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Occasional Visitor
Posts: 1
Registered: ‎02-05-2019

I have a Brocade ICX 7450-48F with a 1G connection to my Cisco 3560 but the trunk is flapping

Good morning,

 

The facts:

I have a Brocade ICX 7450-48F switch that is being used as my Distribution Switch for my small network. It has a single 1G connection to a Cisco 3560 via single mode fiber.

 

The ICX is configured with 

Port-name

Dual-mode X

 

The Cisco device is configured with

trunk encapsulation dot1q

switchport trunk native vlan (X to match the ICX)

switchport trunk allowed vlan 1 - X

switchport mode trunk

switchport nonegotiate

mls and qos configurations

 

The Issue: The ICX connection to the Cisco device is flapping, meaning I am losing connection to the downstream Cisco device. A Show Log reveals that interface e 1/1/3 is receiving STP State messages for each of my configured VLANS, meaning that each VLAN in the log is cycling through its Listen Learn Forward State 

for example : 

VLAN X Port 1/1/3 STP State -> Listening (MakeFwding)

VLAN X Port 1/1/3 STP State -> Learning (FwDlyExpiry)

VLAN X Port 1/1/3 STP State -> Forwarding (FwDlyExpiry)

 

I don't understand why STP is frequently updating itself causing the interface to bounce. Could this be avoided if I add a second 1G trunk between the ICX and Cisco device?

Community Manager
Posts: 297
Registered: ‎03-03-2014

Re: I have a Brocade ICX 7450-48F with a 1G connection to my Cisco 3560 but the trunk is flapping

[ Edited ]

@Tenmujin 

 

ICX Switch line was acquired by Ruckus, please post your question on the Ruckus Community

for immediate assistance.

 

Thank you

 

Jason

Community Manager

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