mikey250
asked on
UDLD QUERY
Hi Ive setup a 3 switch Triange as follows:
Switch A - Vtp server root 4096
Port 1 connected to Switch B port 1
Port 12 connected to Switch C port 12
Port 11 connected to Switch C port 11
Switch B - Vtp server secondary root 8192
Port 1 connected to Switch A port 1
Port 10 connected to Switch C port 10
Switch C - Access switch 32768
Port 10 connected to Switch B port 10
Port 11 connected to Switch A port 11
Port 12 connected to Switch A port 12
Uplinkfast has been added on Switch C
Which ports do I enable 'udld', although I think they specifically go on: Switch A ports 1 & 11 & 12, Switch B port 1 & Switch C port 12 - ?
Switch A - Vtp server root 4096
Port 1 connected to Switch B port 1
Port 12 connected to Switch C port 12
Port 11 connected to Switch C port 11
Switch B - Vtp server secondary root 8192
Port 1 connected to Switch A port 1
Port 10 connected to Switch C port 10
Switch C - Access switch 32768
Port 10 connected to Switch B port 10
Port 11 connected to Switch A port 11
Port 12 connected to Switch A port 12
Uplinkfast has been added on Switch C
Which ports do I enable 'udld', although I think they specifically go on: Switch A ports 1 & 11 & 12, Switch B port 1 & Switch C port 12 - ?
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Ok... Ive selected 'Aggressive as it tries to re-establish upto 8 attempts, instead of Normal mode', although not sure in what scenario I should choose..?
Qns1. Is there any form of software or something out their that can cause me to simulate this as in my mind if 1 cable is connecting 2 switches and one end has a faulty pin cable inside the rj45 connection then Im assuming 'udld' switches from blocking to forwarding - ?
Qns2. If it does switch to forwarding does the traffic follow a different direction or use another pin cable inside the fault rj45, as cant get my head around that as also thinking about full duplex.. ?
Once those are answered above I think that is it for 'UDLD'..:)
Qns1. Is there any form of software or something out their that can cause me to simulate this as in my mind if 1 cable is connecting 2 switches and one end has a faulty pin cable inside the rj45 connection then Im assuming 'udld' switches from blocking to forwarding - ?
Qns2. If it does switch to forwarding does the traffic follow a different direction or use another pin cable inside the fault rj45, as cant get my head around that as also thinking about full duplex.. ?
Once those are answered above I think that is it for 'UDLD'..:)
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ASKER
I have real switches..GNS3 - Oh ok did not know that..!
Qns1. Ok as per my main thread my 3 switch triangle with 2 VTP servers and 1 access switch. Ive also added 'uplinkfast' on Switch C for port 11 so if the main traffic route is faulty then 'uplinkfast' will start, sending traffic in the 'opposite' direction..!?
Qns2. Are you saying that for eg between both Vtp Servers A & B, I could also add a secondary cable between them both so 'udld' would 'disable one cable and switch to the secondary cable keeping traffic flow in same direction - ?
Qns3. I suppose both 'Qns 1 & 2' can be used at same time or maybe some equipment may or may not have both features so they are just to different ways of keeping backup, but I would if 'udld' could work with 'HSRP' - ?
I think these last 3 questions above should do it...:)
Qns1. Ok as per my main thread my 3 switch triangle with 2 VTP servers and 1 access switch. Ive also added 'uplinkfast' on Switch C for port 11 so if the main traffic route is faulty then 'uplinkfast' will start, sending traffic in the 'opposite' direction..!?
Qns2. Are you saying that for eg between both Vtp Servers A & B, I could also add a secondary cable between them both so 'udld' would 'disable one cable and switch to the secondary cable keeping traffic flow in same direction - ?
Qns3. I suppose both 'Qns 1 & 2' can be used at same time or maybe some equipment may or may not have both features so they are just to different ways of keeping backup, but I would if 'udld' could work with 'HSRP' - ?
I think these last 3 questions above should do it...:)
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ASKER
These STP modes are confusing.....!!!! Ive already set both 'udld & uplinkfast' on all my switches - 'spanning-tree mode pvst anyway..!!
Qns1. My switches by default has - 'spanning-tree mode pvst', which I think is the 'standard STP', so presumably I should change to 'spanning-tree mode rapid-pvst' - ?
Qns2. I understand that if I use 'UDLD' then I dont really need 'uplinkfast', as traffic can stay in same flow direction..Im assuming it is faster convergence than 'uplinkfast' - ?
Qns1. My switches by default has - 'spanning-tree mode pvst', which I think is the 'standard STP', so presumably I should change to 'spanning-tree mode rapid-pvst' - ?
Qns2. I understand that if I use 'UDLD' then I dont really need 'uplinkfast', as traffic can stay in same flow direction..Im assuming it is faster convergence than 'uplinkfast' - ?
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Apologies..!! I think thats it now for this.. appreciated.. Im gonna read some more on this now as I think I get it..!!thanks for being patient..:)
No problem.
ASKER
Hi There was one question I asked earlier but you never replied to that one at: 37064232, as below:
Qns1. Ok... Ive selected 'Aggressive as it tries to re-establish upto 8 attempts, instead of Normal mode', although not sure in what scenario I should choose..?
Qns1. Ok... Ive selected 'Aggressive as it tries to re-establish upto 8 attempts, instead of Normal mode', although not sure in what scenario I should choose..?
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Hi, is that it..okay!!:)
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Hi don, yes I can appreciate that.!!
ASKER
Although the question was answered first time with Soulja, I feel the other responses to some of my extra questioning around STP was pertinent and gave more breadth to the answer that assisted in proper understanding..Expert Don also gave clarity with the response..All appreciated!!
Could this be any more clear?
UDLD, has nothing to do with uplink fast or spanning tree. It works hand in hand with spanning tree, it's not a substitution.
UDLD, has nothing to do with uplink fast or spanning tree. It works hand in hand with spanning tree, it's not a substitution.
ASKER
Hi Soulja, apologies if Ive annoyed you some and yes I can see your comments at:37065230 as assumed that if another Expert comments on same thread that they would get some partial points...In this case how do I re-allocate who points to you?
No Biggie, just wanted to point out that I had already stated that UDLD had nothing to do with spanning tree.
ASKER