CCENT/CCNA-level Challenge Question

NetworkVeteran

You're responsible for the network of a small company, and your boss just decided to hire his nephew as your assistant. He noticed "That STP Thing" was making the network slower, so naturally he disabled it when you were out to lunch, and is very proud of this.

When a host on switch BLD15_1 (botton-left) tries to ARP a host on BLD15_2 (bottom-right), what sorts of.. unfortunate events.. do you expect will happen and why?

mapletune

I'm definitely CCENT level =D entry-level answer coming your way...

Nothing special should happen. STP prevents switching loops. I don't see any redundant link in this topology so all trunk ports should have already been in forward state regardless of STP.

Now, without STP's hello BPDU's... you may or may not claim that the "network is faster" now...

=D hows that for a clueless answer becoming of a beginner!

Roguetadhg

I expect many unfortante events under that scenario, NetworkVeteran. Nephew may be looking for a new job as the boss got tired of covering for him. Also, We may be looking for a job, because the Defecation would hit the Oscillation too much.

Nothing that I could see. STP relies on redundant power supplies, just in case a link fails. Why nothing would happen is because the broadcasts wouldn't bounce back to the switch from another link. If _1 had a direct link to _2, I would expect a broadcast storm.

Rep, NetworkVetern. More questions! More Nephew antics!

NetworkVeteran

mapletune wrote: »

Nothing special should happen. STP prevents switching loops. I don't see any redundant link in this topology so all trunk ports should have already been in forward state regardless of STP.

Quite right!

Now, without STP's hello BPDU's... you may or may not claim that the "network is faster" now...

The network would also converge faster, since ports wouldn't have to waste time transitioning between STP states such as listening, learning, etc. I've seen admins in the real-world disable STP to avoid that impact. Of course, you have to trust that everyone with the ability to add a link understands the implications of doing so, or else chaos will ensue!

Roguetadhg wrote:

I expect many unfortante events under that scenario, NetworkVeteran.. We may be looking for a job, because the Defecation would hit the Oscillation too much.

LoL! Keeping it real.

sratakhin

I also think that nothing special will happen, but... One time, I was playing with a long-range wireless transmitter and receiver. I established a link between two of them and wanted to test if it will work in the network. The receiver was connected to my laptop, and as soon as I connected the transmitter into the wall, people started complaining... It looked like STP problem because once I turned RSTP on, everything worked as it was supposed to. What did I do wrong the first time?

mapletune

thanks for the challenge question though!

quite fun to walk into a random problem and start working on it. hehe =D

lantech

Roguetadhg wrote: »

I expect many unfortante events under that scenario, NetworkVeteran. Nephew may be looking for a new job as the boss got tired of covering for him. Also, We may be looking for a job, because the Defecation would hit the Oscillation too much.

I'm sure it will eventually if he is willing to just turn stuff on and off like that without asking.

Roguetadhg wrote: »

Nothing that I could see. STP relies on redundant power supplies, just in case a link fails. Why nothing would happen is because the broadcasts wouldn't bounce back to the switch from another link. If _1 had a direct link to _2, I would expect a broadcast storm.

Redundant power supplys?

Roguetadhg wrote: »

Rep, NetworkVetern. More questions! More Nephew antics!

I agree, this was pretty fun. It makes you think about what is going on. Very good for those new to networking concepts from the network side of things.

Roguetadhg

About the redundant power supplies...

My mind was on a different issue. Long story short... My OCD kicked in. I got determined to make it work.

I got it done with 2 vampire taps, pliers, and 2 850w power supplies. I sacrificed the Antec 850 by chopping off the end. I should've just snipped the two wires. Oh well. In the second picture shows the Black/Yellow wires going into the vampire taps.

So I've got the 850 powering 2 Harddrive, EVGA 285 GTX. And another one for 480 GTX, 1 harddrive and 1 DVD drive, and the mainboard. I was having issues with just using 1 850 to power a All of that - minus the dvd drive and the 285.

mapletune

holy cows! that's quite an assortment of monitors you have there... O_O!!!

HUGE desk too!!

joluis9

hahahaha.. note the three mouses on the right.

TehToG

Looks like you run all all Microsoft stuff?

Mouse without Borders - YouTube

Might wanna check that out.