Router (single-thread)

A demonstration of a simple IPv4 router.

  • GitHub Link: https://github.com/packetcord/packetcord.io/tree/main/apps/l3_router
  • Topology File: topology_examples/l3_router.json

Topology diagram

TOP

Steps

Build the project (all examples)

Note: You may need to uncomment the static binding inside the CMakeLists.txt file of the examples:

# Link against cord-flow
target_link_libraries(l3_router_app
    PRIVATE
        cord_flow
        -static # Adding for 'compatibility' when running on Alpile (musl)
)

cd packetcord.io
mkdir build
cd build
cmake .. --fresh
make

Start the topology

Load the exampe topology project file. Then Validate, Generate and Launch the topology.

Inside the shell of Forwarder

./l3_router_app

Result

Open the shells of Node A and Node B. Try to ping each other (192.168.6.100 and 192.168.7.100).

PING 192.168.7.100 (192.168.7.100): 56 data bytes
64 bytes from 192.168.7.100: seq=0 ttl=63 time=0.065 ms
64 bytes from 192.168.7.100: seq=1 ttl=63 time=0.066 ms
64 bytes from 192.168.7.100: seq=2 ttl=63 time=0.101 ms
64 bytes from 192.168.7.100: seq=3 ttl=63 time=0.112 ms

--- 192.168.7.100 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.065/0.086/0.112 ms

Let's also run iperf3 between the other two nodes:

Inside the shell of iperf3 Server

iperf3 -s

Inside the shell of iperf3 Client

iperf3 -c 192.168.8.100

Connecting to host 192.168.8.100, port 5201
[  5] local 192.168.5.100 port 36344 connected to 192.168.8.100 port 5201
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec   191 MBytes  1.60 Gbits/sec  988    100 KBytes       
[  5]   1.00-2.00   sec   212 MBytes  1.77 Gbits/sec  1312   97.6 KBytes       
[  5]   2.00-3.00   sec   225 MBytes  1.89 Gbits/sec  1469    100 KBytes       
[  5]   3.00-4.00   sec   223 MBytes  1.87 Gbits/sec  1357    100 KBytes       
[  5]   4.00-5.00   sec   220 MBytes  1.84 Gbits/sec  1321   96.2 KBytes       
[  5]   5.00-6.00   sec   224 MBytes  1.88 Gbits/sec  1469    103 KBytes       
[  5]   6.00-7.00   sec   224 MBytes  1.88 Gbits/sec  1374    100 KBytes       
[  5]   7.00-8.00   sec   221 MBytes  1.85 Gbits/sec  1394    147 KBytes       
[  5]   8.00-9.00   sec   224 MBytes  1.88 Gbits/sec  1439    100 KBytes       
[  5]   9.00-10.00  sec   224 MBytes  1.88 Gbits/sec  1443    144 KBytes       
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-10.00  sec  2.13 GBytes  1.83 Gbits/sec  13566            sender
[  5]   0.00-10.00  sec  2.13 GBytes  1.83 Gbits/sec                   receiver

Note: You may also run some packet capture (tshark, tcpdump) on the nodes to verify that traffic is forwarded properly between the specified source and destination.

Terminate

Use the Destroy button to terminate the emulation.