From BiblePortal Wikipedia

Fausset's Bible Dictionary [1]

("house of Rechob, or room".) A place near the valley containing the town Laish or Dan ( Judges 18:28). The modern Hunin, a fortress commanding the plain Huleh in which the city of Dan (Tell el Kady) was. One of Aram's (Syria's) little kingdoms, like Zobah, Maacah, Ishtob; hired by Ammon against David ( 2 Samuel 10:6;  2 Samuel 10:8). Shortened into Rechob ( Numbers 13:21). Being "far from Zidon," it is distinct from the Rehob in Asher, which is not very far from Zidon. Hadadezer king of Zobah was son of Rehob (2 Samuel 8).

Morrish Bible Dictionary [2]

Place in thenorth near Dan, from which perhaps Syrians were hired by the Ammonites against David,  Judges 18:28;  2 Samuel 10:6 . Identified with Hunin, 35 32' E 33 13' N . Some judge that the Syrians came from a different place near the Euphrates.