The fastest feasible technology for human-carrying ships is the fission fragment rocket, with a burnout velocity of about 0.1c. That's 40 years to Proxima b. An 11 ly trip to this world would not be feasible, because a multi-generational ship with the payload fraction needed to hit 0.1c is not feasible.
Probes can be much lighter, enabling higher payload fractions and faster trips.
https://en.wikipedia.org/wiki/Project_Orion_(nuclear_propuls...
Right now, between 10,000 and 100,000 years.
Under 100 years is probably outside of possible without some fundamental breakthrough which we can't forsee. (and at this point it matters from whose perspective the time is measured)
Between 100 and 10,000 is the realm of at least plausible science fiction.
We don't _have_ any technology for interstellar travel because nobody has developed it.