All air traffic in the Republic of Ireland is stopped, except in Dublin, due to a radar issue.
Due to a Flight Data Processing System (FDPS) failure in Shannon (EISN/SNN), there is a zero-rate regulation. The restriction applies until 23:00 UTC (initially 22:00 UTC).
Dublin is the only airport in the Irish Republic that does not use Shannon’s Air Traffic Control and thus it remains open to the traffic.

From Eurocontrol:
Restriction is applied until 23h00 UTC
Please check headline news for any update
??Attention Passengers??
Air Traffic Control at Ballcasey, Shannon are experiencing issues with their flight radar. Work underway to rectify the situation.Arrivals and Departures at SNN have been suspended until the radar is fully operational.
More updates to follow. pic.twitter.com/tCNh5gAbbA
— Shannon Airport (@ShannonAirport) 2 octobre 2018
There is a significant systems failure with a radar in the west of Ireland resulting in a “zero flow rate” in Irish aerospace at present. @DublinAirport is exempt due to proximity to UK air traffic control. @CorkAirport apologizes for the obvious inconvenience this is causing. pic.twitter.com/hZp8pwz5Wx
— Cork Airport (@CorkAirport) 2 octobre 2018
FYI: “The Airbus A320 family engine access doors case”