active_probing

Active probing

To run measurements between any two ASes, we must use a dedicated container called MEASUREMENT. After activating port forwarding, you can access the measurement container over port 2099:

ssh -p 2099 root@<your_server_domain>

You can find the password in the file groups/ssh_measurement.txt. It should be distributed to all students such that they can access the MEASUREMENT container. In the MEASUREMENT container, we provide a script called launch_traceroute.sh that relies on nping and that can be used to launch traceroutes between any pair of ASes. For example if you want to run a traceroute from AS1 to AS2, simply run the following command:

root@ba1ccfaf2f55:~# ./launch_traceroute.sh 1 2.108.0.1
Hop 1:  1.0.199.1 TTL=0 during transit
Hop 2:  179.0.0.2 TTL=0 during transit
Hop 3:  2.0.1.2 TTL=0 during transit
Hop 4:  2.0.6.2 TTL=0 during transit
Hop 5:  2.108.0.1 Echo reply (type=0/code=0)

where 2.108.0.1 is an IP address of a host in AS2. You can see the path used by the packets to reach the destination IP.

By default, the MEASUREMENT container is connected to the router MILA in every transit AS (see the l3_routers.txt configuration file). If for one AS none of the routers is connected to the MEASUREMENT container, you cannot run a traceroute from that AS via the MEASUREMENT container. Using the default configuration files this is the case for the the Tier1 and Stub ASes. In other words, by default the MEASUREMENT container can only launch traceroutes from student ASes.