03-07-2009 01:08 AM - edited 03-06-2019 04:26 AM
Hi
I'll installing a 3560 switch unto our LAN. I'm replacing a 2950 switch. I removed the old switch & placed the new 3560 in the cabinet. Plugged in everything. Lastly I plugged in the up link port. Using Fibre LC-ST but I have no Link light flashing. All devices on this switch is not getting any connectivity. What do I have to check for? please have help urgently. do know what to check next???
03-07-2009 01:57 AM
Have you admin'd up the interface on the 3560?
ie
interface gigx/x
no shut
03-07-2009 02:12 AM
I'm Gonna try that now.
I''l let you know the out come.
03-07-2009 02:41 AM
It's still not up.
Below is my Config:
Building configuration...
Current configuration : 4866 bytes
version 12.2
no service pad
service timestamps debug uptime
service timestamps log uptime
no service password-encryption
hostname za-plz-basf-sw10
enable secret 5 $1$wAnM$2CKCX4zIyIdMB3MPR5w8c.
enable password ****
no aaa new-model
system mtu routing 1500
ip subnet-zero
no file verify auto
spanning-tree mode pvst
spanning-tree extend system-id
vlan internal allocation policy ascending
interface GigabitEthernet0/1
switchport trunk encapsulation dot1q
switchport mode trunk
interface GigabitEthernet0/2
switchport trunk encapsulation dot1q
switchport mode trunk
interface GigabitEthernet0/3
switchport trunk encapsulation dot1q
switchport mode trunk
interface GigabitEthernet0/4
switchport trunk encapsulation dot1q
switchport mode trunk
interface Vlan1
no ip address
shutdown
interface Vlan20
ip address 10.86.66.X 255.255.255.0
ip classless
ip http server
snmp-server community public RO
-plane
line con 0
line vty 0 4
password ******
login
line vty 5 15
password *****
login
end
03-07-2009 03:47 AM
Hi
Are the interfaces admin'd on both switches, if so you jave a layer 1 issue, trying changing the cables
03-07-2009 02:56 PM
Kaamil
The first thing that I would suggest would be to check the patch cable connected to the uplink port. Can you try a different cable? Can you bring back the 2950 that you were using, power it up, and plug the uplink cable back into it and see if link comes up on it?
In the part of the config that you posted it looks like all ports are configured as trunk ports? Is this correct? Is this the way that the 2950 was configured?
Is it possible that there is a speed mismatch between the new switch and the device that it connects to on the uplink? Can you post the output of show interface for the uplink port?
HTH
Rick
03-08-2009 07:08 AM
Hello Kaamil,
>> Using Fibre LC-ST but I have no Link light
compare the GBIC you had on the C2950 with the SFP in the C3650 one can be for single mode and the other for multi-mode fiber
if the SFP is for MM and the fiber is SM most of optical power is lost (SM fiber cuts off the superior modes)
Hope to help
Giuseppe
03-09-2009 07:18 AM
A simple thing to check is if you have TX connected to RX on the other switch. Swap the optical cable in one switch and try the "no shutdown" in both switches and see if it comes up.
03-09-2009 05:04 PM
if the SFP is for MM and the fiber is SM most of optical power is lost (SM fiber cuts off the superior modes)
Hi Giuseppe,
Most of the power is not lost from MM to SM but there is not enough power going inside the SM fiber.
MM fiber diameter is 50micron/62.5micron whereas SM have 8-10micron so a transmitter made for MM fiber is not able to launch enough power into SM because of size mismatch.
Even more modes in Multimode is a problem as it decreases your distance.
03-09-2009 04:53 PM
As suggested in other posts
1. Check your GBIC/SFP are Single mode/Multi mode. Is your fiber Single or Multimode.
2. Check the wavlength of both SFP/GBIC also
If all above matches i hope your things should work.
3. If doesnot work then swap your Tx/Rx.
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