Internet access at NUI Galway is still down following an attempted cyberattack a week ago.
All on-campus web traffic has been disabled, on both wired and wireless connections.
As a result, online activity has been severely impacted, with just some access possible via cloud-based services.
The university says external cyber security experts are working to analyse the attack, contain its impact and safely restore access to systems.
It has described the attack as "sophisticated and human directed".
So far, no evidence has been found to suggest a data breach occurred or that any material has been encrypted.
NUI Galway says it has not received any ransomware request.
The university is liaising with the National Cyber Security Centre, An Garda Síochána and the Department of Higher Education.
There is no timeframe for when full access to IT systems will be restored.
In the meantime, a temporary on-campus wi-fi network will be provided from this evening to allow internet access for students and staff.
The university says the analysis being carried out on its IT network is "an extremely complex and painstaking process".
In a statement this evening, it said it was acutely aware of the disruption being caused by the shutdown.
The President of the NUI Galway Students' Union says the shutdown has caused chaos for all aspects of college life.
Róisín Nic Lochlainn said that as well as disrupting lectures and study plans, problems with the IT system were impacting applications for financial aid and laptop loans for students.
She said this was the last thing her members needed as they tried to negotiate a return to college after the difficulties caused by the pandemic.
Ms Nic Lochlainn said lecturers needed to be mindful of the additional pressures on students and to consider this when it came to assignment or project deadlines.