Discussion of Cisco Catalyst 2960 series switches and miscellaneous chatter about SFP modules (started with OT posts from EtherREGEN thread)

[who]

On 6/25/2019 at 2:27 AM, stevebythebay said:

Hope someone can help:

 

Got  the switch on eBay, and reset to factory, based on documentation from Cisco site..  However, the factory reset does not reset the user/password to how it left the factory it seems.  I get no positive results using cisco/cisco or Cisco/cisco or Admin/cisco, no user/cisco, etc.  I suspect it has the last owner's user/password in place...

 

When I try to telnet into the Cisco I get "Password required, but none set".  Any idea on how to fix that?  And I've not found any Cisco documentation that suggests how to fix it either.

 

FYI: I've got a Mac (no Windows system).  Not really familiar with using telnet options that might pass to the Cisco to allow it to let me in.

 Hi Steve,
I'm new to this forum. Let me help with your question. The 'only' way to get into a typical Cisco device without any configuration is via the console port. All remote connections are disabled by default. This is the reason why you see the 'Password required, but none set'.
This is just a good security practice.

You'll have to configure your switch with login as well as privilege passwords to 'fully' access all its features remotely.
If anyone is interested in doing so, let me know.

[who]

1 hour ago, Superdad said:

On behalf of Audiophile Style and UpTone Audio, welcome to the forum! And it’s quite generous that your first post here is to share your knowledge and assist others with the answer to a tech question. Thanks very much for that. Looking forward to seeing what else you might contribute.

Regards,

—Alex C.

Thanks for the welcome Alex.

 

I'll just continue where i left off. In order to access the console, you'll need a Cisco console cable (search for 'cisco console cable' on eBay). I wouldn't pay more than $5 for it.

It's the cyan flat looking cable, one end it's the DB-9 serial connector, the other end is the RJ-45 (please do not plug this into your LAN ports). You'll need a serial port on your computer. Most recent machines don't have the serial port anymore so you'll need to get a usb-to-serial adaptor. There are some console cable with USB -> RJ-45 (<$10) but those are not original and I have no experience with them (it'll probably work the same as with the usb-to-serial adaptor).

Once you have those connected (computer's serial port -> console cable -> console port), it's time to fire up your terminal program (not your Window's command prompt nor Apple's terminal console).
PuTTY is a very popular and freeware terminal program.
https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

 

Run 'putty.exe'
Select 'Connection Type' as Serial and type in the COM port # of your serial port in the 'Host Name (or IP address)' field.
eg, COM3, COM4, etc.
Use the default speed of 9600.

Click on 'Open' and you should get a terminal window. Press ENTER and you should get a prompt if everything is done correctly.

To be continued...

[who]

On 7/15/2020 at 12:02 AM, who said:

To be continued...

 

For those who's gotten this far, you'll need the following information to complete the switch setup using console (assuming the switch does not have any configuration).

There are other methods (will discuss those another time) but this is probably the most common with network engineers.

 

- IP address to be assigned to the switch
- Subnet Mask
- Default gateway (router)

- Enable (privileged) password

- Telnet/SSH password

The following is copied from Cisco documentations.

 

Follow these steps to complete the setup program and to create an initial configuration for the switch:

---

Step 1 Enter Yes at these two prompts.

Would you like to enter the initial configuration dialog? [yes/no]: yes  

At any point you may enter a question mark '?' for help.

Use ctrl-c to abort configuration dialog at any prompt.

Default settings are in square brackets '[]'.  

 

Basic management setup configures only enough connectivity

for management of the system, extended setup will ask you

to configure each interface on the system.  

 

Would you like to enter basic management setup? [yes/no]: yes  

 

Step 2 Enter a host name for the switch, and press Return.

On a command switch, the host name is limited to 28 characters; on a member switch to 31 characters. Do not use -n, where n is a number, as the last character in a host name for any switch.

 

Enter host name [Switch]: host_name  

 

Step 3 Enter an enable secret password, and press Return.

The password can be from 1 to 25 alphanumeric characters, can start with a number, is case sensitive, allows spaces, but ignores leading spaces. The secret password is encrypted and the enable password is in plain text.

 

Enter enable secret: secret_password  

 

Step 4 Enter an enable password, and press Return.

 

Enter enable password: enable_password  

 

Step 5 Enter a virtual terminal (Telnet) password, and press Return.

The password can be from 1 to 25 alphanumeric characters, is case sensitive, allows spaces, but ignores leading spaces.

 

Enter virtual terminal password: terminal-password  

 

Step 6 (Optional) Configure Simple Network Management Protocol (SNMP) by responding to the prompts. You can also configure SNMP later through the CLI, the device manager, or the Network Assistant application. To configure SNMP later, enter no.

 

Configure SNMP Network Management? [no]: no  

 

Step 7 Enter the interface name (physical interface or VLAN name) of the interface that connects to the management network, and press Return. For this release, always use vlan1 as that interface.

 

Enter interface name used to connect to the management network from the above interface summary: vlan1  

 

 

Step 8 Configure the interface by entering the switch IP address and subnet mask and pressing Return. The IP address and subnet masks shown below are examples.

 

Configuring interface vlan1: Configure IP on this interface? [yes]: yes

IP address for this interface: 10.4.120.106

Subnet mask for this interface [255.0.0.0]: 255.0.0.0

 

Step 9 Enter Y to configure the switch as the cluster command switch. Enter N to configure it as a member switch or as a standalone switch.

 

If you enter N, the switch appears as a candidate switch in the Network Assistant GUI. You can configure the switch as a command switch later through the CLI, the device manager, or the Network Assistant application. To configure it later, enter no.

 

Would you like to enable as a cluster command switch? [yes/no]: no  

 

You have now completed the initial configuration of the switch, and the switch displays its initial configuration. This is an example of output that appears:

 

The following configuration command script was created:

hostname switch1

enable secret 5 $1$Ulq8$DlA/OiaEbl90WcBPd9cOn1

enable password enable_password

line vty 0 15

password terminal-password

no snmp-server

!

no ip routing  

!

interface Vlan1

no shutdown

ip address

10.4.120.106 255.0.0.0

!

interface FastEthernet0/1

!

...<output abbreviated>

!

end  

 

Step 10 These choices appear:

 

[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.  

If you want to save the configuration and use it the next time the switch reboots, save it in NVRAM by selecting option 2.  

Enter your selection [2]:2  

 

Make your selection, and press Return.

[who]

On 7/20/2020 at 10:41 PM, Ricardo007 said:

I mean you plug the console cable to one of the USB ports on your laptop, how you know the correct COM number the USB port you use?

 

also by "interface" what is meant? is it the LAN port 1 for example of the Cisco? and you have to configure each of the 8 ports plus the 2 SFP ports?

 

When you have to enter the IP adress, most of the non commercial  Internet provider subscriptions does not allow you to get static IP, you get only dynamic IP which change over time. Is that a problem if the switch has a dynamic adress and not a static one?

 

Then you have to know the dynamic adress of your switch, how to?

 

Sorry for these numerous beginner questions....

 

 

 

>I mean you plug the console cable to one of the USB ports on your laptop, how you know the correct COM number the USB port you use?

 

In Windows, open up your Device Manager, scroll down to 'Ports (COM & LPT)', expand it and you'll see the COM# beside the device.
If you have more than one, first unplug the one you're going to use, wait a few seconds for the device manager to update it's content, plug it back in and take note which appears. That's the one you've just plugged in.

 

 

>also by "interface" what is meant? is it the LAN port 1 for example of the Cisco? and you have to configure each of the 8 ports plus the 2 SFP ports?

 

In the example given above, it shows vlan1. It's a virtual interface for VLAN1 for the switch. It's not assigned to any particular port. You can access that IP you've given to the switch from any ports in vlan1 (which is default for all ports).

In short, configure vlan1 interface. You don't need to assign any IP addresses to individual ports in most scenarios.

>When you have to enter the IP adress, most of the non commercial  Internet provider subscriptions does not allow you to get static IP, you get only dynamic IP which change over time. Is that a problem if the switch has a dynamic adress and not a static one?

Then you have to know the dynamic adress of your switch, how to?

 

The dynamic public IP address resides on the WAN port of your Internet router.

The LAN port of your Internet router is almost certainly a private IP range, (10.x.x.x, 172.16.x.x, 192.168.x.x)
Almost all consumer routers will use 192.168.x.x

 

You can control your internal LAN addresses. If you have not meddled with it, it's assigned by your internet router (not your ISP).

 

Look at DHCP server settings in your internet router to figure out the range of addresses that is used to dynamically assign your internal network. You will need to choose an address that is NOT in this range to assign to the switch. If you can provide a screenshot of this DHCP server page on your router, I can help explain further.
  

In your Windows command prompt, type 'ipconfig' to view your IPv4 address, subnet mask and gateway.

I have IPv6 running at home so ignore those portions.

 

 

[who]

On 7/22/2020 at 10:32 AM, Ricardo007 said:

Thank you so much. 

Some network expertise very much appreciated once one has played with better power supplies, clock, câbles etc... And moved upstream to switches and routiers... 

I have question about how to configure thé upload sfp cage as LAN port on Cisco 2960

I want to link 2 Cisco by fiber in order to isolate thé edgerouter from thé unify access point for wifi

 

You're welcome.

 

Just plug in the SFP and connect up the fibre. Default configuration will work.
Please don't have a 'perception' (trying to find a better word to use here) that the SFP has to be an uplink.
Without going into too much detail, just think of it as just another LAN port.

[who]

On 7/22/2020 at 10:44 AM, Ricardo007 said:

If I can ask more... 

In order to get better sound one often says better to have less CPU consumption and less current générall'y speaking circulation within the equipment

One possible way to do so would be to désactivate unused ports ? 

In my example with à stack of 2 isolating Cisco switches on the wireless router to AP leg, I have port1 for input and port 8 (or sfp cage reassigned as LAN port) for example for output, all other ports unused. 

How to désactivate thé unused ports ? 

 

Once you have configured a management IP on the switch (or have console access), you may disable unused ports.
When you have done that, I can guide from there.

Configuring a management IP on the switch is really quite a prerequisite to manage the switch.
I need to know the level of expertise (eg, beginner, basic, advance, expert) in computers/network before continuing as it'll save everyone some time.