Modifying a Subnet

Scenarios

Modify the subnet name and DNS server address.

Procedure

1. Log in to the management console.

2. Click in the upper left corner and choose Network > Virtual Private Cloud.

   The Virtual Private Cloud page is displayed.

3. In the navigation pane on the left, choose Virtual Private Cloud > Subnets.

   The Subnets page is displayed.

4. In the subnet list, locate the target subnet and click its name.

   The subnet details page is displayed.

5. On the Summary tab, click on the right of the parameter to be modified and modify the parameter as prompted.

   Table 1 Parameter descriptions

   Parameter	Description	Example Value
   Name	The subnet name. The name can contain a maximum of 64 characters, which may consist of letters, digits, underscores (_), hyphens (-), and periods (.). The name cannot contain spaces.	Subnet
   DNS Server Address	By default, two DNS server addresses are configured. You can change them as required. A maximum of two DNS server addresses are supported. Use commas (,) to separate every two addresses. DNS server addresses allow ECSs in a VPC subnet to communicate with each other using private domain names. You can also directly access cloud services through private DNS servers. If you want to use other public DNS servers for resolution, you can change the default DNS server addresses. A maximum of five DNS server IP addresses can be configured. Multiple IP addresses must be separated using commas (,).	100.125.x.x
   DHCP Lease Time	The period during which a client can use an IP address automatically assigned by the DHCP server. After the lease time expires, a new IP address will be assigned to the client. Unit: Day or hour If the time period is changed, the new lease time takes effect when the instance (such as an ECS) in the subnet is renewed next time. You can wait for the instance to be renewed automatically or manually modify the lease time. If you want the new lease time to take effect immediately, manually renew the lease or restart the ECS.	-
   NTP Server Address	The IP address of the NTP server. This parameter is optional. You can configure the NTP server IP addresses to be added to the subnet as required. The IP addresses are added in addition to the default NTP server addresses. If you do not specify this parameter, no additional NTP server IP addresses will be added. A maximum of four unique NTP server IP addresses can be configured. Multiple IP addresses must be separated by a comma (,). If you add or change the NTP server addresses of a subnet, you need to renew the DHCP lease for or restart all the ECSs in the subnet to make the change take effect immediately. If the NTP server addresses have been cleared out, restarting the ECSs will not help. You must renew the DHCP lease for all ECSs to make the change take effect immediately.	192.168.2.1
   Description	Supplementary information about the subnet. This parameter is optional. The description can contain a maximum of 255 characters and cannot contain angle brackets (< or >).	-

6. Click OK.