5 Network Services and Name Resolution Free Online FlashCards

What network configuration does DHCP provide?

DHCP automatically provides clients with network configuration, such as an IP address, subnet mask, default gateway, and DNS-server addresses.

What does DNS do?

DNS resolves names to records and addresses, allowing clients to use names to find network destinations.

What does DORA stand for in DHCP?

DORA is Discover, Offer, Request, Acknowledgement: the common IPv4 DHCP exchange.

Which UDP ports does DHCP normally use?

DHCP normally uses UDP ports 67 and 68.

What is the role of a DHCP relay agent?

A DHCP relay agent, often called an IP helper, forwards requests when clients and the DHCP server are on different subnets.

What can a 169.254.x.x client address indicate?

A missing address or an automatic link-local address such as 169.254.x.x can indicate that the client did not obtain a usable DHCP lease; it does not prove the server is down.

Why might a DHCP outage not immediately disconnect every client?

A client with a valid existing lease may keep communicating for a time. DHCP trouble may first appear when a device joins, reconnects, or renews its lease.

What does working IP access but failing hostname access suggest?

If access by IP works but access by hostname fails, investigate DNS configuration, records, caching, or DNS traffic.

Which ports and protocols are used for DNS queries?

DNS queries commonly use UDP port 53; TCP port 53 is also used.

What is the difference between a DNS timeout and “name does not exist”?

A timeout suggests no usable response, possibly because the server is unreachable, stopped, or blocked by a path or firewall problem. A “name does not exist” response means the queried server has no matching DNS data for that name.

Why does a successful ping not prove an application service works?

A successful ping does not prove an application service works: ICMP may be blocked, and the service may listen on a different port or interface.

How can the number and location of affected clients guide diagnosis?

One affected client suggests a local adapter or configuration problem; many affected clients on one subnet suggest a shared service, relay, VLAN, or gateway issue.