I don't mean to Triple Post, but I've found what appears to be the cause. Root still to be determined by the server Admin.   With noticing traffic failing on the link between my c9500 and the m6220, I looked into the counters and saw  the TX pause frames: BldChs1A2#show interfaces counters te1/1/1 Port InTotalPkts InUcastPkts InMcastPkts InBcastPkts--------- ---------------- ---------------- ---------------- ----------------Te1/1/1 1128521 18698 375403 734420 Port OutTotalPkts OutUcastPkts OutMcastPkts OutBcastPkts--------- ---------------- ---------------- ---------------- ----------------Te1/1/1 9363 1208 7828 327 FCS Errors: ................................... 0Single Collision Frames: ...................... 0Late Collisions: .............................. 0Excessive Collisions: ......................... 0Multiple Collisions: .......................... 0Received Oversize Packets: .................... 0Transmitted Oversize Packets: ................. 0Internal MAC Rx Errors: ....................... 0Received Pause Frames: ........................ 0Transmitted Pause Frames: ..................... 13641269Receive Packets Discarded: .................... 32Transmit Packets Discarded: ................... 0     I then checked all my interface counters on the m6220, to see if there was excessive traffic coming from any of it's active interfaces (Only blade 9 was supposed to have any vnic's attached to a2). BldChs1A2#show interfaces counters Port InTotalPkts InUcastPkts InMcastPkts InBcastPkts--------- ---------------- ---------------- ---------------- ----------------Gi1/0/1 0 0 0 0Gi1/0/2 0 0 0 0Gi1/0/3 108 0 108 0Gi1/0/4 3775806 0 3775806 0Gi1/0/5 0 0 0 0Gi1/0/6 0 0 0 0Gi1/0/7 0 0 0 0Gi1/0/8 0 0 0 0Gi1/0/9 637 224 113 300Gi1/0/10 0 0 0 0Gi1/0/11 86 0 20 66Gi1/0/12 0 0 0 0Gi1/0/13 0 0 0 0Gi1/0/14 0 0 0 0Gi1/0/15 0 0 0 0Gi1/0/16 0 0 0 0Gi1/0/17 0 0 0 0Gi1/0/18 0 0 0 0Gi1/0/19 0 0 0 0Gi1/0/20 0 0 0 0 Te1/1/1 1134693 18753 377354 738586Te1/1/2 0 0 0 0   Gi1/0/9 was supposed to have traffic, as well as TE 1/1/1. Gi1/0/11 as low, and negligible, but Gi1/0/4 stuck out.   I shut down interface gi1/0/4, and immediately  the pause frames stopped. I was then able to reach the m6220 from my c9500, as well as reach all my test VMs.   We're currently checking out what on blade 4 would be causing this kind of traffic that caused the pause frames. It's al older 610 half height blade, but vcenter doesn't show any NIC's that would appear on the A2 switch (vmnic1). We might just decommission this blade, but I'd like to find the actual cause first. For now, it appears the issue is resolved.
Enivornment: m1000e with m6220 switches in the A1/A2. Blades are M630 our ESXI hosts are teamed between A1 and A2. A1 and A2 are not stacked. The interfaces for vmnic0(a1) and vmnic1(a2) on the m6220 are configured the same. Right now, all the blades function when only assigned to vmnic0(a1), however traffic stops when we add in vmnic1(a2) as a redundant link. if we just use vmnic1 and remove vmnic0, they also do not send traffic. Running show interface counters gi1/0/9, i'm seeing minimal traffic, with all traffic being discarded on transmit.   Port InTotalPkts InUcastPkts InMcastPkts InBcastPkts--------- ---------------- ---------------- ---------------- ----------------Gi1/0/9 2685 434 58 2193 Port OutTotalPkts OutUcastPkts OutMcastPkts OutBcastPkts--------- ---------------- ---------------- ---------------- ----------------Gi1/0/9 158902 2380 48510 108012 FCS Errors: ................................... 0Single Collision Frames: ...................... 0Late Collisions: .............................. 0Excessive Collisions: ......................... 0Multiple Collisions: .......................... 0Received Oversize Packets: .................... 0Transmitted Oversize Packets: ................. 0Internal MAC Rx Errors: ....................... 0Received Pause Frames: ........................ 0Transmitted Pause Frames: ..................... 0Receive Packets Discarded: .................... 0Transmit Packets Discarded: ................... 559886 I'm having trouble identifying if there is a configuration issue on the ESXI host, or the m1000e, or if there is a hardware failure. Everything was working fine until some weeks ago. The server admin noted that no changes were made on his end in ESXI or in the dell CMC, and no configuration changes were made on the switches. The A2 switch shows as connected, and no errors in the Dell CMC for it. CDP is successful over the link between the A2 and the blades. I'm trying to find out why the transmits are all being discarded. Any help is appreciated
m1000e no traffic between A2 and blades with esxi