What is an inode?
Which file to edit to define which partition are mounted at startup?
Describe DNS

What are the TCP flags?
What are the HTTP headers?

What is the OSI model and what are the different layers?

Type of firewall and difference between stateful and stateless

What is ARP and how it is used

Which layer is living a hub, a switch, a router

What is a network, what defines a network.
What are the private IP addresses range

Difference between TCP and UDP?

Difference between ext2 and ext3?
What is file journalisation?

How arp tables are updated on switches?

Different type of spanning tree protocols?

What is the sub-netting? What is the super netting?

What is the MTU
what is the df option (do not fragment)
What is the IPSec port
What is the frame size?
Meaning of ECN: Explicit Congestion Notification

What are the FTP commands?

snmp poll and trap

what is http-keepalive?

How is a TCP session initiated/closed? What is the 3-way handshake?

How the diffie hellman authentication works?
Explain SSL

What is the forking in Linux?

Default port for remote logging?

How to display the routing table in Linux?
What is the difference between a symbolic and an hard link?