Jumbo frames increasing on the interface of NExus

fariha zain · ‎01-14-2010

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.

gnijs · ‎06-17-2010

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

vermin · ‎09-24-2010

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

Darren Strunk · ‎09-24-2010

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