Christchurch's Hillmorton High School has been forced to close for two days because rats have damaged a fibre cable and the internet is down.
Student were asked to work from home on Monday and Tuesday while repairs were done at the school.
In a school newsletter, principal Sam Ainsworth said staff discovered the problem on Monday morning.
"Unfortunately, we have a cabling issue with a core fibre cable connection that has been severely damaged by rodents over the weekend. This fibre connection is our main connection to the school and as a result of the damage, I have concerns about managing the health and safety of large numbers of students," he said.
"While I know that this will not be a popular decision for all and may be challenging for many families, it is a decision we have not taken lightly."
Ainsworth said the school's servers were down, there was no Wifi network or phone system and staff had lost access to CCTV.
Any assessments due to take place on Tuesday would be rescheduled, he said.
"We are confident and hopeful that Wednesday will run as normal. The cabling company will spend all day [Tuesday] running a new cable.
"We are confident that even if the network is not fully up and running, we will have had time to make provisions to ensure students can return to school."
The Ministry of Education said its property adviser was in contact with the school.
"The school has already engaged with their IT provider and the cabling company, who we understand has repairs under way," it said.


