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i have one switch and two ports for two dirrent network they is ring both port in same vlan configuration, i want solution if one port down then autometic traafic gone from 2nd port it is possible?

kish05
Level 1
Level 1

 i have one switch and two ports for two dirrent network they is ring both port in same vlan configuration, i want solution if one port down then autometic traafic gone from 2nd port it is possible?

 

Note: switch1 in  2 ethernet port avaibale only 21-22

 

switch1 ethernet port 21 is connect with switch2 ethernet port 4 other port is full

switch1 ethernet port 22 is connect with switch3 ethernet port 1 other port is full

 

switch2 in ethernet port 5 is connect with  switch3 in ethernet port 2. other port is full

 

ring network so if switch1 i port 21 down then autometic traafic gone from switch port 22 it is possible?

 

kindly check attechment

7 Replies 7

 

Yes, it is possible. Since the switches are connected in ring (in a loop), you need to run spanning-tree protocol (STP) to avoid the network loop. STP will block one of the interfaces on Switch 1. When the forwarding interface is down, the other interface which was blocking will become forwarding and will pass traffic.

 

In case if you are not familiar with STP, please look here:-  https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/5234-5.html

 

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HTH,

Meheretab 

HTH,
Meheretab

any other idea for same issue? native vlan  and extra???


@kish05 wrote:

any other idea for same issue? native vlan  and extra???


use different post to give more information about your setup. if this is same issue and same topology network, look at the suggestions.

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Native VLAN:- If a switch receives untagged frames on a trunk port with dot1q encapsulation, the frames are assumed to be part of the Native Vlan. So, it is designed to allow forwarding untagged frames in trunk ports when you use dot1q encapsulation. It is not designed to avoid loops. 

 

 

Please do not forget to rate helpful replies and to accept correct answers.

 

HTH,
Meheretab

HTH,
Meheretab

it is possible without stp use ?if any other solution?

if you do not required Layer2, then configure L3 interface this avold loops, make sure you setup routing path correctly, so the traffic can be reached destination if one of the link fails. here i prefer to have IGP running if you can.

 

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balaji.bandi
Hall of Fame
Hall of Fame

Adding to other post, STP blocks if find the loops, if you can make STP priority setup and malke links and prune the vlan required only.

 

 

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