server named: client 18.104.22.168#64003: zone transfer `somedomain.com/AXFR/IN` denied
This log entry shows that the DNS server is denying a system from performing a zone transfer. A zone transfer is a request to access all DNS data for a domain. This is normal for a trusted DNS server to do that is authoritative for the domain, but not normal or required for any other server.
Attackers may use this method to perform reconnaissance on servers before an attack.