troubleshooting interface Flapping

[ottavio]

hi,

i have a port on firewall fortinet which is flapping:

monitor: Interface port5 was turned up 2012-02-28 10:30:39 information interface-stat-change Link monitor: Interface port5 was turned down 2012-02-28 10:30:38 information interface-stat-change Link


on the connected switch:



SW-4506-B#show interface GigabitEthernet 5/29
GigabitEthernet5/29 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet Port, address is 02c8.d8cb.577d (bia 02c8.d8cb.577d)
Description: ITBACSPFW06 p5
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed, link type is auto, media type is 10/100/1000-TX
input flow-control is off, output flow-control is off
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
55742 packets input, 63690596 bytes, 0 no buffer
Received 743 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
60597803 packets output, 4091836546 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 output buffer failures, 0 output buffers swapped out
SW-4506-B#show interface GigabitEthernet 5/29 counters errors

Port CrcAlign-Err Dropped-Bad-Pkts Collisions Symbol-Err
Gi5/29 0 0 0 0

Port Undersize Oversize Fragments Jabbers
Gi5/29 0 0 0 0

Port Single-Col Multi-Col Late-Col Excess-Col
Gi5/29 0 0 0 0

Port Deferred-Col False-Car Carri-Sen Sequence-Err
Gi5/29 0 0 0 0


what can i do, on the switch side to check if it is the switch port causing the issue'

thanks,

 

[SweetRevelation]

Simplest thing is to just try plugging it into a different switch port. That port is not seeing electrical signal at all from the remote side, it's showing down/down. There's not a whole lot that can be done if it's not even seeing signal.

 

[VinceWhirlwind]

A quick test I would do is to nail the ports on either side of this link to 100Mb and see if they come up. This is a quick way of seeing if your cabling is duff.