QID:NA378

[robertrose6]

How do you change the MAC address into numbers so that you can add it to the Priority?


Thank You

[gtrunner]

The mac address and priority are to separate things that make up the Bridge ID.

In STP the switches look at the priority first, the lowest becomes the root bridge. If all or some of the priority numbers are the same (this will happen most of the time *default priority= 32768* )  they then look at the mac addresses, the lowest mac address becomes the root bridge.

you can change the mac address of a switch but its almost never done and way outside the scope of this test. so for this test you cant change the mac address of any device.

did this answer your question?

[Pharcyde256]

The question is to determine which switch would become the root bridge given the Bridge ID's.

The issue is due to the answer being a switch with priority of 4096 and MAC address of 2424.3535.1111, when there are two switches with priorities of 32768.

[forumsupport]

The root switch is the switch with the lowest numeric value for the bridge ID. Because the two-part bridge ID starts with the priority value, essentially the switch with the lowest priority becomes the
root. For example, if one switch has priority 100, and another switch has priority 200, the
switch with priority 100 wins, regardless of what MAC address was used to create the
bridge ID for each bridge/switch.

If priorities are equal then the switch with the lowest numerical value of MAC address wins.

4096 < 32768
2424.3535.1111 < ABAB.CDCD.EFEF

[JohnWilliams]

There are many online resources you can find on internet for CCNA training. I think it is better to go for online training. Many online resources provides cheap training where you can find variety of books and helpful material. I did CCNA last 2 years ago and got an excellent score and now I am preparing for advance CCIE program. Here in this case I am planning for a online training for this program.

[anitosin]

@ John Williams:

Hi John,

Could you please recommend the best materials for CCNP certification?

Many thanks