port has faulty link

[amelamel]

Hi,
i have cisco 2960-X used to connect a monitoring system (monitors and the central unit) the ports that are connected to the monitors are in faulty link status after showing one of those interfaces "show interface gi 2/0/2" it reveals that there is collisions, input errors, CRC ,runts and multicast

GigabitEthernet2/0/2 is up, line protocol is up (connected)
Hardware is Gigabit Ethernet, address is 009a.d293.1c82 (bia 009a.d293.1c82)
MTU 1500 bytes, BW 10000 Kbit/sec, DLY 1000 usec,
reliability 253/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Half-duplex, 10Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output 00:00:01, 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 53000 bits/sec, 9 packets/sec
5 minute output rate 5000 bits/sec, 5 packets/sec
2933082 packets input, 1712065203 bytes, 0 no buffer
Received 489019 broadcasts (0 multicasts)
17537 runts, 0 giants, 0 throttles
17810 input errors, 1 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
11849928 packets output, 1355358369 bytes, 0 underruns
0 output errors, 10287 collisions, 13 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
i searcherd about this and i found that may be the size of the packets is too big to be handeled by the link
please help me with this.
amel

 

[iggsterman]

It is duplex mismatch. look at the line that says:

 Half-duplex, 10Mb/s, media type is 10/100/1000BaseTX

This could mean that the the ports have mismatching config for the link, or the cable is bad.

 

[ADB100]

By default all copper Ethernet ports on a Catalyst 2960X are set to auto-negotiate 10/100/1000Mbps and half/full duplex as well as Auto-MDIX to cater for connecting to another switch or DCE presented device.
Speed is negotiated first - 10Mbps & 100Mbps using the same two cable pairs but using a different frequency, 1000Mbps uses all four pairs so is negotiated differently and also only supports full-duplex operation (sort of...). If the two devices agree on either 10Mbps or 100Mbps they then try and negotiate the duplex using something called FLP - Fast Link Pulse. If they don't detect the other side doing the same thing they fallback to half duplex which is what the standard dictates (IBM N-Ways look it up). Half-duplex will always result in errors as only one side can transmit at once.
You can usually disable auto-negotiation and force a speed and duplex, however this MUST be done on both sides of the link or you WILL get a mismatch. Refer to this table:

https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/17053-46.html

Based on 10Mbps half-duplex the switch is attached to a device that is either forced at 10Mbps speed and forced either full or half duplex or its a dumb device like a hub.