7.9 KiB
7.9 KiB
Tutorial 1 - Wired Network
Overview
This tutorial will cover some use cases when using a wired 2 node scenario in CORE.
Files
Below is the list of files used for this tutorial.
- 2 node wired scenario
- scenario.xml
- scenario.py
- 2 node wired scenario, with n1 running the "Chat App Server" service
- scenario_service.xml
- scenario_service.py
Running this Tutorial
This section covers interactions that can be carried out for this scenario.
Our scenario has the following nodes and addresses:
- n1 - 10.0.0.20
- n2 - 10.0.0.21
All usages below assume a clean scenario start.
Using Ping
Using the command line utility ping can be a good way to verify connectivity between nodes in CORE.
- Make sure the CORE daemon is running a terminal, if not already
sudop core-daemon - In another terminal run the GUI
core-gui - In the GUI menu bar select File->Open..., then navigate to and select scenario.xml
- You can now click on the Start Session button to run the scenario
- Open a terminal on n1 by double clicking it in the GUI
- Run the following in n1 terminal
ping -c 3 10.0.0.21 - You should see the following output
PING 10.0.0.21 (10.0.0.21) 56(84) bytes of data. 64 bytes from 10.0.0.21: icmp_seq=1 ttl=64 time=0.085 ms 64 bytes from 10.0.0.21: icmp_seq=2 ttl=64 time=0.079 ms 64 bytes from 10.0.0.21: icmp_seq=3 ttl=64 time=0.072 ms --- 10.0.0.21 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 1999ms rtt min/avg/max/mdev = 0.072/0.078/0.085/0.011 ms
Using Tcpdump
Using tcpdump can be very beneficial for examining a network. You can verify traffic being sent/received among many other uses.
- Make sure the CORE daemon is running a terminal, if not already
sudop core-daemon - In another terminal run the GUI
core-gui - In the GUI menu bar select File->Open..., then navigate to and select scenario.xml
- You can now click on the Start Session button to run the scenario
- Open a terminal on n1 by double clicking it in the GUI
- Open a terminal on n2 by double clicking it in the GUI
- Run the following in n2 terminal
tcpdump -lenni eth0 - Run the following in n1 terminal
ping -c 1 10.0.0.21 - You should see the following in n2 terminal
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes 10:23:04.685292 00:00:00:aa:00:00 > 00:00:00:aa:00:01, ethertype IPv4 (0x0800), length 98: 10.0.0.20 > 10.0.0.21: ICMP echo request, id 67, seq 1, length 64 10:23:04.685329 00:00:00:aa:00:01 > 00:00:00:aa:00:00, ethertype IPv4 (0x0800), length 98: 10.0.0.21 > 10.0.0.20: ICMP echo reply, id 67, seq 1, length 64
Editing a Link
You can edit links between nodes in CORE to modify loss, delay, bandwidth, and more. This can be beneficial for understanding how software will behave in adverse conditions.
- Make sure the CORE daemon is running a terminal, if not already
sudop core-daemon - In another terminal run the GUI
core-gui - In the GUI menu bar select File->Open..., then navigate to and select scenario.xml
- You can now click on the Start Session button to run the scenario
- Right click the link between n1 and n2
- Select Configure
- Update the loss to 25
- Open a terminal on n1 by double clicking it in the GUI
- Run the following in n1 terminal
ping -c 10 10.0.0.21 - You should see something similar for the summary output, reflecting the change in loss
--- 10.0.0.21 ping statistics --- 10 packets transmitted, 6 received, 40% packet loss, time 9000ms rtt min/avg/max/mdev = 0.077/0.093/0.108/0.016 ms - Remember that the loss above is compounded, since a ping and the loss applied occurs in both directions
Running Software
We will now leverage the installed Chat App software to stand up a server and client within the nodes of our scenario.
- Make sure the CORE daemon is running a terminal, if not already
sudop core-daemon - In another terminal run the GUI
core-gui - In the GUI menu bar select File->Open..., then navigate to and select scenario.xml
- You can now click on the Start Session button to run the scenario
- Open a terminal on n1 by double clicking it in the GUI
- Run the following in n1 terminal
export PATH=$PATH:/usr/local/bin chatapp-server - Open a terminal on n2 by double clicking it in the GUI
- Run the following in n2 terminal
export PATH=$PATH:/usr/local/bin chatapp-client -a 10.0.0.20 - You will see the following output in n1 terminal
chat server listening on: :9001 [server] 10.0.0.21:44362 joining - Type the following in n2 terminal and hit enter
hello world - You will see the following output in n1 terminal
chat server listening on: :9001 [server] 10.0.0.21:44362 joining [10.0.0.21:44362] hello world
Tailing a Log
In this case we are using the service based scenario. This will automatically start
and run the Chat App Server on n1 and log to a file. This case will demonstrate
using tail -f to observe the output of running software.
- Make sure the CORE daemon is running a terminal, if not already
sudop core-daemon - In another terminal run the GUI
core-gui - In the GUI menu bar select File->Open..., then navigate to and select scenario_service.xml
- You can now click on the Start Session button to run the scenario
- Open a terminal on n1 by double clicking it in the GUI
- Run the following in n1 terminal
tail -f chatapp.log - Open a terminal on n2 by double clicking it in the GUI
- Run the following in n2 terminal
export PATH=$PATH:/usr/local/bin chatapp-client -a 10.0.0.20 - You will see the following output in n1 terminal
chat server listening on: :9001 [server] 10.0.0.21:44362 joining - Type the following in n2 terminal and hit enter
hello world - You will see the following output in n1 terminal
chat server listening on: :9001 [server] 10.0.0.21:44362 joining [10.0.0.21:44362] hello world
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