input errors and giants on 4507 TenGigabitEthernet interface

[BorislavPenchev0962]

Hi,

we have the error for some time now on TenGigabitEthernet5/7; there are no other modules in the switch hence we can try only with WS-X4712-SFP+E;

now we tried to move connection to TenGigabitEthernet 5/12 and error replicated; we did replaced a cable and SFP 10GBase-LR, but issue is the same:

GOGO#sh int te 5/12
TenGigabitEthernet5/12 is up, line protocol is up (connected)
  Internet address is 192.192.192.46/30
  MTU 1500 bytes, BW 10000000 Kbit/sec, 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, link type is auto, media type is 10GBase-LR
  input flow-control is on, output flow-control is on
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output never, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 11000 bits/sec, 6 packets/sec
  5 minute output rate 3013000 bits/sec, 2229 packets/sec
  L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  IPv6 L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  IPv6 L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
     104481 packets input, 40655974 bytes, 0 no buffer
     Received 2302 broadcasts (0 IP multicasts)
 --->  0 runts, 3540 giants, 0 throttles
  ---> 3540 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 input packets with dribble condition detected
     13766955 packets output, 3279702819 bytes, 0 underruns
     0 output errors, 0 collisions, 4 interface resets
     0 unknown protocol drops
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

 

GOGO#sh int te 5/12 summary

*: interface is up
IHQ: pkts in input hold queue     IQD: pkts dropped from input queue
OHQ: pkts in output hold queue    OQD: pkts dropped from output queue
RXBS: rx rate (bits/sec)          RXPS: rx rate (pkts/sec)
TXBS: tx rate (bits/sec)          TXPS: tx rate (pkts/sec)
TRTL: throttle count

  Interface                   IHQ       IQD       OHQ       OQD      RXBS      RXPS      TXBS      TXPS      TRTL
-----------------------------------------------------------------------------------------------------------------
* Te5/12                        0         0         0         0     11000         6   2922000      2181         0

 may you advise what we can change or how to proceed ?

thanks

[BorislavPenchev0962]

here the output from Interface TenGigabitEthernet5/7:

#sh int te 5/7
TenGigabitEthernet5/7 is up, line protocol is up (connected)
Internet address is 192.192.192.46/30
MTU 1500 bytes, BW 10000000 Kbit/sec, 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, link type is auto, media type is 10GBase-LR
input flow-control is on, output flow-control is on
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 5130000 bits/sec, 604 packets/sec
5 minute output rate 2056000 bits/sec, 1060 packets/sec
L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
IPv6 L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
IPv6 L3 out Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
120890184236 packets input, 104395934121557 bytes, 0 no buffer
Received 10703265 broadcasts (0 IP multicasts)
0 runts, 
-> 14261806 giants, 0 throttles
-> 14261806 input errors, 0 CRC, 0 frame, 1380 overrun, 0 ignored
0 input packets with dribble condition detected
53995611062 packets output, 16765841172297 bytes, 0 underruns
0 output errors, 0 collisions, 3 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

[marce1000]

 - FYI : https://bst.cloudapps.cisco.com/bugsearch/bug/CSCus15382

 M.

[BorislavPenchev0962]

our switch is WS-C4507R+E, module is WS-X45-SUP8L-E and IOS 03.11.03a , its different from this bug

[MHM Cisco World]

config the interface with MTU 1520 and check again.

[BorislavPenchev0962]

MTU should be configured on both side interfaces and there will connection interruption ?

[BorislavPenchev0962]

we did configured the MTU 1520 on both opposite interfaces - input errors are continue to increment. should we raise it ?

[MHM Cisco World]

Switch# show interfaces fa3/5 capabilities

check what is max. MTU giants  

[BorislavPenchev0962]

#show interfaces TenGigabitEthernet5/7 capabilities
TenGigabitEthernet5/7
  Model:                 WS-X4712-SFP+E-Gbic
  Type:                  10GBase-LR
  Speed:                 1000,10000
  Duplex:                full
  Auto-MDIX:             no
  EEE:                   no
  Trunk encap. type:     802.1Q
  Trunk mode:            on,off,desirable,nonegotiate
  Channel:               yes
  Broadcast suppression: percentage(0-100), hw
  Multicast suppression: percentage(0-100), hw
  Flowcontrol:           rx-(off,on,desired),tx-(off,on,desired)
  VLAN Membership:       static, dynamic
  Fast Start:            yes
  CoS rewrite:           yes
  Maximum MTU:           9198 bytes (Jumbo Frames)
  Multiple Media Types:  no
  Diagnostic Monitoring: yes

[BorislavPenchev0962]

is it possible that we hit this:

- 4500 series has known limitation: Packets that are larger than 1522 bytes count as oversize, or "giants". These giants also show up as input errors. ISL packets can have a maximum size of 1548 bytes. Packets between 1522 and 1548 bytes switch correctly, but still count as giants because of a known limitation ?

[EdgarMurray8920]

I have seen configurations on Catalyst 4506E with the MTU of 9198 which I think is the maximum. There is more information about baby giant and MTU on the following link https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/53SG/configuration/config/sw_int.html

[BorislavPenchev0962 · Accepted solution]

fyi

Since the offending packets size is 1538 bytes, I have tested in our internal lab and since we have a layer 3 port we can increase the IP MTU value but this value depends on the MTU value it self configured under the port, so you can test applying the below but please test it in a maintenance window to avoid any issues and you can increase the value higher if you still notice counter increasing:

SW1(config-if)#mtu 1550
SW1(config-if)#ip mtu 1550
SW1(config-if)#end
SW1#

error no longer appeared