> On Sep 19, 2016, at 2:19 PM, Doug McIntyre <[log in to unmask]> wrote:
> On Mon, Sep 19, 2016 at 02:03:41PM -0500, Andrew Hoyos wrote:
>> What medium is the VC built on and physical topology? Just VC cables on the rear ringed through all 3?
> Yes, VC cabling in a ring, and using the VCP modules and cabling on the EX4550.
What’s the actual topology though? 4500 -> 4200 -> 4550 -> back to 4500?
>> Specific to any single 4500 destination or is it doing it to both the 4500 and the 4550?
> He wasn't aware of the EX4550, there aren't many ports lit there yet,
> he has just been testing different ports on the the EX4500.
UW Madison operates some IPerf servers you could try against too, see: https://kb.wisc.edu/uwsysnet/page.php?id=41947
They are on the 4550, it appears, so more data points to be gleaned there.
>> Check ‘show virtual-chassis vc-path source-interface <src int> destination-interface <dest int>’. Common VC port in the mix to any of the reported loss paths?
> I think in general, the VC ports run Active/Passive, so only one is
> "active" at a time going out of a box without load balancing, so only
> one (ie. vcp-1) typically shows up for all paths.
Kinda, there is a SPF calculation that happens based on src/dst interfaces. It matters which PFE of the switch the port is on (1 hop != switch, it’s actually each PFE hop). Depending on the topology here, things could be going a variety of ways.
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