Routing and Switching - Chathura Ariyadasa (He/Him/His)

How to copy an Image file to another network device

In general, we copy/upload IOS image files to either flash or bootflash from a TFTP server. In case of timeouts or network delays with the TFTP server, we could use either USB or Memory Slots in order to copy image files to a network device. Once you are done copying the image to flash/bootflash, we can simply configure the network device itself as a TFTP server and can be used to copy image files across other devices. 

NOTE: Please make sure all the devices are in the same subnet 

In our example, we have used 2 Routers. Router 01 is preloaded with the Image files and will be configured as the TFTP server. Router 02 will be the TFTP client. 

Step 01: Make sure, the image file is already copied to the file location (flash or bootflash)

# show bootflash:

Step 02: Configure the Router as a TFTP server. And then assign the relevant image file

(config)# tftp-server bootflash:/“imagename”

Step 03: Log into Router 02 and copy the Image file from the TFTP server (Router 01)

#copy tftp bootflash:


[source: Cisco KB]



Private VLANs (PVLAN)

VLAN provides network isolation and layer 2. Typical VLAN would have a single subnet and all the devices within the VLAN can communicate with each other. But what if you want to put multiple devices within a subnet and do not wish to communicate with each other ? The answer would be the use of Private VLANs (PVLANs).

How it works

PVLANs are actually a set of VLANs. There is a Primary VLAN and one or more Secondary VLANs. 

Primary VLAN – Same as a typical VLAN and the networks are promiscuous, as they will always communicate with each other

Secondary VLAN – These networks are associated with the Primary VLAN and they keep seperated with each other

In Secondary VLANs, there are two types of Networks 

  • Community VLAN – In a community VLAN, the devices will communicate with each other. But the Inter community VLAN does not take place. [ex: Community A and Community B VLANs will have no communication]
  • Isolated VLAN – In an Isolated VLAN, the devices will not communicate with each other. They also have no Inter commuication with Community VLANs.

All the devices can connect to the Primary VLAN. So this allows the devices to share Internet connectivity. Basically, this will act as the default gateway. 

Ports in the Primary VLAN are known as the Promiscuous Ports (P-Ports). Layer 3 switches are placed here and can have SVI (Switch Virtual Interface) configured in the Primary VLAN.

Ports in the Secondary VLANs are known as the Host Ports , as the name suggests these ports are being used to connect the end points (devices).

The below Diagram provides a good explanation

Continue reading “Private VLANs (PVLAN)”

Graphical representation and the configuration

[Kevin Wallace Training, LLC]