banned ips due to Tor?

Hello everybody.
I’ve been running a tor internal relay since some months and i’ve a multi homed system.
Single ethernet interface with multiple ip addresses.
Today i discovered that my provider banned all of them.
I’ve other ones i just tried and they still work.
In the process of isolating the cause for that, I’ve been thinking of tor.
Since i didn’t forced an outbound address in torrc, my question is: does tor cycle through all of the available ips to make its outgoing connections?
That could explain what happened.
Thanks in advance!