Connectivity Guide

Table Of Contents
Discard Counters
The Dell Networking OS discard counters counts the packets or frames which are legitimate but dropped due to lack of
operation of the higher layer protocol. The discard counters do not count the errors such as runts, giants, throttles, CRC,
overrun, underrun, symbol error, etc.
For example, when an OSPF packet is received on a switch which has OSPF disabled, the packet gets dropped due to filter
processor (FP) entry and the discard counter gets incremented. However, the packets that are forwarded to the CPU are
dropped at the interface level and a copy of the packet is forwarded to the CPU. Therefore, the discard counter is increased
when a packet matches an FP entry, irrespective of the action defined in the FP entry to avoid pipeline processing in the
hardware.
Display discard counters
View the discard counters.
EXEC Privilege Mode
show interfaces
DellEMC# show interfaces tengigabitethernet 1/1
TenGigabitEthernet 1/1 is up, line protocol is down
Hardware is DellEMCEth, address is 00:01:e8:41:77:95
Current address is 00:01:e8:41:77:95
Pluggable media present, SFP type is 1000BASE-SX
Wavelength is 850nm
Interface index is 100974648
Port will not be disabled on partial SFM failure
Internet address is not set
MTU 1554 bytes, IP MTU 1500 bytes
LineSpeed 1000 Mbit
Flowcontrol rx on tx on
ARP type: ARPA, ARP Timeout 04:00:00
Last clearing of "show interface" counters 1w0d5h
Queueing strategy: fifo
Input Statistics:
0 packets, 0 bytes
0 Vlans
0 64-byte pkts, 0 over 64-byte pkts, 0 over 127-byte pkts
0 over 255-byte pkts, 0 over 511-byte pkts, 0 over 1023-byte pkts
0 Multicasts, 0 Broadcasts
0 runts, 0 giants, 0 throttles
0 CRC, 0 overrun, 0 discarded
Output Statistics:
0 packets, 0 bytes, 0 underruns
0 64-byte pkts, 0 over 64-byte pkts, 0 over 127-byte pkts
0 over 255-byte pkts, 0 over 511-byte pkts, 0 over 1023-byte pkts
0 Multicasts, 0 Broadcasts, 0 Unicasts
0 Vlans, 0 throttles, 0 discarded, 0 collisions, 0 wreddrops
Rate info (interval 299 seconds):
Input 00.00 Mbits/sec, 0 packets/sec, 0.00% of line-rate
Output 00.00 Mbits/sec, 0 packets/sec,0.00% of line-rate
Time since last interface status change: 1w0d5h
DellEMC#
Points to remember:
1. Following are some of the major protocols that can be dropped based on the FP rule entry, if those protocols are not
configured or blocked. All these drops are accounted as discard counters.
LLDP BPDU redirects
ARP
STP/RSTP BPDU redirects
BGP
OSPF
ECMP and LAG show cases
VLT LLDP PDUs
VLT DOT1x PDUs
Interfaces
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