I am seeing a problem with new N4032F and N2048 switches and jumbo frames. Things appear to be working, but the statistics show packets being dropped. For example:
show interfaces counters tengigabitethernet 1/0/5
Port InTotalPkts InUcastPkts InMcastPkts InBcastPkts
--------- ---------------- ---------------- ---------------- ----------------
Te1/0/5 2914419918 2914262020 58 157840
Port OutTotalPkts OutUcastPkts OutMcastPkts OutBcastPkts
--------- ---------------- ---------------- ---------------- ----------------
Te1/0/5 3585251489 3553257957 16903382 15090150
FCS Errors: ................................... 0
Single Collision Frames: ...................... 0
Late Collisions: .............................. 0
Excessive Collisions: ......................... 0
Multiple Collisions: .......................... 0
Received packets dropped > MTU: ............... 425952374
Transmitted packets dropped > MTU: ............ 211808792
Internal MAC Rx Errors: ....................... 0
Received Pause Frames: ........................ 37536
Transmitted Pause Frames: ..................... 0
Receive Packets Discarded: .................... 21
Transmit Packets Discarded: ................... 38475257
Received PFC Frames: .......................... 0
Transmitted PFC Frames: ....................... 0
console#show system mtu
System jumbo MTU size is 9216 bytes
The configuration does include:
system jumbo mtu 9216
We have several Vmware ESXi hosts configured for 9000 MTU, and MD3220i with the MTU set for 9000 (and vlan tagged all ports in question).
Here is our version info:
console#show version
Machine Description............... Dell Networking Switch
System Model ID................... N4032F
Machine Type...................... Dell Networking N4032F
Serial Number..................... CN05KGDH282984470025A00
Manufacturer...................... 0xbc00
Burned In MAC Address............. F8B1.5636.E046
System Object ID.................. 1.3.6.1.4.1.674.10895.3044
CPU Version....................... XLP308H-B2
SOC Version....................... BCM56842_A1
HW Version........................ 3
CPLD Version...................... 17
unit active backup current-active next-active
---- ----------- ----------- -------------- --------------
1 6.1.0.1 6.0.0.8 6.1.0.1 6.1.0.1
(The 2048 is also running 6.1.0.1)
Any ideas why the switch is reporting dropped packets? Is it just a bug on the counters, or are they actually being dropped?
Thanks,
John
PS: This shows a breakdown on different size packets:
console#show statistics tengigabitethernet 1/0/5
Total Packets Received (Octets)................ 1098152047898
Packets Received 64 Octets..................... 37536
Packets Received 65-127 Octets................. 1387863561
Packets Received 128-255 Octets................ 417995386
Packets Received 256-511 Octets................ 593761779
Packets Received 512-1023 Octets............... 66923691
Packets Received 1024-1518 Octets.............. 23713526
Packets Received > 1518 Octets................. 426111463
Packets RX and TX 64 Octets.................... 701251
Packets RX and TX 65-127 Octets................ 3225823472
Packets RX and TX 128-255 Octets............... 900048265
Packets RX and TX 256-511 Octets............... 931452081
Packets RX and TX 512-1023 Octets.............. 236045021
Packets RX and TX 1024-1518 Octets............. 571934636
Packets RX and TX 1519-2047 Octets............. 3089
Packets RX and TX 2048-4095 Octets............. 10130
Packets RX and TX 4096-9216 Octets............. 45523
Total Packets Received Without Errors.......... 2916369418
Unicast Packets Received....................... 2916211515
Multicast Packets Received..................... 58
Broadcast Packets Received..................... 157845
Receive Packets Discarded...................... 21
Total Packets Received with MAC Errors......... 0
Jabbers Received............................... 0
Fragments/Undersize Received................... 0
Alignment Errors............................... 0
FCS Errors..................................... 0
Overruns....................................... 0
Total Received Packets Not Forwarded........... 37557
802.3x Pause Frames Received................... 37536
Unacceptable Frame Type........................ 21
Total Packets Transmitted (Octets)............. 1573471772584
Packets Transmitted 64 Octets.................. 663715
Packets Transmitted 65-127 Octets.............. 1837959911
Packets Transmitted 128-255 Octets............. 482052879
Packets Transmitted 256-511 Octets............. 337690302
Packets Transmitted 512-1023 Octets............ 169121330
Packets Transmitted 1024-1518 Octets........... 548221110
Packets Transmitted > 1518 Octets.............. 211957517
Max Frame Size................................. 9216
Total Packets Transmitted Successfully......... 3587725506
Unicast Packets Transmitted.................... 3555702876
Multicast Packets Transmitted.................. 16918888
Broadcast Packets Transmitted.................. 15103742
Transmit Packets Discarded..................... 38475257
Total Transmit Errors.......................... 0
Total Transmit Packets Discarded............... 38475257
Single Collision Frames........................ 0
Multiple Collision Frames...................... 0
Excessive Collision Frames..................... 0
802.3x Pause Frames Transmitted................ 0
GVRP PDUs received............................. 0
GVRP PDUs Transmitted.......................... 0
GVRP Failed Registrations...................... 0
GMRP PDUs Received............................. 0
GMRP PDUs Transmitted.......................... 0
GMRP Failed Registrations...................... 0
BPDU: sent 555130, received 0
EAPOL Frames Transmitted....................... 0
EAPOL Start Frames Received.................... 0
Time since counters last cleared............... 16 day 19 hr 58 min 40 sec