Which file contains the list of DNS services SLES will contact?

The file that contains the list of DNS servers SLES will contact is /etc/resolv.conf. This file specifies one or more nameserver addresses that will be used to resolve hostnames to IP addresses. It may also contain other options such as search domains, sort lists, etc. The /etc/resolv.conf file can be generated automatically by network configuration tools or edited manually by the administrator. References:https://documentation.suse.com/sles/15-SP3/html/SLES-all/sec-network-dns.html#sec-network-dns-resolv.conf