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Naming convention
We will call the network interface eth0. However, it may be
named differently, especially if you have a different operating system
than Linux. |
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Requirements
- 1 free full duplex network card with RJ45 connector
- 1 Ronja Tetrapolis device
- ping and some packet sniffer (e. g.
tcpdump
or Wireshark
) installed
- Operating system where manual ARP and routing table manipulation
can be done
- A mirror
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Setting full duplex
- Set up the NIC manually to 10Mbps full duplex and switch
autonegotiation off.
Full duplex hints.
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Making ARP table entry
Set up permanent ARP
table entry for the interface eth0, IP address 192.168.1.2 and MAC address
from the paper. (Linux: arp -i eth0 -s
192.168.1.2 MAC_address)
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Packet sniffer
Run a packet sniffer that dumps the packets on screen on interface eth0.
The sniffer must be capable of showing ethernet or IP frames/packets. Linux:
tcpdump
-i eth0 or run Wireshark on eth0. Leave the sniffer running. |
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Without device
- Take another console or open another terminal.
- Make sure nothing is connected to the NIC (network card)
- Start a process that is periodically issuing ICMP Echo
Request packets with 1-second intervals to IP address 192.168.1.2. Linux: ping 192.168.1.2
- The
tcpdump
or Wireshark
should show each ICMP Echo
Request only once, because they are being sent, but not received.
Example
output:
20:27:45.109689 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:46.109692 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:47.109685 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
If tcpdump doesn't see what it should, something in the configuration above
has been done wrong. |
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Connecting Ronja
Tetrapolis Connect Ronja Tetrapolis assembled according to the
picture to the NIC. |
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With device
Now
tcpdump
or Wireshark
should show each ICMP Echo
Request twice (once transmitted, once received). Example
output:
20:27:45.109484 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:45.109689 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:46.109487 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:46.109692 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:47.109480 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
20:27:47.109685 192.168.1.1 > 192.168.1.2: icmp: echo request (DF)
If tcpdump doesn't see double packets but only single, something is wrong with the NIC
(maybe configured to other transceiver than
RJ-45 TP (twisted pair)?), or the DUT failed the test. Otherwise the test
has passed. |
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Estimation
Take a block of packets and manually count how many are double (not lost)
and how many single (lost). Calculate packetloss in percent (%) as
100*single/(double+single).
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