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Ethernet Ping (Etherp)

This project allows you to generate and send Ethernet datagrams between two network interfaces. It is actually composed of two programs:

  • etherp-send -- in charge of sending Ethernet frames
  • etherp-recv -- in charge of receiving them

These two tools, used together, can help you to test an Ethernet link or a network driver by detecting loss of frames at different speeds. This is not actually a ping protocol as frames are transfered only on one way (there is no pong).

Let's consider the following test bench with two computers with their Network Interfaces (NIC) directly connected:

__________                __________
|        |                |        |
|  PC1 __|_____       ____|__ PC2  |
|______| NIC1 |-------| NIC2 |_____|
       '------'       '------'

etherp-send usage

etherp-send needs to be run as root (or at least with the CAP_NET_RAW capability) on the machine sending Ethernet frames (let's say PC1 with its MAC address being 00:24:e8:00:00:01):

etherp-send -I eth0 00:24:e8:00:00:01

For more help on usage, run the command etherp-send --help.

etherp-recv usage

etherp-recv also needs to be run as root (or at least with the CAP_NET_RAW capability) on the machine receiving Ethernet frames (PC2):

etherp-recv -I eth0

For more help on usage, run the command etherp-recv --help.

Note that etherp-recv receives all frames with etherp protocol. This means that it would receives frames from several etherp-send instances. However, using several etherp-send instances is not supported by the protocol (cf. next section).

Protocol details

etherp is an Ethernet protocol using the Ethertype 0x4242. Frames contains the following fields:

  • id (4 bytes): identifier (increasing as long as frames are sent)
  • crc32 (4 bytes): Checksum of data
  • stop (1 byte): boolean indicating if this is the last frame sent by the sender
  • data: generated data whose size is the rest of the Ethernet frame

All fields are transmitted using network byte order.