Even though the following sections are not critical to make a router or switch work on a network, they are still really important. Lets g
through configuration specific commands that are particularly helpfull when administrating your network. You can configure the following
administrative functions on a router and switch:
Hostnames We use hostname command to set the identity of the router. Hostname are locally significant
and it does not effect how the router perform on internetwork, but is still important because it is often used for authentication
purpose in many WANs.
router# Config t
Banners The reason for having banner is to give any and all who attempt to Telnet or sneak into your
network a little security notice and are good because you can create and modify. There are 3 types of banner. MOTD, Login banner
and Exec banner.
Message fo the day (MOTD) banner are mostly used banner because they give a message to anyone connecting to the router via Telnet
or and aux port even through a console port.
router(config)#banner motd * If you are not authorized to be in practonet network, you must disconnect immediately *
The simple syntex for MOTD banner is router# banner motd *(special character) ----(Message)---- *(Same special character ends line)
You can configure a line-activation (exec) banner to be displayed when EXEC processes such as a line activation or an incoming
connection to a VTY line have been created. Simply initiating a user exec session through a console port will activate the exec banner.
You can configure a login banner for display on all connected terminals. It will show up after the MOTD banner but before the login
prompts. This login banner can’t be disabled on a per-line basis, so to globally disable it you’ve got to delete it with the
no banner login command.
There are five passwords to secure your Cisco routers: console, auxiliary, telnet (VTY), enable password, and enable secret. The enable
secret and enable password are the ones used to set the password for securing privileged mode. Once the enable commands are set, users
will be prompted for a password. The other three are used to configure a password when user mode is accessed through the console port,
through the auxiliary port, or via Telnet.
- Enable Passwords
This sets the enable password on older, pre-10.3 systems, and isn’t ever used if an enable secret is set.You set the enable passwords
from global configuration mode like this:
router(config)#enable password practonet
- Enable Secret Passwords
secret - The newer, encrypted password that overrides the enable password if it has been set. You set the enable passwords from
global configuration mode like this:
router(config)#enable secret practonet
- Telnet Passwords
To set the user-mode password for Telnet access into the router or switch, use the line vty command. IOS switches typically have 16 lines,
but routers running the
Enterprise edition have considerably more.
router(config)#line vty 0 15
* here telnet is the password
- Auxiliary Password
To configure the auxiliary password on a router, go into global configuration mode.
router(config)#line aux 0
* here aux is the password
Setting descriptions on an interface is another administratively helpful thing, and like the hostname, it’s also only locally significant.
One case where the description command comes in really handy is when you want to keep track of circuit numbers on a switch or a router’s
serial WAN port.
Here’s an example on switch:
practonet(config-if)#description Sales VLAN Trunk Link
And on a router serial WAN:
Router(config-if)#description WAN to Miami
You can view an interface’s description with either the show running-config command or the show interface—even with the show interface description
Current configuration : 855 bytes
description Sales VLAN Trunk Link
practonet#sh int f0/1
FastEthernet0/1 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is ecc8.8202.8282 (bia ecc8.8202.8282)
Description: Sales VLAN Trunk Link
MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
practonet#sh int description