Hello,
Trying to understand the root cause behind an incrementing amount of Rcv-Errs on SFP ports that have no SFP Module or a connection. I should state, the switches that are experiencing this behavior are in a stack of at least 3. I've seen this occur on a WC-C3850-48P Gigabit SFP port as well as a 9300-48U TenGig SFP Port. Each time its a port that has no SFP module at all with generally no configuration.
Below is one such port and the presented errors:
!
interface TenGigabitEthernet2/1/7
end
!
TenGigabitEthernet2/1/7 is down, line protocol is down (notconnect)
Hardware is Ten Gigabit Ethernet, address is redacted (bia redacted)
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 not set
Auto-duplex, Auto-speed, link type is auto, media type is unknown
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 711932690 bytes, 0 no buffer
Received 0 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
708413 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
0 packets output, 0 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 pause output
0 output buffer failures, 0 output buffers swapped out
!
show interfaces tenGigabitEthernet 2/1/7 counters errors
Port Align-Err FCS-Err Xmit-Err Rcv-Err UnderSize OutDiscards
Te2/1/7 0 0 0 708382 0 0
In each situation, this seems to occur on one of the N+1 "Member" role switches in the stack (480Gbps C9300 stack). Could the stack itself in some way be a cause of this? They increment about 10-30 input errors every 5-10 seconds on average.
