mirror of
https://gitlab.com/netravnen/NetworkLabNotes.git
synced 2024-11-14 18:49:38 +00:00
43 lines
1.6 KiB
TeX
43 lines
1.6 KiB
TeX
\section{DHCP Process}
|
|
|
|
\fig{dhcp/dhcpdiscoverprocess}{dhcpdiscoverprocess}{DHCP Discover Process}
|
|
|
|
\subsection{DHCP Messages}
|
|
|
|
\begin{itemize}
|
|
\item \textbf{DHCPDECLINE:} Message sent from the client to the server that the address is already in use.
|
|
\item \textbf{DHCPNAK:} The server sends a refusal to the client for request for configuration.
|
|
\item \textbf{DHCPRELEASE:} Client tells a server that it is giving up a lease.
|
|
\item \textbf{DHCPINFORM:} A client already has an IP address but is requesting other configuration parameters that the DHCP server is configured to deliver such as DNS address.
|
|
\end{itemize}
|
|
|
|
\section{DHCP Options}
|
|
|
|
\begin{itemize}
|
|
\item \textbf{43} Vendor-encapsulated option that enables vendors to have their own list of options on the server.
|
|
\item \textbf{69} SMTP server, if you want to specify available SMTP servers to the client.
|
|
\item \textbf{70} POP3 server, if you want to specify available POP3 servers to the client.
|
|
\item \textbf{150} TFTP server that enables your phones to access a list of TFTP servers.
|
|
\end{itemize}
|
|
|
|
\section{DHCP Example Configuration}
|
|
|
|
\subsection{Cisco}
|
|
|
|
\begin{txt}
|
|
ip dhcp excluded-address 192.168.0.254
|
|
!
|
|
ip dhcp pool LAN-1-POOL-DHCP
|
|
network 192.168.0.0 255.255.255.0
|
|
default-router 192.168.0.254
|
|
lease 2 ! set in days
|
|
\end{txt}
|
|
|
|
When configuring a Layer 3 interface as a relay port for DHCP request for a subnet. Set the ip helper command on the interface with one \textit{or} more ip addresses.
|
|
|
|
\begin{txt}
|
|
interface GigabitEthernet 0/3
|
|
ip helper-address 192.168.220.220
|
|
ip helper-address 192.168.222.222
|
|
\end{txt}
|