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New Member

Jumbo frames increasing on the interface of NExus

Hi,

I have nexus 5000 series device and on the ethernet interface I see the jumbo frames getting increased were as I have not configured jumbo releted cmds on the device/interface.

I would like to know if the Packet which is greater that 1500 bytes going though the interface will be recorded as Jumbo frames on the interface?

<Snippet>
show interface
Ethernet5/1 is upardware: 1000/10000 Ethernet, address: 00ab.bca8.69d1 (bia 00ab.bca8.69d1)
  Description: link to seki85hubdd1
  MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA
  Port mode is trunk
  full-duplex, 10 Gb/s, media type is 1/10g
  Beacon is turned off
  Input flow-control is off, output flow-control is off
    1 minute input rate 3450 bits/sec, 6 packets/sec
  1 minute output rate 3460bits/sec, 1 packets/sec
  Rx
    34000111 input packets 11998866 unicast packets 3083 multicast packets
    3455 broadcast packets 4545678 jumbo packets 0 storm suppression packets
    1452378789 bytes
  Tx
    122345 output packets 3083 multicast packets
    21234 broadcast packets 45325 jumbo packets
    114523781 bytes
    0 input error 0 short frame 0 watchdog

Thanks in advance.

Regards

Fariha.

3 REPLIES
Bronze

Re: Jumbo frames increasing on the interface of NExus

I have the same question. We have connected a N5020 to a C6500 with etherchannel protocol LACP.

The 6500 is not configured for jumbo frames,nor is the N5020, the etherchannel is 1500 MTU and the C6500 does not show any jumbos:

6500 side:

#        sh int po11
Port-channel11 is up, line protocol is up (connected)
  Hardware is EtherChannel, address is 001f.6ca4.28e1 (bia 001f.6ca4.28e1)
  Description: PRT
  MTU 1500 bytes, BW 40000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 10Gb/s, media type is unknown
  input flow-control is on, output flow-control is off
Members in this channel: Te1/2/2 Te1/2/6 Te2/2/2 Te2/2/6
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output never, output hang never
  Last clearing of "show interface" counters 15w1d
  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  30 second input rate 6528000 bits/sec, 4571 packets/sec
  30 second output rate 5329000 bits/sec, 4568 packets/sec
     4831380565 packets input, 2423449305308 bytes, 0 no buffer
     Received 18773836 broadcasts (17913255 multicasts)
    0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected

     2051549937 packets output, 598636195990 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

On the NExus side, however, i see "received jumbo frames" increasing all the time:

#     sh int po11
port-channel11 is up
  Hardware: Port-Channel, address: 000d.ecf0.0cac (bia 000d.ecf0.0cac)
  Description: PRT
  MTU 1500 bytes, BW 40000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA
  Port mode is trunk
  full-duplex, 10 Gb/s
  Beacon is turned off
  Input flow-control is off, output flow-control is on
  Switchport monitor is off
  Members in this channel: Eth1/33, Eth1/34, Eth1/37, Eth1/38
  Last clearing of "show interface" counters never
  1 minute input rate 5373368 bits/sec, 4297 packets/sec
  1 minute output rate 6545512 bits/sec, 4282 packets/sec
  Rx
    2061916480 input packets 1868733158 unicast packets 192753119 multicast packets
    430203 broadcast packets 188338129 jumbo packets 0 storm suppression packets
    601318894954 bytes
  Tx
    4853373934 output packets 18006207 multicast packets
    865490 broadcast packets 1149313601 jumbo packets
    2430393586552 bytes
    0 input error 0 short frame 0 watchdog
    0 no buffer 0 runt 0 CRC 0 ecc
    0 overrun  0 underrun 0 ignored 0 bad etype drop
    0 bad proto drop 0 if down drop 0 input with dribble
    0 input discard
    0 output error 0 collision 0 deferred
    0 late collision 0 lost carrier 0 no carrier
    0 babble
    0 Rx pause 0 Tx pause
  1 interface resets

Is this a bug ? Or is an 1500 byte packet increased with LACP headers + trunk headers counted as a "jumbo" packet ??


Note: We are running version 4.1(3)N2(1a) on the N5020

The following features are enabled:

version 4.1(3)N2(1a)
no feature telnet
no telnet server enable
feature tacacs+
cfs eth distribute
feature udld
feature interface-vlan
feature lacp
feature fex

regards,

Geert

New Member

Re: Jumbo frames increasing on the interface of NExus

Was there any resolution to this?

We are experiencing the same problem and are on the latest code 'n5000-uk9.4.2.1.N2.1.bin'

We have Cisco 6509 VSS connected to Nexus 5020 that connect to HP Flex 10 into our ESX Chassis.

Nothing is configured for Jumbo frames (switches or ESX hosts),yet the Nexus is showing TX and RX Jumbo Frames

Ethernet1/4 is up
  Hardware: 1000/10000 Ethernet, address: 000d.eca3.470b (bia 000d.eca3.470b)
  Description: ** UKA-CH-C7000-10 - Flex 10 Bay 1 **
  MTU 1500 bytes, BW 10000000 Kbit, DLY 10 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA
  Port mode is trunk
  full-duplex, 10 Gb/s, media type is 1/10g
  Beacon is turned off
  Input flow-control is off, output flow-control is off
  Rate mode is dedicated
  Switchport monitor is off
  Last link flapped 6d03h
  Last clearing of "show interface" counters 02:31:36
  30 seconds input rate 5144832 bits/sec, 990 packets/sec
  30 seconds output rate 4222944 bits/sec, 1386 packets/sec
  Load-Interval #2: 5 minute (300 seconds)
    input rate 11.17 Mbps, 1.49 Kpps; output rate 4.11 Mbps, 1.98 Kpps
  RX
    14403129 unicast packets  39984 multicast packets  33343 broadcast packets
    14476456 input packets  11897186106 bytes
   3577133 jumbo packets  0 storm suppression packets
    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
    19810618 unicast packets  180443 multicast packets  359548 broadcast packets
    20350609 output packets  8150157037 bytes
    683596 jumbo packets
    0 output errors  0 collision  0 deferred  0 late collision
    0 lost carrier  0 no carrier  0 babble
    0 Tx pause
  0 interface resets

Anyone seen this,or have any ideas?

Regards,

Nick

New Member

Re: Jumbo frames increasing on the interface of NExus

We have this with version n5000-uk9.4.1.3.N2.1a.bin. We have the same setup as you - uplinked to a VSS core using HP 785s on ESX 4.

I first saw this when troubleshooting an issue that turned out to be a VMWare Vsphere kernel and NIC driver issue on the server-side. Whether this is a bug similar to the old oversize frame counter issue on Catalysts, or some device in our network is using jumbo frames, I don't know. I spoke with TAC on this and the engineer I got didn't know either. Regardless, we see no negative affects. Do you? What problems are you seeing? If it is similar to the problems we had, I might be able to point you in the right direction.In conclusion, it was all VMWare and HP.

Darren

2017
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