On Sep 19, 2016, at 2:19 PM, Doug McIntyre <merlyn@iphouse.net> 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. -- Andrew Hoyos hoyosa@gmail.com