mirror of
https://gitlab.com/netravnen/NetworkLabNotes.git
synced 2024-11-17 18:59:40 +00:00
96 lines
3.2 KiB
TeX
96 lines
3.2 KiB
TeX
\chapter{L2 to L3}
|
|
|
|
\section{Vlan-to-vlan routing}
|
|
|
|
\myquote{}{Guidance and Understanding of the art of Layer 3 networks. Routing between different slash 24\tsq{s}.\\ \textit{Aka. Inter-vlan routing.}}
|
|
|
|
There are different ways to go \tsq{bout} Inter-vlan routing and doing it.
|
|
|
|
\begin{itemize}
|
|
\item \textbf{Some are using:}
|
|
\begin{enumerate}
|
|
\item external router,
|
|
\item switch virtual interfaces\footnote{\texttt{Switches interface -> Vlan interfaces}},
|
|
\item routed ports\footnote{\texttt{Routed interface -> Subinterfaces}},
|
|
\item bridge virtual interface\footnote{\texttt{L3 bridging interface}}
|
|
\end{enumerate}
|
|
\item \textbf{Ways to do it:}
|
|
\begin{enumerate}
|
|
\item router-on-a-stick if the network is running collapsed core or not have a distribution switch in the middle.
|
|
\item (...)
|
|
\end{enumerate}
|
|
\end{itemize}
|
|
|
|
\pagebreak
|
|
|
|
\subsection{Interface configs}
|
|
|
|
\subsubsection{Routed interfaces}
|
|
|
|
\begin{txt}
|
|
interface GigabitEthernet 0/1.10
|
|
encapsulation dot1q 10
|
|
ip address 192.168.0.1 255.255.255.128
|
|
!
|
|
interface GigabitEthernet 0/1.20
|
|
encapsulation dot1q 20
|
|
ip address 192.168.0.129 255.255.255.128
|
|
\end{txt}
|
|
|
|
\subsubsection{Switches interfaces}
|
|
|
|
\begin{txt}
|
|
Vlan10
|
|
name VLAN10
|
|
Vlan20
|
|
name VLAN20
|
|
!
|
|
interface Vlan10
|
|
ip address 192.168.1.1 255.255.255.128
|
|
interface Vlan20
|
|
ip address 192.168.1.129 255.255.255.128
|
|
!
|
|
interface GigabitEthernet 0/2
|
|
switchport mode trunk
|
|
switchport trunk encapsulation dot1q
|
|
switchport trunk allowed vlan 10,20
|
|
\end{txt}
|
|
|
|
\pagebreak
|
|
|
|
\fig{network/routeronastick}{routeronastick}{\bsq{Router on a Stick} concept.}
|
|
|
|
\pagebreak
|
|
|
|
\subsection{? Troubleshooting ?}
|
|
|
|
\begin{enumerate}
|
|
\item \textbf{Missing VLAN:}
|
|
\begin{itemize}
|
|
\item VLAN might not be defined across all the switches.
|
|
\item VLAN might not be enabled on the trunk ports.
|
|
\item Ports might not be in the right VLANs.
|
|
\end{itemize}
|
|
\item \textbf{Layer 3 interface misconfiguration:}
|
|
\begin{itemize}
|
|
\item Virtual interface might have the wrong IP address or subnet mask.
|
|
\item Virtual interface might not be up.
|
|
\item Virtual interface number might not match with the VLAN number.
|
|
\item Routing has to be enabled to route frames between VLAN.
|
|
\item Routing might not be enabled.
|
|
\end{itemize}
|
|
\item \textbf{Routing protocol misconfiguration:}
|
|
\begin{itemize}
|
|
\item Eyery interface or network needs to be added in the routing protocol.
|
|
\item The new interface might not be added to the routing protocol.
|
|
\item Routing protocol configuration is needed only if VLAN subnets need to communicate to the other routers, as previously
|
|
mentioned in this chapter.
|
|
\end{itemize}
|
|
\item \textbf{Host misconfiguration:}
|
|
\begin{itemize}
|
|
\item Host might not have the right IP address or subnet mask.
|
|
\item Each host has to have the default gateway that is the SVI or Layer 3 interface to communicate with other networks and VLAN.
|
|
\item Host might not be configured with the default gateway.
|
|
\end{itemize}
|
|
\end{enumerate}
|