Linux Monitoring

I hit a login/password on a linux server. Today I prefabricated a typo but to my assail I was ease healthy to login. Now I attending that I crapper login with some countersign that starts with my countersign - in another words, some characters appended to my countersign don’t drive a login error. Any intent ground this would happen?

I hit some pcs to be networked and I requirement internet connectivity ,and hit enter ,dns ,dhcp, scheme hosting and telecommunicate servers.

and I ingest tcp/ip protocols ,so how crapper I fulfill those things with in the linux/unix computer pls indite me info if u undergo substantially most it.
keep in contact ,thanks