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spt diameter
- Thread starter iwanthome
- Start date
- Thread starter
- #3
eurobadger
Technical User
Hi
I looked on CCO, and found this:
Use the diameter keyword to specify the Layer 2 network diameter (the maximum number of bridge hops between any two end stations in the network). When you specify the network diameter, a switch automatically picks an optimal hello time, forward delay time, and maximum age time for a network of that diameter. This can significantly reduce the spanning tree convergence time.
It seems that Cisco's answer to the question in this case is two.
EB
I looked on CCO, and found this:
Use the diameter keyword to specify the Layer 2 network diameter (the maximum number of bridge hops between any two end stations in the network). When you specify the network diameter, a switch automatically picks an optimal hello time, forward delay time, and maximum age time for a network of that diameter. This can significantly reduce the spanning tree convergence time.
It seems that Cisco's answer to the question in this case is two.
EB
The diameter of this network is 3.
You have to consider the worst or maximum case. In this case, an end station attached to switch 1 and an end station connected to switch 3. For End station 1 to "talk" to end station 3 to packet needs to traverse three bridges (switches).
Cheers,
If everything is coming your way then you're in the wrong lane.
You have to consider the worst or maximum case. In this case, an end station attached to switch 1 and an end station connected to switch 3. For End station 1 to "talk" to end station 3 to packet needs to traverse three bridges (switches).
Cheers,
If everything is coming your way then you're in the wrong lane.
eurobadger
Technical User
Hi
Sorry, fynx, but I agree with dmedinag.
If we consider what the STP network is, then the end stations are not part of it. The Bridge hops that Cisco's website refers to are those between bridges.
In the topology:
PC1---SW1----SW2----SW3---PC2
only the links SW1----SW2 and SW2----SW3 are bridge hops.
EB
Sorry, fynx, but I agree with dmedinag.
If we consider what the STP network is, then the end stations are not part of it. The Bridge hops that Cisco's website refers to are those between bridges.
In the topology:
PC1---SW1----SW2----SW3---PC2
only the links SW1----SW2 and SW2----SW3 are bridge hops.
EB
Yeah OK - I get your point. I was not trying to mislead anyone into thinking end stations play a part, just using them as an example of what bounds the STP domain. That and I read Cisco's explanation a little differently - but yup, you're right it does make sense to count bridge "hops" rather than bridges.
Regards...
If everything is coming your way then you're in the wrong lane.
Regards...
If everything is coming your way then you're in the wrong lane.
- Thread starter
- #9
somebody told me:
diameter of the STP domain is defined:
The maximum number of bridges between any two points of attachment of end stations.
See for details.
So my network diameter is 3.
thanks everyone!
diameter of the STP domain is defined:
The maximum number of bridges between any two points of attachment of end stations.
See for details.
So my network diameter is 3.
thanks everyone!
eurobadger
Technical User
Hi all,
I followed the link that iwanthome found. In there it says:
diameter of the STP domain (dia): this is the maximum number of bridges between any two points of attachment of end stations. The IEEE considers a maximum diameter of seven bridges.
I guess that this clarifies Cisco's other statement, that fynx and I read differently. On the basis of this latest link it looks like fynx was right all along. In the topology that started this there are a maximum of three bridges between end stations, so the diameter is indeed three.
Now I am going for a nice lie down in a dark room.
EB
I followed the link that iwanthome found. In there it says:
diameter of the STP domain (dia): this is the maximum number of bridges between any two points of attachment of end stations. The IEEE considers a maximum diameter of seven bridges.
I guess that this clarifies Cisco's other statement, that fynx and I read differently. On the basis of this latest link it looks like fynx was right all along. In the topology that started this there are a maximum of three bridges between end stations, so the diameter is indeed three.
Now I am going for a nice lie down in a dark room.
EB
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