大量巨帧 Too many jumbo packets on N9K

[stephen.han]

hi，

N9K设备，接VMware主机的接口流量不大，但是巨帧比例很大，这种情况大家是怎么处理，有没有一些官方的参考，谢谢。

Ethernet1/8 is up
admin state is up, Dedicated Interface
Hardware: 100/1000 Ethernet, address: e41f.7b1f.15af (bia e41f.7b1f.15af)
MTU 1500 bytes, BW 1000000 Kbit , DLY 10 usec
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, medium is broadcast
Port mode is trunk
full-duplex, 1000 Mb/s
Beacon is turned off
Auto-Negotiation is turned on FEC mode is Auto
Input flow-control is off, output flow-control is off
Auto-mdix is turned on
Switchport monitor is off
EtherType is 0x8100
EEE (efficient-ethernet) : n/a
admin fec state is auto, oper fec state is off
Last link flapped 41week(s) 2day(s)
Last clearing of "show interface" counters 6d17h
0 interface resets
Load-Interval #1: 30 seconds
30 seconds input rate 1152888 bits/sec, 437 packets/sec
30 seconds output rate 1757128 bits/sec, 599 packets/sec
input rate 1.15 Mbps, 437 pps; output rate 1.76 Mbps, 599 pps
Load-Interval #2: 5 minute (300 seconds)
300 seconds input rate 1028720 bits/sec, 356 packets/sec
300 seconds output rate 1658456 bits/sec, 507 packets/sec
input rate 1.03 Mbps, 356 pps; output rate 1.66 Mbps, 507 pps
RX
259899234 unicast packets 228086 multicast packets 426641 broadcast packets
260553961 input packets 88634203284 bytes
24966168 jumbo packets 0 storm suppression bytes
0 runts 0 giants 0 CRC 0 no buffer
0 input error 0 short frame 0 overrun 0 underrun 0 ignored
0 watchdog 0 bad etype drop 0 bad proto drop 0 if down drop
0 input with dribble 0 input discard
0 Rx pause
TX
315626184 unicast packets 9146675 multicast packets 34442673 broadcast packets
359215532 output packets 140009434513 bytes
60664517 jumbo packets
0 output error 0 collision 0 deferred 0 late collision
0 lost carrier 0 no carrier 0 babble 0 output discard
0 Tx pause

[wyc_chao]

n9k 的MTU是可以调的

conf t

int x/x

mtu 9216

[huoran1234]

改下接口的MTU就好，现在巨帧很正常

[Rps-Cheers · Accepted solution]

Per-Port MTU Configuration

Nexus 3000: Includes Nexus 3132Q-V, 3164, 31108, 31128PQ, 3200 Series, and 36180YC-R switches

Neuxs 7000: All Nexus 7000- and 7700 Series switches

Nexus 9000: All Nexus 9200 Series switches (includes 92xxx), 9300 Series switches (includes 93xxx), and 9500 Series switches

In order to configure MTU on a per-port basis, this configuration is needed:

Nexus(config)#interface ethernet 1/1
Nexus(config-if)#mtu 9216

https://www.cisco.com/c/en/us/support/docs/switches/nexus-9000-series-switches/118994-config-nexus-00.html