Chapter 1 - Packet Forwarding Terms

Question 1

access port

Answer 1

A switch port that is configured for only one specific VLAN and generally
connects end user devices.

Question 2

Address Resolution Protocol (ARP)

Answer 2

A protocol that resolves a MAC address to a specific IP address.

Question 3

broadcast domain

Answer 3

A portion of a network where a single broadcast can be advertised or received.

Question 4

Cisco Express Forwarding (CEF)

Answer 4

A method of forwarding packets in hardware through the use of the FIB and adjacency tables. CEF is much faster than process switching.

Question 5

collision domain

Answer 5

A set of devices in a network that can transmit data packets that can collide
with other packets sent by other devices (that is, devices that can detect traffic from other
devices using CSMA/CD).

Question 6

content addressable memory (CAM)

Answer 6

A high-performance table used to correlate MAC

addresses to switch interfaces that they are attached to.

Question 7

Layer 2 forwarding

Answer 7

The forwarding of packets based on the packets’ destination Layer 2
addresses, such as MAC addresses.

Question 8

Layer 3 forwarding

Answer 8

The forwarding of packets based on the packets’ destination IP
addresses.

Question 9

Forwarding Information Base (FIB)

Answer 9

The hardware programming of a forwarding table.

The FIB uses the RIB for programming.

Question 10

MAC address table

Answer 10

A table on a switch that identifies the switch port and VLAN with
which a MAC address is associated for Layer 2 forwarding.

Question 11

native VLAN

Answer 11

A VLAN that correlates to any untagged network traffic on a trunk port.

Question 12

process switching

Answer 12

The process of forwarding traffic by software and processing by the
general CPU. It is typically slower than hardware switching.

Question 13

Routing Information Base (RIB)

Answer 13

The software database of all the routes, next-hop IP

addresses, and attached interfaces. Also known as a routing table.

Question 14

trunk port

Answer 14

A switch port that is configured for multiple VLANs and generally connects a
switch to other switches or to other network devices, such as firewalls or routers.

Question 15

ternary content addressable memory (TCAM)

Answer 15

A high-performance table or tables that

can evaluate packet forwarding decisions based on policies or access lists.

Question 16

virtual LAN (VLAN)

Answer 16

A logical segmentation of switch ports based on the

broadcast domain.