"quarantine" a relay if its ip address was changed ?
Summary
After a change of the ip address a relay should be set to "do not use" for a certain time frame.
Details
i. setup a new tor relay i. wait few days till bandwidth measurement is made and first weights are assigned i. move it inside the network of a victim i. establish a connection to it with a Tor client
If the victim uses blacklist to filter out connection attempts from Tor servers then the update of those blacklists might be too late. Especially if RELATED,ESTABLISHED connections are untouched the already established connection would stay.