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Spanning tree and trunk lines
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| na_venkatesh2 2004-11-02, 8:09 am |
| hai
I have three Layer three switches, three trunks are interconnected like ring with five four vlans running on it.when STP runs it will break the ring to prevent loop.
i want to configure switches in such a way that all the trunks are forwarding one or the other vlan and blocking some of vlans ,by doing like i will utilize the the blocked link bandwidth and also a redundant link .
is this possible?
venkat | |
| ZacDogg 2004-11-02, 12:28 pm |
| I don't know why you would do this, but you would have to adjust who is the root bridge on a per vlan basis. If you had 5 vlan's you could set the bridge priority higher for 2 vlan's on 2 switches and 1 vlan on the last switch.
Or I suppose you could tweak port costs to make traffic flow the way you wanted.
I really don't see an advantage in doing this. You are just making things much more confusing.
Zac | |
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| Its not that unusual, I've seen it on several sites and thought it was pretty much standard practice. If I remember correctly it's covered in the switching exam.
http://makeashorterlink.com/?O27C22EA9
There are other links on CCO. | |
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| First question is what trunking protocol are you running? If all the swtiches are cisco and the trunks are 802.1q, then you are probably doing PVST+. In which case adjusting the root bridge will work. You did not state where the WAN routers were (or whatever gets you out of the area, but you may want to tune HSRP also because if the default gateway is on the other side of a blocked port you will take a rather long path through the other 3 switches.
Many people do not load balance because if one thinks that you should have enough uplink capacity to carry the full traffic load without problems, then you do not care where traffic runs day to day
Since in large organizations STP is enough of an exposure out of the box, I fall in the KISS camp on that issue. | |
| na_venkatesh2 2004-11-08, 11:20 am |
| Thks for the help |
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