2069 For some hints on how to configure these virtual interfaces, see

  2070 \autoref{sec:eoe-config}.

  2071 

  2197 \subsection{EoE Interface Configuration}

  2198 \label{sec:eoe-config}

  2199 

  2200 The configuration of the EoE network interfaces is a matter of using standard

  2201 Linux networking infrastructure commands like \lstinline+ifconfig+,

  2202 \lstinline+ip+ and \lstinline+brctl+. Though this lies not in the scope of

  2203 this document, some hints and examples are provided in this section.

  2204 

  2205 In the below examples it is assumed, that there are two slaves (0 and 1) with

  2206 EoE support in the bus. The first decision to make is whether to use a bridged

  2207 or routed environment.

  2208 

  2209 \paragraph{Bridging} A common solution is to create a bridge containing all EoE

  2210 interfaces:

  2211 

  2212 \begin{lstlisting}

  2213 $ `\textbf{brctl addbr br0}`

  2214 $ `\textbf{ip addr add 192.168.100.1/24 dev br0}`

  2215 $ `\textbf{brctl addif br0 eoe0s0}`

  2216 $ `\textbf{brctl addif br0 eoe0s1}`

  2217 \end{lstlisting}

  2218 

  2219 The above example allows to access IPv4 nodes using subnet 192.168.100.0/24

  2220 connected to the EtherCAT bus via EoE. Please note, that the example only

  2221 contains ad-hoc configuration commands: If the bus topology changes, the EoE

  2222 interfaces are re-created and have to be added to the bridge again. Therefore

  2223 it is highly recommended to use the networking configuration infrastructure of

  2224 the used Linux distribution to store this configuration permanently, so that

  2225 appearing EoE devices are added automatically.

  2226 

  2227 \paragraph{Routing} Another possibility is to create an IP subnet for each EoE

  2228 interface:

  2229 

  2230 \begin{lstlisting}

  2231 $ `\textbf{ip addr add 192.168.200.1/24 dev eoe0s0}`

  2232 $ `\textbf{ip addr add 192.168.201.1/24 dev eoe0s1}`

  2233 $ `\textbf{echo 1 > /proc/sys/net/ipv4/ip\_forward}`

  2234 \end{lstlisting}

  2235 

  2236 This example is again only an ad-hoc configuration (see above). Please note,

  2237 that it is necessary to set the default gateways properly on the IP nodes

  2238 connected to the EoE slaves, if they shall be able to communicate between the

  2239 different EoE interfaces / IP networks.

  2240 

  2241 \paragraph{Setting IP Parameters} If IP address and other parameters of the

  2242 EoE remote nodes (not the EoE interfaces on the master side) have to be set,

  2243 this can be achieved via the \lstinline+ethercat ip+ command-line tool (see

  2244 \autoref{sec:ipparam}).

  2245 

  2495 \label{sec:ipparam}

  2496 

  2497 Slaves can have own IP stack implementations accessible via EoE. Since some of

  2498 them do not provide other mechanisms to set IP parameters (because they only

  2499 have an EtherCAT interface), there is a possibility to set the below

  2500 parameters via EoE:

  2501 

  2502 \begin{itemize}

  2503 \item Ethernet MAC address\footnote{The MAC address of the virtual EoE remote

  2504 interface, not the one of the EtherCAT interface.},

  2505 \item IPv4 address,

  2506 \item IPv4 subnet mask,

  2507 \item IPv4 default gateway,

  2508 \item IPv4 DNS server,

  2509 \item DNS host name.

  2510 \end{itemize}