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Elastic Compute Service

Network connection issue

Solution for network unavailability on Linux systems

This topic describes the solution for network disconnection on a Linux system due to failure to renew IP leases when corresponding network processes are missing under the DHCP configuration.

Prerequisites

Before you modify the configuration or data of an instance, we recommend that you create a snapshot to improve fault tolerance and ensure data security.

Procedure

Execute the ps -ef |grep [$network process] command to check whether the network process exists. If the corresponding network process does not exist, this indicates a potential risk. Continue with the following operations.

Corresponding network processes (network configuration method: DHCP) are as follows:

OS version	Network process
CentOS 6/7	/sbin/dhclient
Debian 8/9/10
Ubuntu 14/16
CentOS 8	/usr/sbin/NetworkManager
Ubuntu 18/20	/lib/systemd/systemd-networkd
SUSE Linux	/usr/lib/wicked/bin/wickedd-dhcp4

Execute one of the following commands to restart the network service.

Network service names vary across Linux systems and even between versions of the same system. Specific network names and commands to restart them are as follows:

warning

Restarting the network service may cause short-term network disruption and impact business operations. Restart the network service at an appropriate time.

OS	Version	Network service	Command to restart network service
CentOS	6	Network	service network restart
		7	Network	service network restart
		8	NetworkManager	systemctl restart NetworkManager
Debian	8	networking	systemctl restart networking
		9	networking	systemctl restart networking
		10	networking	systemctl restart networking
Ubuntu	14	networking	service networking restart
		16	networking	systemctl restart networking
		18	systemd-networkd	systemctl restart systemd-networkd
		20	systemd-networkd	systemctl restart systemd-networkd

Last updated: 2026.06.18 17:49:51