Mon Sep 27, 2021 6:43 pm
The first step in diagnosing DHCP is to examine your device's IP address and network settings. You'll need to verify it is using DHCP and not a manually configured address.
If it is configured to use DHCP and has an IP address, note the address, subnet mask, default router and DNS servers.
If a device is unable to get an IP address via DHCP, it will use an automatic private IP address from the address range 169.254.x.y,
The following reasons could cause DHCP errors and compel a device to use a self-assigned IP address:
1.the DHCP server failed;
2.all available addresses have been allocated;
3.the network to the server failed;
4.a configuration change affected DHCP packet relay;
5.a configuration mistake happened during new installation; or
6.media access control (MAC) address filtering is enabled, and the new device isn't included in the server's configuration.
DHCP troubleshooting is challenging because it involves several components: the endpoint device, its network connection, the network devices -- like routers, switches, access points and firewalls -- and the DHCP server itself.