dns forward retry-number

Function

The dns forward retry-number command sets the number of times for the device to retransmit query requests to the destination DNS server.

The undo dns forward retry-number command restores the default retransmission count.

By default, the retransmission count is 2.

Format

dns forward retry-number number

undo dns forward retry-number

Parameters

Parameter	Description	Value
number	Specifies the number of times for the device to retransmit query requests to the destination DNS server.	The value is an integer from 0 to 15.

Views

System view

Default Level

2: Configuration level

Usage Guidelines

The mode for a device to select the destination DNS server can be auto and fixed. For how a device sends DNS request packets to the destination DNS server in each mode and the corresponding precautions, see dns-server-select-algorithm.

If the number of times for the device to retransmit DNS request packets to each destination DNS server is relatively large and the packet retransmission timeout period is relatively long, the time for the DNS client to wait for the response from the DNS server is too long. However, the request timeout period of the DNS client is shorter, so that the DNS client fails to properly receive response packets from the server. To enable the DNS server to rapidly respond DNS request packets, you can run the dns forward retry-number and dns forward retry-timeout commands to adjust the number of times for the device to retransmit DNS request packets to each DNS server and the packet retransmission timeout period for ensuring that the DNS client can properly receive response packets from the server.

You need to consider the number of times for the device to retransmit DNS query requests to the destination DNS server, retransmission timeout period, and mode for the device to select the DNS server into consideration before configuring the query timeout period on a device.

When the mode for a device to select the destination DNS server is auto, the query timeout period of a DNS device is calculated as follows: (Number of retransmission times + 1) x Retransmission timeout period
When the mode for a device to select the destination DNS server is fixed, the query timeout period of a DNS device is calculated as follows: (Number of retransmission times + 1) x Retransmission timeout period x Number of DNS servers

Example

# Set the retransmission count that the device sends query packets to the destination DNS server to 1.

<sysname> system-view
[sysname] dns forward retry-number 1