A Dynamic Host Configuration Protocol (DHCP) cheat sheet can be handy for managing and troubleshooting DHCP services on a network. Here are cheat sheet of DHCP commands and concepts:
Basic DHCP Concepts
DHCP Server:
- The server that dynamically assigns IP addresses and other network configuration information to devices on a network.
- DHCP Client:
- A device that requests and receives network configuration information from a DHCP server.
Commands and Configuration
Install DHCP Server (on Linux):
sudo apt-get install isc-dhcp-server
Start DHCP Server (on Linux):
sudo service isc-dhcp-server start
Stop DHCP Server (on Linux):
sudo service isc-dhcp-server stop
Restart DHCP Server (on Linux):
sudo service isc-dhcp-server restart
Configuration File (dhcpd.conf)
Location (on Linux):
/etc/dhcp/dhcpd.conf
Example dhcpd.conf:
subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.10 192.168.1.50;
option routers 192.168.1.1;
option domain-name-servers 8.8.8.8, 8.8.4.4;
}
DHCP Lease Management
View Active Leases (on Linux):
cat /var/lib/dhcp/dhcpd.leases
Release DHCP Lease (on Linux):
sudo dhclient -r
DHCP Relay
Install DHCP Relay (on Linux):
sudo apt-get install isc-dhcp-relay
Configure DHCP Relay (on Linux):
- Edit
/etc/default/isc-dhcp-relay
and setSERVERS
to the DHCP server’s IP.
Troubleshooting
Check DHCP Server Status (on Linux):
sudo service isc-dhcp-server status
Check DHCP Server Logs (on Linux):
tail -f /var/log/syslog
Test DHCP Configuration (on Linux):
sudo dhcpd -t
Renewing DHCP Lease
Renew DHCP Lease (on Linux):
sudo dhclient -r
sudo dhclient
DHCP Options
Common DHCP Options:
option subnet-mask
,option routers
,option domain-name-servers
, etc.
DHCPv6
Install DHCPv6 Server (on Linux):
sudo apt-get install isc-dhcp-server6
Configure DHCPv6 (on Linux):
- Edit
/etc/dhcp/dhcpd6.conf
.
This cheat sheet provides a quick reference for managing and troubleshooting DHCP services. Always refer to the specific documentation for your DHCP server implementation for more details and advanced configurations.