When a router can't send an IP datagram any further
When a router's memory buffer for receiving incoming datagrams is full
Each IP datagram is allotted a certain number of routers, called hops, to pass through. If it reaches its limit of hops before arriving at its destination, the last router to receive that datagram deletes it. The executioner router then uses ICMP to send an obituary message, informing the sending machine of the demise of its datagram
Ping (Packet Internet Groper)
Used to check the physical and logical connectivity of machines on an internetwork
Used to discover the path a packet takes as it traverses an internetwork
Reverse Address Resolution Protocol (RARP)
discovers the identity of the IP address for diskless machines by sending out a packet that includes its MAC address
Address Resolution Protocol (ARP)
Used to find the hardware address from a known IP address
Proxy Address Resolution Protocol (Proxy ARP)
The technique in which one host, usually a router, answers ARP requests intended for another machine. By "faking" its identity, the router accepts responsibility for routing packets to the "real" destination. Proxy ARP can help machines on a subnet reach remote subnets without the need to configure routing or a default gateway.
32-bit logical numeric identifier assigned to each machine on an IP network
one digit, 1 or 0
8 bits (with parity)
numerical identifier for a remote network; uniquely identifies each network
address used by applications and hosts to send information to all nodes on a network
may be depicted in dotted-decimal, hex, or binary
uniquely identifies each machine on a network
What is the Class C address range in decimal and in binary?
What layer of the DoD model is equivalent to the Transport layer of the OSI model?
What is the valid range of a Class A network address?
What is the 127.0.0.1 address used for?
Loopback or diagnostics
How do you find the network address from a listed IP address?
Turn all host bits off
How do you find the broadcast address from a listed IP address?
Turn all host bits on
What is the Class A private IP address space?
10.0.0.0 through 10.255.255.255
What is the Class B private IP address space?
172.16.0.0 through 172.31.255.255
What is the Class C private IP address space?
192.168.0.0 through 192.168.255.255
What are all the available characters that you can use in hexadecimal addressing?
0-9 and A, B, C, D, E, and F
What is the decimal and hexadecimal equivalent of the binary number 10011101?
157 & 0x9D
Which of the following allows a router to respond to an ARP request that is intended for a remote host?
You want to implement a mechanism that automates the IP configuration, including IP address, subnet mask, default gateway, and DNS information. Which protocol will you use to accomplish this?
What protocol is used to find the hardware address of a local device?
Which of the following are layers in the TCP/IP model?
Application, Transport, Internet
Which class of IP address provides a maximum of only 254 host addresses per network ID?
Which of the following describe the DHCP Discover message?
It uses FF:FF:FF:FF:FF:FF as a layer 2 broadcast; It uses UDP as the Transport layer protocol
Which layer 4 protocol is used for a Telnet connection?
Which statements are true regarding ICMP packets?
They can provide hosts with information about network problems; They are encapsulated within IP datagrams
Which of the following services use TCP?
SMTP, FTP, HTTP
Which of the following services use UDP?
DHCP, SNMP, TFTP
Which of the following are TCP/IP protocols used at the Application layer of the OSI model?
Telnet, FTP, TFTP
If you use either Telnet or FTP, which is the highest layer you are using to transmit data?
The DoD model (also called the TCP/IP stack) has four layers. Which layer of the DoD model is equivalent to the Network layer of the OSI model?
Which of the following is a private IP address?
What layer in the TCP/IP stack is equivalent to the Transport layer of the OSI model?
Which statements are not true regarding ICMP packets?
UDP will send an ICMP Information request message to the source host; ICMP guarantees datagram delivery; ICMP is encapsulated within UDP datagrams
What is the address range of a Class B network address in binary?
Which of the following protocols use both TCP and UDP?