What is localhost and why would ping localhost fail?
What is the similarity between "ping" & "traceroute" ? How is traceroute able to find the hops.
What is the command used to show all open ports and/or socket connections on a machine?
Is 300.168.0.123 a valid IPv4 address?
Which IP ranges/subnets are "private" or "non-routable" (RFC 1918)?
What is a VLAN?
What is ARP and what is it used for?
What is the difference between TCP and UDP?
What is the purpose of a default gateway?
What is command used to show the routing table on a Linux box?
A TCP connection on a network can be uniquely defined by 4 things. What are those things?
When a client running a web browser connects to a web server, what is the source port and what is the destination port of the connection?
How do you add an IPv6 address to a specific interface?
You have added an IPv4 and IPv6 address to interface eth0. A ping to the v4 address is working but a ping to the v6 address gives yout the response sendmsg: operation not permitted. What could be wrong?
What is SNAT and when should it be used?
Explain how could you ssh login into a Linux system that DROPs all new incoming packets using a SSH tunnel.
How do you stop a DDoS attack?
How can you see content of an ip packet?
What is IPoAC (RFC 1149)?

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