Update 6.40pm: Vodafone Ireland said that it has identified the "root cause of an issue that affected some Vodafone mobile data and broadband services this afternoon".
It said that the issue has been fully resolved and normal service has been restored to its customers.
"We thank you for your patience and sincerely apologise for the inconvenience caused," it said.
Vodafone customers had earlier been experiencing connection problems with both mobile and fixed line services.
Update 4.45pm: Vodafone customers are experiencing connection problems with both mobile and fixed line services.
On Twitter the company says it is investigating "potential disruption" that is reported to be affecting number of locations.
Vodafone customers have catalogued connection issues on technology website, Downdector.ie which says the problems have been ongoing since 2.40pm.
According to the website's outage map, the issue is largely affecting Dublin, Cork, Limerick and Galway.
There is no information on how long the issue is expected to last.
Users across the country have been reporting connection problems this afternoon.
We are currently investigating a potential disruption to our fixed and mobile services. We thank you for your patience as we work to get this resolved.— Vodafone Ireland (@VodafoneIreland) June 13, 2019