1.2 - The Windows Network Command Line Flashcards
1
Q
CMD - ipconfig
A
- Most of your troubleshooting starts with your IP address
– Ping your local router/gateway - Determine TCP/IP and network adapter information
– And some additional IP details - View additional configuration details
– DNS servers, DHCP server, etc.
2
Q
CMD - ping
A
- Test reachability
– Determine round-trip time
– Uses Internet Control Message Protocol (ICMP) - One of your primary troubleshooting tools
– Can you ping the host?
3
Q
CMD - netstat
A
- Network statistics
– Many different operating systems -
netstat -a
– Show all active connections -
netstat -b
– Show binaries (Windows) -
netstat -n
– Do not resolve names
4
Q
CMD - nslookup
A
- Lookup information from DNS servers
– Canonical names, IP addresses, cache timers, etc. - Lookup names and IP addresses
– Many different options
5
Q
CMD - net
A
6
Q
CMD - tracert
A
- Determine the route a packet takes to a destination
– Map the entire path - Takes advantage of ICMP Time to Live Exceeded
message
– The time in TTL refers to hops, not
seconds or minutes
– TTL=1 is the first router, TTL=2 is
the second router, etc. - Not all devices will reply with ICMP Time Exceeded
– Some firewalls filter ICMP
– ICMP is low-priority for many devices
7
Q
Flavors of traceroute
A
- Not all traceroutes are the same
– Minor differences in the transmitted payload - Windows commonly sends ICMP echo requests
– Receives ICMP time exceeded messages
– And an ICMP echo reply from the
final/destination device
– Unfortunately, outgoing ICMP is commonly filtered - Some operating systems allow you to specify the
protocol Linux, Unix, macOS, etc. - IOS devices send UDP datagrams over port 33434
– The port number can be changed with extended options
– The mechanics of traceroute
8
Q
CMD - pathping
A
- Combine ping and traceroute
– Included with Windows NT and later - First phase runs a traceroute
– Build a map - Second phase
– Measure round trip time and packet loss at each hop
