Posts Tagged ‘catalyst’

Initial Cisco switch configuration

June 28, 2012

First steps you need to do when you unpack your Cisco switch, for example Catalyst 2960, are configuring passwords and IP access via telnet and ssh. Cisco networking switches and routers have two primary operation modes: User (unprivileged) and Enable (privileged). In User mode you can simply look around, but in Enable mode you can reboot a switch, change configuration info, as well as screw everything up. You are safe in User mode. Switch also has tons of hierarchical configuration modes where you perform actual configuration.

Switch has three passwords: two for User mode (for connection from serial console and for external telnet and ssh connections) and one for Enable mode. Here is how you configure passwords after you unpack your switch and connect the serial cable.

Enter configuration mode:

configure terminal

Configure console password:

line console 0
password pass1

Configure ssh and telnet password:

line vty 0 15
password pass2

Configure Enable password:

enable secret pass3

‘login’ command tells switch to ask for User mode password. It doesn’t do that by default. Switch has 16 virtual (ssh and telent) consoles, that is why you see ‘0 15’ range in ‘line vty 0 15’ command.

Now to get IP access to the switch you need to configure so-called ‘VLAN 1 interface’:

configure terminal
interface vlan 1
ip address
no shutdown

ip default-gateway

VLANs are not subject of this topic. But to make it a bit more clear, VLAN 1 is a special VLAN where all switch ports are connected. It’s done so that you could connect to the switch by telnet/ssh from any port. ‘no shutdown’ command here brings interface up. It’s disabled by default.

After you’ve made an initial configuration, your changes are active but not saved. After a reload you will have empty switch configuration. To save the configuration changes run:

copy running-config startup-config


DC Networking

November 26, 2011

Misc photos from our server rooms. This time networking.

Here I post pictures only from central building. There are also several networking rooms in other buildings. Network core is build primarily on Cisco routers and switches. Branches use HP.

Click pictures to enlarge.

Here are the routers, switches, fibre distribution panels, etc.

Cable mess.