Is it permissible to pray two Rak'ahs in the mosque before the Eid prayer?

No supererogatory prayer is prescribed before the Eid prayer, unless the Eid prayer is performed in a mosque. In that case, one who enters the mosque before the Imam arrives should pray two rak'ahs as a greeting to the mosque, due to the general nature of the Prophet's (peace be upon him) saying: "If any of you enters the mosque, let him pray two rak'ahs before he sits down." However, if the Eid prayer is performed outside the mosque, then the greeting to the mosque prayer is not performed.