1.3. Configuring the DHCP Client Behavior

A Dynamic Host Configuration Protocol (DHCP) client requests the dynamic IP address and corresponding configuration information from a DHCP server each time a client connects to the network.

Note that NetworkManager calls the DHCP client, dhclient by default.

When a DHCP connection is started, a dhcp client requests an IP address from a DHCP server. The time that a dhcp client waits for this request to be completed is 60 seconds by default. You can configure the ipv4.dhcp-timeout property using the nmcli tool or the IPV4_DHCP_TIMEOUT option in the /etc/sysconfig/network-scripts/ifcfg-ifname file. For example, using nmcli: If an address cannot be obtained during this interval, the IPv4 configuration fails. The whole connection may fail, too, and this depends on the ipv4.may-fail property:

When a dhcp address is acquired and the IP address lease cannot be renewed, the dhcp client is restarted for three times every 2 minutes to try to get a lease from the dhcp server. Each time, it is configured by setting the ipv4.dhcp-timeout property in seconds (default is 60) to get the lease. If you get a reply during your attempts, the process stops and you get your lease renewed.

After three attempts failed:

nmcli connection modify enps1s0 ipv4.dhcp-timeout infinity

~]$ nmcli connection modify enps1s0 ipv4.dhcp-timeout infinity

nmcli connection modify enp1s0 ipv4.address 192.168.122.88/24

~]$ nmcli connection modify enp1s0 ipv4.address 192.168.122.88/24