What solution ensures clients of the Samba server can look up all DNS records?

The correct answer is based on how DNS resolution is managed in a Samba environment. When the additional DNS server is configured directly in the Samba configuration file (smb.conf), the Samba server becomes responsible for handling DNS queries from its clients. This setup allows clients to query the Samba server for DNS information, enabling them to look up all DNS records effectively through the Samba infrastructure.

By integrating DNS capabilities directly into Samba, you ensure a seamless user experience where clients do not need to worry about other DNS configurations; they can simply use the Samba server to resolve any DNS records. This is particularly beneficial in mixed environments where Samba may need to provide name resolution for both Windows and Linux clients.

The other options present various configurations that do not centralize DNS query handling in the same way. For instance, configuring an additional DNS server in /etc/resolv.conf may help individual clients resolve names but does not empower the Samba server to provide DNS records directly. Similarly, having both Samba and another DNS server configured on clients may lead to conflicts or reduced efficiency in DNS resolution without creating a cohesive system where Samba actively serves DNS records. Lastly, using WINS with a DNS proxy implies that Samba functions as an intermediary, rather than being a primary resolver for DNS queries.