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RSTP port question
This question is from the Hucaby BCMSN cd...
What 802.1w port type has a segment's best cost to reacg the root bridge?
a) Backup
b) Alternate
c) Designated
d) Forwarding
e) Disabled
f) Root
I do not see how the answer isn't f) Root, and yet David Hucaby suggests it's c.
From the answer's explanation:
Designated:
A designated port is the non-root port on a network segment with the lowest cumulative cost to the root bridge.
Root:
A root port is the port on a switch that has the lowest cumulative cost to the root bridge.
Help me understand... what's the difference? Why am I wrong thinking that the Root port is the right answer.
Thanks,
mike
What 802.1w port type has a segment's best cost to reacg the root bridge?
a) Backup
b) Alternate
c) Designated
d) Forwarding
e) Disabled
f) Root
I do not see how the answer isn't f) Root, and yet David Hucaby suggests it's c.
From the answer's explanation:
Designated:
A designated port is the non-root port on a network segment with the lowest cumulative cost to the root bridge.
Root:
A root port is the port on a switch that has the lowest cumulative cost to the root bridge.
Help me understand... what's the difference? Why am I wrong thinking that the Root port is the right answer.
Thanks,
mike
There are only 10 kinds of people... those who understand binary, and those that don't.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project.
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dtlokee
Member Posts: 2,378 ■■■■□□□□□□
mikearama wrote:This question is from the Hucaby BCMSN cd...
What 802.1w port type has a segment's best cost to reacg the root bridge?
a) Backup
b) Alternate
c) Designated
d) Forwarding
e) Disabled
f) Root
I do not see how the answer isn't f) Root, and yet David Hucaby suggests it's c.
From the answer's explanation:
Designated:
A designated port is the non-root port on a network segment with the lowest cumulative cost to the root bridge.
Root:
A root port is the port on a switch that has the lowest cumulative cost to the root bridge.
Help me understand... what's the difference? Why am I wrong thinking that the Root port is the right answer.
Thanks,
mike
The key is the question said "segment" not "switch". If ti were switch then I would agree it's the root port, but for a segment the designated port has the lowest cost to the root.The only easy day was yesterday! -
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networker050184
Mod Posts: 11,962 Mod
Tricky question, don't expect anything less from Cisco
If you read that one too fast you will pick root port. I usually read the question twice to make sure. An expert is a man who has made all the mistakes which can be made. -
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mikearama
Member Posts: 749
So a follow up question... is the connection from any switch to the root switch (assuming directly connected) not also called a segment?There are only 10 kinds of people... those who understand binary, and those that don't.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project. -
Optionsnetworker050184
Mod Posts: 11,962 Mod
Yes, what is the port advertising the lowest root path cost? The port on the root (root path cost 0) which is the designated port for the segment.An expert is a man who has made all the mistakes which can be made.
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Optionsmikearama
Member Posts: 749
Ahhh... nice. Thanks.There are only 10 kinds of people... those who understand binary, and those that don't.
CCIE Studies: Written passed: Jan 21/12 Lab Prep: Hours reading: 385. Hours labbing: 110
Taking a time-out to add the CCVP. Capitalizing on a current IPT pilot project. -
Optionsdtlokee
Member Posts: 2,378 ■■■■□□□□□□
Remember all the ports on the root switch will be designated (well except for the odd occurance where you connect a port on the root switch back to another port on the root switch.)The only easy day was yesterday!
