:The Linux network process does not exist

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Problem description

If the corresponding network process does not exist in the instance and the network configuration is DHCP, the lease of IP addresses cannot be renewed after the lease expires. Then the instance connection fails.

Solution

Alibaba Cloud reminds you that:

• Before you perform operations that may cause risks, such as modifying instance configurations or data, we recommend that you check the disaster recovery and fault tolerance capabilities of the instances to ensure data security.
• You can modify the configurations and data of instances including but not limited to Elastic Compute Service (ECS) and Relational Database Service (RDS) instances. Before the modification, we recommend that you create snapshots or enable RDS log backup.
• If you have authorized or submitted sensitive information such as the logon account and password in the Alibaba Cloud Management Console, we recommend that you modify such information in a timely manner.

Troubleshooting

You can run the ps -ef | grep [$network process] command to check whether the network process exists. If the corresponding network process does not exist, there are potential risks. The network processes corresponding to each system (using DHCP as the network configuration method) are as follows:

/sbin/dhclient

/usr/sbin/NetworkManager

/lib/systemd/systemd-networkd

/usr/lib/wicked/bin/wickedd-dhcp4 

Solution

If the system network service is abnormal or the network service process is absent, restart the network service to restore it. Different Linux have different network service names and different system versions have different network services. The name of the specified network service and the command for restarting the network service are as follows:

Warning: restarting the network service may cause the network to be interrupted for a short time.

service network restart

systemctl restart network

systemctl restart NetworkManager

systemctl restart networking

systemctl restart networking

systemctl restart networking

service networking restart

systemctl restart networking

systemctl restart systemd-networkd

systemctl restart systemd-networkd

systemctl restart wicked

systemctl restart wicked

systemctl restart wicked

systemctl restart systemd-networkd

Application scope

• Elastic Compute Service