4 Network Configuration Problems Free Online FlashCards

What does ipconfig /all help you inspect?

On Windows, ipconfig /all shows adapter addresses, subnet masks, gateways, DHCP status, DNS servers, and DNS suffixes.

What do an IP address and subnet mask determine together?

The address identifies an interface, while the mask or prefix length determines which destinations are local and which require a router.

What can an unexpected 169.254.x.x IPv4 address indicate?

It often means the client did not obtain a DHCP lease. Check the link, VLAN, DHCP availability, and relay path before assigning a static address.

What is the default gateway's role?

It is the next hop for destinations without a more specific route. A wrong gateway can leave local communication working while blocking access to other networks.

Why does a failed ping not always prove a gateway is unreachable?

A router or firewall may block ICMP even when other traffic works, so a failed ping does not by itself prove the gateway is unreachable.

What is a VLAN, and what is generally needed for communication between VLANs?

A VLAN is a logical Layer 2 network. Devices in different VLANs generally need a router or Layer 3 switch to communicate.

What should you verify about a trunk carrying a client's VLAN?

The required VLAN must be allowed across each trunk, and trunk settings—including the native VLAN where used—must match at both ends.

How does a router normally choose among multiple matching routes?

The most specific matching prefix is normally preferred when several routes match a destination.

Why is a return route needed for successful communication?

The destination network needs a route back to the client's subnet; without it, communication can time out even if packets reach the destination.

What does a missing response from a hop in tracert not necessarily mean?

Routers may not answer trace probes, so a missing response at one hop does not prove that hop is broken.

What should you investigate when a service works by IP address but not by host name?

Check name resolution, including the configured DNS servers and DNS suffix; the issue may be DNS even when IP connectivity works.

How can an overly broad subnet mask cause selective connectivity failures?

An overly broad mask can make the client treat some destinations as local and contact them directly instead of sending traffic to a router, causing selective failures.