Switching

I have a network with about 60 EX3200 switches that control cell sites.  We encounter a network loop when we connect a certain fiber hub and into a ring (basically a ring of 10 sites wireless microwaved together with fiber at the top and bottom for redundancy.  I was under the assumption that RSTP would fix this on its own - not exactly working that way though with this fiber hub.

 

I am not a network engineer so CLI is a challenge.  I like the JUNOS GUI and it seems to do all the functions CLI junkies (99.9% of this forum) seem to prefer in GUI.

 

I would like to know how to set up RSTP at the POP - or should I set parameters at each fiber hub?  There doesn't seem to be any good info about RSTP configurations within the EX Series on the web.

 

Also, I was told there needs to be some sort of "root" configuration at the POP - cannot find any information about this but maybe its because this is too remedial to mention.

 

Any guidance (in laymans terms please) is very much appreciated!

I believe RSTP is enabled by default - at least it has been since the ~9.5 Junos days.  What version of code are your switches running?

 

 

Without knowing the full topology, I suspect RSTP may be enabled, however the root bridge may not be set properly such that the hub site(s) are blocking links vs edge sites blocking links.

 

all switches I believe have a default priority of 32k, and it iirc comes down to the switch Mac address as to which is the root bridge.  If you set one switch's root bridge to 4k it will become the root bridge, and spanning tree will re-calculate the loop-free topology.

 

Will

Hi Will, Thank you for the response - you confirmed some of my thoughts based on my research. I am running the latest version. Can you please help me with the commands I should input at the core? Also, I cannot find any information regarding enabling flow control. Is that an option I can enable someplace? Thank you!

please share your topology...along with below commands o/p from core switches.

 

show spaning-tree bridge

show spaning-tree interfaces

 

Collect above commands o/p  also when you change the physical topology to build ring and redundant topology.

 

Share your further observations on this case if any.?

 

Flow control is by default disabled as per my knowledge.

 

use set interfaces ge-0/0/0 ether-options flow-control

 

Accept the solutoin if this answers your query.