Specifying the source interface for DNS packets
This task enables the device to always use the primary IP address of the specified source interface as the source IP address of outgoing DNS packets. This feature applies to scenarios in which the DNS server responds only to DNS requests sourced from a specific IP address. If no IP address is configured on the source interface, no DNS packets can be sent out.
When sending an IPv6 DNS request, the device follows the method defined in RFC 3484 to select an IPv6 address of the source interface.
You can configure only one source interface on the public network or a VPN instance. You can configure the source interface for both public network and VPN instances.
To specify the source interface for DNS packets:
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Specify the source interface for DNS packets. | dns source-interface interface-type interface-number [ vpn-instance vpn-instance-name ] | By default, no source interface for DNS packets is specified. If you execute the command multiple times, the most recent configuration takes effect. If you specify the vpn-instance vpn-instance-name option, make sure the source interface is on the specified VPN. |