Port not enabled

[eliassfeir1]

Hello experts sorry if this is in the wrong section but i'm new here :)

So i'm an IT officer in a company the network is built and based on cisco i have a little to no knowledge regarding to cisco i'm more of a programmer but i decided to start handling and maintaining the switches there so we have a catalyst 2960 switch in the main office server room and two ports were closed (gi0/45, gi0/27) what i tried to do to reopen is the following 

telnet "ip"

enable

put the password 

config t

int gi0/45

no shutdown 

end

write

the port number 45 is now opened and works fine but port number 27 is displaying an orange led not blinking just orange without blink and i tried the command no shutdown still nothing , i tried to shutdown and then no shutdown still nothing orange led no internet access

port 27 belongs to the vlan100 in my case 

any help is highly appreciated and btw how can i limit the users on a single port to let's say 2 users (2 MAC address) storm-control ??

thanks in advance :)

[Philip D'Ath]

"show log" is likely to indicate the issue.  "show interface gi0/27" may also say the issue in the top couple of lines.

Can you show us the port config.  Also is plugged into this port?

[eliassfeir1]

show interface gi0/27 status shows notconnect vlan100 full duplex 

yes it is plugged and i tried it when unplugged also

[Philip D'Ath]

And what does the switch log say about it?

[eliassfeir1]

It was connected to the patch panel directly to the admins office but stopped all of sudden so i switched to another port in order to open it later on and it's not opening currently (tried to connect directly from port 27 to my laptop using RJ45 but nothing happens when i plug it into the port 45 that i recently opened it works and i get internet

show interface gi0/27 shows this

AlfaLabs.SW.CORE#show interface gi0/27
GigabitEthernet0/27 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 442b.0333.6c1b (bia 442b.0333.6c1b)
Description: Port Madroub
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-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 1w5d, output hang never
Last clearing of "show interface" counters never
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 3167
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
16154073493 packets input, 1101883630068 bytes, 0 no buffer
Received 2895094 broadcasts (1319764 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 1319764 multicast, 0 pause input
0 input packets with dribble condition detected
36512660906 packets output, 44814990554330 bytes, 0 underruns
0 output errors, 0 collisions, 21 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
 

[devils_advocate · Accepted solution]

That suggests the port is down at Layer 1 so the switch is not detecting any activity from whatever is plugged into it.

Can you provide the port config?

#show run int gi0/27?

I think looking at this information that the issue is being caused by the fact the port has been manually set to 1Gb as its speed.
See here:

Keepalive set (10 sec)
Auto-duplex, 1000Mb/s, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported

If you are plugging in a host which is set to autonegotiate then the port may not come up if its been manually set to 1000Mb/s.

Try the following:

#conf t
#interface gi0/27
#speed auto

On ports which connect to hosts, its best practice to leave the speed and duplex to autonegotiate to prevent issues like this.

Thanks

[eliassfeir1]

Thank you very much this solved it i tried it now blinking green and internet access :) what do you think that caused this issue ? it was working fine all of sudden the internet became so slow i opened the routers client list and there was an unknown ip using the whole bandwith! probably a virus or trojan then it stopped 

[devils_advocate]

Sounds like somebody configured the port to be manually set at 1000Mb.

If one side is manually set (i.e. the switchport side) and one is auto (i.e. the client) then you can have issues.

Check the rest of your ports which you know connect to hosts (Printers, PC's, Laptops etc) and ensure they are set for auto on both speed and duplex.

Basically do a #show run and spacebar down until you see all the interface configurations. If you see anything like 'speed xxxx' or 'duplex xxxx' then it has been set manually.

As mentioned, only change this on host ports, not on connections between switches like trunks etc as it may cause downtime for those.

Thanks

[eliassfeir1]

Ohh i see one last question some of my ports are configured with a security or restriction when i add a pc the port stops can i use this command to remove security:

-no switchport port-security

??

thanks in advance

[Philip D'Ath]

Yes you can, providing that it is port-security that is causing the issue.

[Philip D'Ath]

What is plugged into this port?