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Cisco 3750 Master switch question

I have worked with Cisco 3560 switches before.  Generally, we have several switches in three different bindings, connected via fiber run another 3560 switch and router in the building where WAN comes into facility via fiber

I currently have 3560s deployed and the gbic connector in the old "master switch" would split between different buildings on lan.

Probably more information than what is needed here but . . .

This 3750 is a new animal to me.  My guess it is more of a true "master switch" where each interface has it's own IP.  I have consoled into the switch and I am just trying to understand this.

I was trying to set up the 3750 like it was just another switch, like the 3560s, inly with 12 SPFs.  

Is my guess correct, and is it possible not to configure it as a Master switch and just have one IP on the entire switch rather than separate IPs for each interface.  I am obviously not understanding what I see when I go into configure the switch.

The pic below just shows three new 3560s that I will be deploying and already accessible on via CNA.  The one on top is the 3750 that I am trying to configure via CLI but I can't get green lights on the interface I am trying to use an interconnect cable on.  Like I said, I suspect I don't understand the basic differences between the 3750 and the 3560s I know pretty well.

I was planning on having several weeks before I needed to deploy, but several weeks has turned into several hours or a few days at most.

Thanks
3750.jpg
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Mixmangle
Asked:
Mixmangle
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3 Solutions
 
that1guy15Commented:
The 3750 should come setup with all ports as switchports. So if you only want one IP on the switch then just give an IP address to VLAN1 or whatever is your management vlan and configure your SFP ports as you would a normal switchport.
If you do not want routing setup on the switch just enter "no ip routing" to ensure the switch only operates at layer 2.
To check to make sure the ports are switchports check to make sure they do not have the "no switchport" command on them.
Configuring the 3750 should be just like the 3560.
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MixmangleAuthor Commented:
I had reset the switch to start with, but I might have messed something else.  I will go thru it again when I am back in.

So, the big advantage to this 3750 with 12 SPF slots over a 3560 is

1. the 12 SPFs allow for multiple connection types (intercontect, LC-ST or SC, etc . . .) and

2.  The huge cable that allows stacks of these to be connected from behind?  

Can you explain to me the Master Switch concept?


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that1guy15Commented:
"Can you explain to me the Master Switch concept?"
Im not sure i understand what you mean by "master switch".  Im guessing since you are connecting different models to this switch you are not talking about the master switch of a stack.
Assuming you mean the main switch that all other switches connect to or aggregate traffic into then "Core Switch" would be a more appropriate term. Your other three switches would be considered access switch. these are the switches that all end devices connect to for network traffic. Access switches then uplink to the core switch were all traffic is centralized and sent to the proper location. This setup is called a "collapsed core" setup since it does not separate the core switches from middle switches which are called distribution switches. This is all part of the "cisco three layer hierarchical model". here is a link that gives a little more details on this model.
http://www.semsim.com/ccna/ccna-study-guide.asp?ain=57 
So the access switches basically segregate traffic into VLANs and function as layer 2 devices. The traffic is then sent up to the core switch which usually routes the traffic (layer 3) either to another vlan, network or the internet. So usually on your core switch you would want routing enabled. If you do not enable routing on your switch you will need to connect your switch to a router so that routing can be accomplished within your network.
I hope this is what you are asking for and helps some.  
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MixmangleAuthor Commented:
Yes it does.  I only have one 3750 so I'm sure it has to do with stacking these and connecting the huge Interconnect in the back betweens switches.
But when I rest and go thru the same confi I use for the 3560s, here's what I get when I try connecting the Interneconnect cable on front (see picture) between a 3560 and the 3750
%PHY-4-SFP_NOT_SUPPORTED: The SFP in Gi1/0/1 is not suppor
ted
After a reset, if I am simply giving it a name, setting IP and subnet, I do't understand wy the interconnect won;t light up on the 3750.
I don't have any way to access this switch except via CLI and then, once interconnected to other switches.  (Cables that allow connection between spf on 3750and Cat 5 directly on PC are not here yet).  Please tell me I'm making sense.
Ill do it again by the numbers here showing what I am doing in initial config:
 
 
 
 
 
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MixmangleAuthor Commented:
Sorry - - - here's what I am doing after reset
Would you like to enter the initial configuration dialog? [yes/no]:Y
Would you like to enter basic management setup? [yes/no]:Y
 Enter host name [Switch]:  BLA-BLA-SW1
Configure SNMP Network Management? [no]:NO
Enter interface name used to connect to the
management network from the above interface summary: VLAN1
Configuring interface Vlan1:
  Configure IP on this interface? [no]: y
    IP address for this interface: xxx.xxx.xxx.xxx
    Subnet mask for this interface [255.255.0.0] : xxx.xxx.xxx.xxx
    Class B network is 146.63.0.0, 25 subnet bits; mask is /25
Would you like to enable as a cluster command switch? [yes/no]: NO
<After Interfaces are configured>

[0] Go to the IOS command prompt without saving this config.
[1] Return back to the setup without saving this config.
[2] Save this configuration to nvram and exit.
Enter your selection [2]: 2

Enter your selection [2]: 2
Building configuration...
[OK]
Use the enabled mode 'configure' command to modify this configuration.
BLA-BLA-SW1>
Now, once all that is done, if I hook up the Interconnect between one of the 4 GBICs on the 3560 and Port 1 on the 3750, using the yellow Interconnect in the picture, exactly as pictured.  The 3560 lights up green but I get nothing on the 3750 and hyperterminal tells me . . . .
%PM-4-ERR_DISABLE: gbic-invalid error detected on Gi1/0/1,
 putting Gi1/0/1 in err-disable state
I also cant ping the switch and I cant access it via a PC that is hooked into same network as 3560s via Cisco Network Assistant.
I am SURE the IP is correct and subnet also. I am also sure the 3560 is set to ALL not just a particular VLAN and that am indeed resetting the 3750.
Could it be something as simple as the Interconnect.  Is it possible that this Interconnect, which I use al the time between 3560s, is not the correct cable to go into the 3750, even tho SPFs and the Interconnect fit fine???
Thanks
 
 
 
 
 
 
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MixmangleAuthor Commented:
I know I have been calling SFPs "SPFs" and I think I call 3560 switchs 3650 from time to time. But you get the gist from the picture, I'm sure.
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MixmangleAuthor Commented:
I goggled the error and see alot of posts saying there is a way to bypass the error if using a non_Cisco Interconnect or sfps, but these are all CISCO Parts.  Now I'm just not sure the same interconnect I use between 3560s will WORK between a 3560 and a 3750!  You think?
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MixmangleAuthor Commented:

 I know I'm "running up my own tab" here, so to speak. <g>

But  it looks to me like the standard 3560 Interconnect wont work between a 2560 and a 3750.  Wat I need is a connector with LC on both ends and use the SFP modules on both ends. Sound right?  That would explain why I'm getting a green light on the 3560 switch but a "unsupported GBIC" error in Hyper terminal for the 3750.

Is that true.

If so, what I would need to Interconnect between the 3560 and 3750 would be a LC to LC fiber cable?
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rileybauerCommented:
If you are getting "unsupported GBIC" then connectivity will not work. You either have a defective GBIC or it is not a Cisco GBIC. Either one will  cause the error and I dont believe any traffic will flow until that error is resolved. Older cisco equipment did not care when using non-cisco (the larger true GBIC's) but with newer equipment that uses SFP modules you cannot use third party SFP modules.
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MixmangleAuthor Commented:
I researched and the yellow interconnect cable used between two 3560s gbics is not listed by cisco for any cable compatible with a 3750. So I still think the
problem is the cable. The same cable works fine whin connecting the 3560 to another 3560 and none of the 3750 ports will work with cable. I will get my hands on an LC to LC connector tomorrow and try that. If it works, and the 3560 interconnect works between two 3570s than the problem must be incompatibility, right?
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that1guy15Commented:
The reason you are having a problem with your inter-connect cable is you can only stack like models. So a 3750 can only connect to 3750s and 3560s can only connect to 3560s. The reason for this is when you stack cisco switches they act like a server cluster. The appear as a single switch and all run off a master config file. So the stack would have issues trying to support multiple models of switch. make sense?
Also i agree on the SFP statement made by rileybauer. Cisco devices are very picky on the SFP you use in their equipment. I also have heard of non-cisco SFPs working but I have also seen issues arise while using these. For stability I would suggest getting your hands on a couple cisco SFPs and using those to interconnect your switches with trunks.
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MixmangleAuthor Commented:
Thanks, thatguy 15.  

I figured that out already. In my original post I mentioned that I was interconnecting a 3560 and 3750 and the picture shows this as well.  I think you must have missed that at the start.

I just attached an LC to LC connector I had to rob from somewhere else, and everything is fine.

I should always start my switch/router related posts with . . . . "I usually miss something obvious, so be careful you don't get sucked into my delusion!!"

Thanks people.

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that1guy15Commented:
Sorry about that. I was unsure of what your ? was geared towards, either stacking or design.
glade you are up and going though.
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