How can I contact someone in Dublin Ireland?

My mentor in Chicago growing up who I have not seen in 50 years I found on Linkedin but unable to connect so there must be another way if he is not on social media.

OneDrop2021-04-07T16:36:14Z

How do you know he's in Dublin and do you have an address or is Dublin all you know?

J2021-04-07T15:18:10Z

https://www.eirphonebook.ie/q/name/
http://world.192.com/europe/ireland

Mark2021-04-07T15:03:10Z

There is something called a "telephone" and also directory assistance, but if he is totally on mobile, I am not sure if such numbers are listed.  (It's been a LONG time since I used d.a., like at least 10 years, so that policy might have changed.)