The addressing, naming, and time services that let clients find and use network resources.
Core network services supply the information a client needs to participate in a network: an address and route, names for services, and time that can be trusted across systems. A failure in one of these services may look like a broad connectivity failure even when the physical and routed path is intact.
| Service | Primary role | A useful diagnostic distinction |
|---|---|---|
| DHCP | Supplies IPv4 configuration such as an address, prefix length, default gateway, and DNS servers | A client can have a valid lease but still fail to resolve names or reach a service |
| SLAAC | Lets an IPv6 host configure addresses from router advertisements | SLAAC is not DHCPv4 with a different address format; router advertisements are central to it |
| DHCPv6 | Can provide IPv6 configuration, including stateful address allocation or supplemental options | It can coexist with SLAAC depending on the network design |
| DNS | Resolves names to addresses and other resource records | Direct-IP access can work while name-based access fails |
| NTP | Synchronizes system clocks | Correct routing does not guarantee correct time |
| PTP | Provides higher-precision time synchronization where the architecture supports it | It serves a different precision and deployment need than general-purpose NTP |
| NTS | Adds cryptographic protection to NTP client-server time synchronization | It protects time synchronization; it is not a replacement for NTP itself |
1IPv4 address: 192.168.50.44
2Prefix length: /24
3Default gateway: 192.168.50.1
4DNS server: 192.168.50.10
This configuration supports local subnet communication and gives the client a route and name server, but it does not prove that the gateway, DNS server, or application is reachable.
When a client cannot use a named service, work from its dependencies rather than changing network equipment at random:
Time service failures can create confusing secondary symptoms. Large clock differences can invalidate certificates, complicate incident timelines, and disrupt authentication protocols that depend on freshness or valid time windows.
For the records that identify authoritative DHCP scopes, DNS zones, and address assignments, see Network Documentation, Diagrams, and IPAM.