Routing

Question 1

At what OSI layer do routers operate?

Answer 1

Layer 3

Question 2

Are routers for or against broadcast traffic?

Answer 2

Against.

Question 3

T/F: Routers support translation of different Layer 3 protocols.

Answer 3

True.

Question 4

T/F: Routers provide intelligent data forwarding based on Layer 2 protocols and routing tables that use Layer 2 addresses.

Answer 4

False. Layer 3 addresses and protocols are used.

Question 5

80/20 assumes what percent for subnet and what for WAN?

Answer 5

80% on subnet, 20% to WAN through the router.

Question 6

T/F: routers can efficiently manage traffic that falls outside of the 80/20 rule.

Answer 6

False. Other solutions may be needed when the 80/20 rule does not apply.

Question 7

Name 3 new tasks that routers perform that may degrade their efficiency.

Answer 7

• running firewalls
• network address translation (NAT)
• IP accounting

Question 8

What are two other names for a Layer 3 switch?

Answer 8

Switching router, routing switch

Question 9

Match:

1. Router
2. Layer 3 switch

a. software decisions
b. hardware decisions

i. faster
ii. slower

> more intelligent

Answer 9

1. a. ii.

Question 10

What is route-once switch-many routing?

Answer 10

Layer 3 switch determines a best path to a destination, and assumes all other packets to the same destination will use the same path

Question 11

Name up to 10 awesome things the L3 switch does.

Answer 11

• provides routing functions optimized for today’s LAN
• provides wire-speed performance
• uses routing tables
• translates L3 protocols
• forwards INTER-subnet traffic based on network layer addressing (L3 routing)
• forwards INTRA-subnet traffic based on MAC addresses (L2 switching)
• provides wire-speed forwarding (eliminate router as bottleneck)
• adapts to traffic conditions based on forwarding rules
• maintains broadcast traffic breakwall