MED - Multi-Exit Discriminator

Question 1

What is MED?

Answer 1

BGP supported directive designed top provide preference directives for traffic entering your network.

Question 2

What is First Valid Path?

Answer 2

Current best path

Question 3

What is the routing metric BGP and most networks use?

Answer 3

Most specific wins - 192.168.0.1/32 > 192.168.0.0/24

Question 4

What metric does BGP use to determine the best path between two routes to the same destination?

Answer 4

Weight - highest weight wins

Question 5

Is weight universally supported?

Answer 5

No, it is vendor specific. Cisco may support it, others may not.

Question 6

What is Local_pref (local preference)

Answer 6

Routes that are advertised internally. - Default 100 and highest wins.

Question 7

if all things and local_pref are equal, what metric is the tiebreaker?

Answer 7

Local Origination

Question 8

If all things and local_pref are equal, what is the tiebreaker?

Answer 8

AS_Path - Shortest is preferred. This is also the metric that can be manipulated to make another AS change its route into your network.

Question 9

Manipulating the AS_Path only effects your own routing, and that of networks directly connected to yours?

Answer 9

False: This can have a global reach since changes are advertised to other networks not directly peered.

Question 10

After AS_Path, what is the next tiebreaker?

Answer 10

Origin_code - IGP < EGP < Incomplete

Question 11

After Origin_CODE, what is the next tiebreaker?

Answer 11

MED Metric Attribute - Lowest preferred

Question 12

is a MED readvertised to other routers?

Answer 12

No, it is a metric only available to directly peered routers.

Question 13

True or False the highest MED attribute is prefered?

Answer 13

False. Lowest prefered