The R215 is the former R132 (itself formerly N1) through Dundalk, and former N52 between Dundalk and Ardee. The R132 moving to the Eastern bypass following the downgrading of the N52 north of Ardee. While not specifically listed in the Statutory Instrument that lists all R roads, it is mentioned several times in the descriptions of the R roads that end on it.
It should be noted that no signing changes have taken place in Dundalk, and as such the R215 is still signed as the R132. The number is, however, shown on some official maps.