4 Troubleshooting IP Addressing

Question 1

What does pinging 127.0.0.1 do ?

Answer 1

This is the diagnostic, or loopback address, and if you get a successful ping, your IP stack is considered initialized; If it fails, then you have an IP stack failure and need to reinstall TCP/IP on the host

Question 2

Cisco way of troubleshooting connectivity:

Answer 2

Ping loopback address: 127.0.0.1
Ping local host NIC IP (localhost)
Ping default gateway (router)
Ping device you are trying to connect to

Question 3

What does the ‘ping’ command do ?

Answer 3

Uses ICMP echo request and replies to test if a node IP stack is initialized and alive on the network.

Question 4

What does the ‘tracert’ command do ?

Answer 4

Displays the list of routers on a path to a network destination by using TTL time-outs and ICMP error messages. This command won’t work on a Cisco router (use traceroute).

Question 5

What does the ‘arp -a’ command do ?

Answer 5

Displays IP-to-MAC-address mappings on a Windows PC.

Question 6

What does the ‘show ip arp’ command do ?

Answer 6

Same function as arp -a, but displays the ARP table on a Cisco router.

Question 7

What does the ‘ipconfig /all’ command do ?

Answer 7

Used only from a Windows command prompt; shows you the PC network configuration.

Question 8

What does the ‘ipconfig’ command do ?

Answer 8

Used by MAC and Linux to get the IP address details of the local machine

Question 9

What does the ‘ipconfig getifaddr en0’ command do ?

Answer 9

Used to find your IP address if you are connected to a wireless network or use en1 if you are connected to an Ethernet for MAC or Linux.

Question 10

What does the ‘curl ifconfig.me’ and ‘curl ipecho.net/plain ; echo’ command do ?

Answer 10

This command will display your global Internet IP address in Terminal for MAC or Linux.