I found the root problem, according to systemd-resolved log, the dns servers list is too long, dns resolution is not working anymore.
May 13 13:41:07 ubuntu systemd-resolved[1109]: Failed to read DNS servers for interface eno1, ignoring: Argument list too long
May 13 13:41:07 ubuntu systemd[1]: Started Network Name Resolution.
May 13 13:41:09 ubuntu systemd-resolved[1109]: Failed to read DNS servers for interface eno1, ignoring: Argument list too long
I found the root problem, according to systemd-resolved log, the dns servers list is too long, dns resolution is not working anymore.
May 13 13:41:07 ubuntu systemd- resolved[ 1109]: Failed to read DNS servers for interface eno1, ignoring: Argument list too long resolved[ 1109]: Failed to read DNS servers for interface eno1, ignoring: Argument list too long
May 13 13:41:07 ubuntu systemd[1]: Started Network Name Resolution.
May 13 13:41:09 ubuntu systemd-