rdate.cpanel.net: name or service not known

Hello, i've have a VPS with WHM-cPanel. From yesterday the VPS is not working fine. in the boot process there are some error like these: --- vps35188 login: rdate: rdate.cpanel.net: name or service not known --- url_helper.py[warning]: calling 'http://169.254.169.254/2009-04-04/meta-data/instance-id' failed [5/120s]: unexpected error ['NoneType' obj ect has no attribute 'status_code'>
how can I fix it? note: in the last days I have updated the system, without errors and it works fine until last night.