I thought "A Soldier's Song"" was/is the official Irish Anthem, but largely superseded by "Ireland's Call", and I notice at both rugby tests between the All Blacks and Ireland currently in NZ it was the latter song that was sung.
That is the anthem of the Republic of Ireland/EIRE/Free state. Irelands Call was written to be an inclusive anthem which recognises the presence of players from NI. Soldier song is only played at home games; away games gets the Ireland Call treatment.