Monthly Archives: October 2019

Link Aggregation on Cisco Switch

First, you need to access the console of your Cisco Switch.

In our example, we are going to use an Opensource software named Putty and a computer running Windows.

The Putty software is available on the putty.org website.

After finishing the download, run the software and wait for the following screen.

To access the console of a Cisco Switch model 2960 or 3750, you will need to select the Serial Connection category and use the following options:

• Connection type: Serial
• Serial line: COM1
• Speed: 9600

If COM1 does not work you will need to try to use COM2, COM3, COM4 or the next.

Using either the console, telnet or ssh, connect to the command-line of your switch and log in with a user who has administrative privileges.

On the prompt screen, enter the administrative login information.

After a successful login, the console command-line will be displayed.

Switch>

Use the enable command to enter the privilege mode.

Switch> enable

Use the configure terminal command to enter the configuration mode.

Switch# configure terminal

Create a new vlan, select an identification number and add a brief description.

Switch(config)# vlan 100
Switch(config-vlan)# name Voip Network
Switch(config)# vlan 200
Switch(config-vlan)# name Data Network
Switch(config-vlan)# exit

On the configuration mode, you need to clear all the configuration from the switch port.

Switch(config)# default interface gigabitEthernet 0/21
Switch(config-if)# default interface gigabitEthernet 0/22

On the configuration mode, add the switch ports to a link aggregation group.

Switch(config)# interface gigabitethernet0/21
Switch(config-if)# channel-group 1 mode active
Switch(config)# interface gigabitethernet0/22
Switch(config-if)# channel-group 1 mode active
Switch(config-if)# exit

In our example, the switch ports 21 and 22 were configured as members of the link aggregation group 1.

To configure the link aggregation ports as a Vlan member, you need to use the following commands.

Switch(config)# interface Port-channel 1
Switch(config)# switchport mode access
Switch(config-if)# switchport access vlan 200
Switch(config-if)# exit
Switch(config)# exit

In our example, the Switch port group 1 was configured as a member of VLAN 200.

To configure the link aggregation ports as a Trunk, you need to use the following commands.

Switch(config)# interface Port-channel 1
Switch(config)# switchport mode trunk
Switch(config-if)# switchport trunk native vlan 1
Switch(config-if)# switchport trunk allowed vlan add 1,100,200
Switch(config-if)# exit

In our example, the Switch port group 1 was configured as a trunk.

The trunk configuration allows the communications of Vlans 1, 100 and 200.

Don’t forget to save your switch configuration.

Switch# copy running-config startup-config

You have successfully configured a link aggregation on a Cisco switch.

WinSCP as Sudo Root

To allow for a WinSCP session to operate as sudo the following string can be added.  Thai ia most useful when attempting to change the content of config files that are owned by the root account.

sudo su -c /usr/lib/sftp-server

Found on the advanced settings page for your site: