Troubleshoot IP Configuration & Local Network Connectivity

What do unplugged or disconnected for a local network adapter mean you should check?

The cable or wireless network configuration

What does limited connectivity mean on a Windows local network adapter?

The adapter is set to obtain an address automatically, but no DHCP server can be contacted

What address might an adapter use during limited connectivity?

An APIPA address in the 169.254.x.y range or an address specified as an alternate configuration in IPv4 properties

What does no Internet access mean on a Windows local network adapter?

The IP configuration is valid for the local network, but Windows cannot identify a working Internet connection

How does Windows test Internet access?

By attempting a connection to www.msftconnecttest.com and checking that DNS resolves the IP address correctly

What could no Internet access indicate?

A problem with the router, with DNS, or with both

What does ipconfig show when used without switches?

The IP address, subnet mask, and default gateway for all network adapters to which TCP/IP is bound

What extra details does ipconfig /all display?

DHCP and DNS servers, MAC address, and NetBIOS status

Which ipconfig command releases a DHCP-assigned IP address?

ipconfig /release AdapterName

Which ipconfig command renews a DHCP lease?

ipconfig /renew AdapterName

What do ipconfig /displaydns and ipconfig /flushdns do?

Display the DNS resolver cache; clear the DNS resolver cache

What does the hostname command return?

The name configured on the local machine

What can pinging another computer's IP address confirm?

Basic IP connectivity

What can pinging a known computer name confirm?

DNS or name connectivity

What does a Windows network reset do?

Clears custom adapter configurations and network connections, including VPN connections, which must be reconfigured after the reset

What might the problem location be if the link and IP configuration both seem correct?

Somewhere in the overall network topology rather than with the local machine

Why is trying to use file shares, printers, or email not the best low-level network test?

There could be an application fault rather than a network fault

What is the ping command used to test?

Whether a host can communicate with another host on the same network or on a remote network

What does pinging 127.0.0.1 verify?

TCP/IP is installed and loaded correctly

What does pinging your workstation's IP address verify?

It was added correctly and helps check for possible duplicate IP addresses

What does pinging the default gateway verify?

It is up and running and that you can communicate with a host on the local network

What does pinging a remote host IP address verify?

You can communicate through the router

What does a successful ping reply include?

Reply from IP Address and the time it takes for the host's response to arrive

What can round-trip time in milliseconds help diagnose?

Latency problems on a link

What does ping -t do in Windows?

Sends an unlimited number of packets

How do you stop a ping -t test?

CTRL + C

What happens if you ping a DNS name or FQDN when a DNS server is unavailable?

It will not work

What do the -4 and -6 switches do with ping?

Force the DNS query to use IPv4 or IPv6, respectively

What does Reply from SenderIP Destination unreachable usually mean on the same local network segment?

The sending host gets no response to ARP probes

What is the most likely cause of Reply from SenderIP Destination unreachable?

The destination host is disconnected or configured as non-discoverable

What could Reply from SenderIP Destination unreachable indicate if the host is confirmed up?

IP misconfiguration such as duplicate addresses or an incorrect subnet mask

What does Reply from GatewayIP Destination unreachable mean?

The gateway router has no forwarding information for that IP address

What does Reply from GatewayIP Destination unreachable indicate?

Misconfiguration of the router or destination network

What does Request timed out usually mean?

The probe was sent via the gateway, but no response was received

What is the most likely cause of Request timed out?

The destination host is down or configured not to respond