layer 3 - IP Services Configuration Guide(V7)

Tasks at a

lance

(Optional.) Configuring DNS spoofing

(Optional.) Specifying the source interface for DNS packets

(Optional.) Configuring the DNS trusted interface

(Optional.) Setting the DSCP value for outgoing DNS packets

Configuring the IPv4 DNS client

Configuring static domain name resolution

Static domain name resolution allows applications such as Telnet to contact hosts by using host names

instead of IPv4 addresses.

Follow these guidelines when you configure static domain name resolution:

• On the public network or a VPN, each host name maps to only one IPv4 address. The most recent

configuration for a host name takes effect.

• You can configure the following:

{ IPv4 DNS entries for the public network and up to 1024 VPNs.

{ A maximum of 1024 IPv4 DNS entries for the public network or each VPN.

To configure static domain name resolution:

Step Command Remarks

1. Enter system view.

system-view N/A

2. Configure a mapping between a host

name and an IPv4 address.

ip host host-name ip-address

[ vpn-instance vpn-instance-name ]

By default, no mapping

between a host name and

an IPv4 address is

configured.

Configuring dynamic domain name resolution

To use dynamic domain name resolution, configure DNS servers so that DNS queries can be sent to a

correct server for resolution. A DNS server manually configured takes precedence over the one

dynamically obtained through DHCP, and a DNS server configured earlier takes precedence. A name

query is first sent to the DNS server that has the highest priority. If no reply is received, it is sent to the DNS

server that has the second highest priority, and so on.

In addition, you can configure a DNS suffix that the system automatically adds to the provided domain

name for resolution. A DNS suffix manually configured takes precedence over the one dynamically

obtained through DHCP, and a DNS suffix configured earlier takes precedence. The DNS resolver first

uses the suffix that has the highest priority. If the name resolution fails, the DNS resolver uses the suffix that

has the second highest priority, and so on.

Configuration guidelines

Follow these guidelines when you configure dynamic domain name resolution:

• You can specify DNS server IPv4 addresses as follows: