Chapter 6: Introduction to the Internet Protocol

What Transport layer protocol does a DNS server use?

Both TCP and UDP! A DNS server uses TCP port 53 for zone transfers and UDP port 53 for name resolutions. Notice that DNS uses both TCP and UDP. Whether it opts for one or the other depends on what it's trying to do.

Name the protocol that uses both TCP ports 20 and 21.

FTP uses both TCP ports 20 and 21 for the data channel and the control channel, respectively.

What protocol is at the heart of the ping and tracert commands in a Windows operating system?

ICMP is the protocol that the ping and tracert commands rely on. If you're having trouble getting pings and traceroutes through a router, you might need to check if ICMP is being allowed through.

Which protocol dynamically reports errors to source hosts by using IP directly to build packets?

ICMP uses IP directly to build error-reporting packets that are transmitted back to the originating source host when issues arise during the delivery of data packets. ICMP is also used during Ping and some Traceroute operations.

Which ports does the protocol MGCP use?

MGCP uses ports 2427 and 2727.

What could cause a server that you can ping not to provide the particular TCP/IP service, such as FTP, HTTP and so on, that you expect it to offer?

Quite simply, the service might not be running currently on that server. Another possibility might be that a firewall between the client and the server has blocked the protocol in question from passing.

What is the well-known port number for RPC?

RDP uses port 3389.

What well-known port numbers do DMTP, POP3, RDP, and IMAP4 servers use?

SMTP uses TCP port 25, POP3 uses TCP port 110, RDP uses TCP port 3389, and IMAP4 uses TCP port 143.

Which destination Transport layer protocol and port number does a TFTP client use to transfer files over the network?

TFTP servers respond to UDP messages sent to port 69.

What would an ARP destination MAC address appear as?

This would be a Layer 2 broadcast, or FF:FF:FF:FF:FF:FF.