Hi, all,
Our office is now established with new devices Cat2960 & Cat3560, but I found the state changed frequently, as the following :
Jun 5 09:33:43: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to down Jun 5 09:33:45: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to up Jun 5 11:56:30: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to down Jun 5 11:57:01: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to up Jun 5 12:43:26: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to down Jun 5 12:43:44: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to up .Jun 5 13:25:51: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to down .Jun 5 13:26:15: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to up Jun 5 14:23:05: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to down Jun 5 14:23:09: %LINK-3-UPDOWN: Interface GigabitEthernet0/21, changed state to up gd-hko-sw2960-2# sh int gi0/21 GigabitEthernet0/21 is up, line protocol is up (connected) Hardware is Gigabit Ethernet, address is 001f.2732.f395 (bia 001f.
2732.f395) 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) Full-duplex, 1000Mb/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 0 bits/sec, 0 packets/sec 5 minute output rate 1000 bits/sec, 1 packets/sec 1549674 packets input, 389814712 bytes, 0 no buffer Received 20830 broadcasts (4040 multicasts) 0 runts, 0 giants, 0 throttles 1 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 4040 multicast, 0 pause input 0 input packets with dribble condition detected 19451473 packets output, 2816921787 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 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 gd-hko-sw2960-2#------------------------------------- end------------------------------------