1.5 - The Windows Network Command Line

OS and what does ipconfig do and what are the first things you check with it?

WINDOWS

• Determines TCP/IP and network adapter information.

• Start here for most troubleshooting:

  • check IP address, gateway, DNS servers, and DHCP server.

  • Ping your local router/gateway to verify connectivity.

What OS and what does ping do and what protocol does it use?

Windows & Linux & macOS

Tests reachability to a host and determines round-trip time.

Uses Internet Control Message Protocol (ICMP).

One of your primary troubleshooting tools — if you can't ping the host, connectivity is broken.

What do the flags -a, -b, and -n do with netstat?

-a shows all active connections.

-b shows binaries/processes that own connections (Windows only).

-n does not resolve names (displays IPs only, faster).

What does nslookup do and when would you use it?

• Queries DNS servers to lookup canonical names, IP addresses, and cache timers.

• Use it to troubleshoot DNS resolution issues and verify DNS server responses.

How do you view network resources with the net command?

net view \\<servername> lists shared resources on a specific server.

net view /workgroup:<workgroupname> lists all computers in a workgroup.

How do you map a network share to a drive letter?

net use h: \\<servername>\<sharename> maps the shared folder to drive letter h: (or any letter you choose).

How do you view user account info and reset passwords with net?

net user <username> displays local user info.

net user <username> * /domain resets password for a domain user (prompts for new password).

What does tracert do and what protocol does it use?

• Maps the entire route a packet takes to reach a destination.

• Uses ICMP Time to Live Exceeded messages.

• Shows each hop (router) along the path

What does TTL represent in tracert and how does it work?

• TTL (Time To Live) counts hops, not seconds or minutes.

• TTL=1 is the first router, TTL=2 is the second router, etc.

• Each hop decrements TTL by 1 until it reaches 0.

Why might tracert not show all hops or the destination?

• Not all devices reply to ICMP Time Exceeded messages.

• Some firewalls filter ICMP traffic.

• ICMP is low-priority for many devices, so they may silently drop it.

How does Windows tracert differ from Linux/Unix/macOS traceroute?

• Windows sends ICMP echo requests and receives ICMP time exceeded messages plus an ICMP echo reply from the destination.

• Linux/Unix/macOS often send UDP datagrams over port 33434 (changeable with options).

• Outgoing ICMP is commonly filtered, making UDP-based traceroute more reliable.

What does pathping do and how does it differ from ping and tracert?

• Combines ping and tracert functionality.

• Phase 1: runs tracert to build a map of the route.

• Phase 2: measures round-trip time and packet loss at each hop. Included with Windows NT and later.