I changed ISPs recently and I noticed my new one uses dynamic rather than static IPs. So I keep having to authenticate. The first 6 numbers of my IP seem to stay the same, though- it's just the ones at the end that change.
Will authentication eventually recognize it's me or am I just going to have to keep authenticating?
You will be stuck in authentication forever and more. I think it goes the same for any games/clients/anything with 2-step auth; dynamic IP will suffer.