From Ireland and travel through FRA a few times a year with LH. Yes to passport and security. I've no idea why but they make you do security again. They don't if you are doing intra Schengen. PAssport obviously makes sense if coming from outside Schengen
I never had a problem with Frankfurt till it all went wrong on me last week. EI always on the apron but the LH A321 often, but not always, uses an airbridge. Last week it didn't. So landing on the distant runway ten minutes late, a fifteen minute taxi in, plus a bus ride along with passport and security (by far the quickest part of the whole transfer) meant an hour wasn't enough. There was a flight an hour later to where I was headed so I was ok but somehow I doubt there's an LH plane to SFO an hour after your one.
It depends which departure from DUB you're on. If it's the early one you should be ok but the 12.10 p.m. has been running late a bit recently depending on the day.
If your connection time is an hour or less then it'll be touch and go I'm afraid. I mentioned to the gate supervisor of my second flight last week that LH probably needed to stop selling anything under 90 minute connections from non-Schengen countries through FRA and she agreed. It clearly happens a lot.
Last edited by alserire; 28th Jun 2016 at 13:27.