Cisco Switches

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Cisco Switches

Hardware

The switches for the private HPC cluster in room 68-822 are Catalyst 3750 series 24-port switches. They are in a stacked configuration meaning that the backbone spans the physical switches in a loop using Cisco StackWise Stacking Cables.

Software

The current software version is Version 12.2(35)SE5, RELEASE SOFTWARE (fc1)

Maintainance

There is a web interface set up on a virtual IP address on the cluster network: http://192.168.0.250/. Alternatively, the switches can be configured by logging into them from a serial port on one of the computers using the light blue cable to connect the serial port to the ethernet-like port on the switch. To do this, on the computer you are using type

# dmesg | grep tty   # To find the serial port
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
00:0b: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
# setserial -g /dev/ttyS0 # To set it up
/dev/ttyS0, UART: 16550A, Port: 0x03f8, IRQ: 4
# minicom -s # This software creates a terminal over the serial port to configure the switch, the first time you run it it is good to configure it 

In minicom you need to change the following:

  • in Serial Port Setup:
    • serial device = /dev/ttyS0
    • Bps/Par/Bits = 9600 8N1
    • Hardware flow control = yes
    • Software flow control = no
  • Save setup as:
    • cisco
  • Exit minicom
# minicom cisco # To start the terminal. Note, there are authorisation commands required to change settings: en (enables the authorisation to change something or see an important setting), conf (enables the configuration for the switch, once authorised).
Switch1> en
Password: 
Switch1# conf
Switch1(config)# exit
Switch1# show version
Cisco IOS Software, C3750 Software (C3750-IPBASE-M), Version 12.2(35)SE5, RELEASE SOFTWARE (fc1)
...

To exit just press Ctrl-A X. See here for configurational information. Alan has all the passwords.

Known Issues

We had an issue a while back where the switch for some reason was resetting the ports. To stop this we fixed the speed to gigabit on the ports that needed it.