This topic describes how to add the DNS server address and security group rules to a Linux ECS or BMS to ensure successful download of the Agent installation package and successful monitoring data collection. This topic takes an ECS as an example. The operations for BMSs are similar.
You can modify the DNS configuration of an ECS in either of the following ways: command line and management console. Choose a method based on your habits.
DNS and security group configuration are intended for the primary NIC.
The following describes how to add the DNS server address to the resolv.conf file using command lines.
To use the management console, see Modifying the DNS Server Address (Management Console).
The value of nameserver varies depending on the region.
ru-moscow: 100.125.13.59
Figure 1 Adding DNS server addresses (Linux)

The following describes how to modify the DNS server address of an ECS in the region on the management console. The operations for BMSs are similar.
On the ECS console, click the target ECS name to view its details.
The Virtual Private Cloud page is displayed.
Figure 2 VPC

next to DNS Server Address in the Gateway and DNS Information area.Set the DNS server address to the value of nameserver in 3.
The new DNS server address is applied after the ECS or BMS is restarted.
The following describes how to modify security group rules for an ECS on the management console. The operations for BMSs are similar.
The security group list is displayed.
For BMSs:
Priority | Action | Type | Protocol & Port | Destination IP Address | Description | |
|---|---|---|---|---|---|---|
1 | Allow | IPv4 | TCP | 80 | 100.125.0.0/16 | Used to download the Agent installation package from an OBS bucket to an ECS or BMS and obtain the ECS or BMS metadata and authentication information. |
1 | Allow | IPv4 | TCP | 53 | 100.125.0.0/16 | Used by DNS to resolve domain names, for example, resolve the OBS domain name when you are downloading the Agent installation package, and resolve the Cloud Eye endpoint when the Agent is sending monitoring data to Cloud Eye. |
1 | Allow | IPv4 | UDP | 53 | 100.125.0.0/16 | Used by DNS to resolve domain names, for example, resolve the OBS domain name when you are downloading the Agent installation package, and resolve the Cloud Eye endpoint when the Agent is sending monitoring data to Cloud Eye. |
1 | Allow | IPv4 | TCP | 443 | 100.125.0.0/16 | Used to collect monitoring data to Cloud Eye. |