Layers

In todays growing world of networks, there is a need for Remote Mangament.All the devices today come with all the 7 layers of OSI that help the network administrator to remotely mange the sites.

Although switch works on layer 2, but it has to be assigned an IP address. But switches do not natively support layer 3 address. For that there is a logical layer 3 interface SVI (Switch virtual interface) on switch that provide layer 3 IP connectivity to the switch. So a managemnt IP address must be configured on the SVI and default IP gateway for remote management.

Now SVI might be a new name for most of us. I want to elaborate more abt it, what i learnt while googling it.

Well,SVI's make the switch understand the layer 3 addresses. SVI's are generally configured for VLANs and they help the VLANs to communicate with each other. As we know that there are no physical interfaces for VLANs. While doing the VLAN configuration we have to create vlans on every switch and assign vlan memberships to the ports. By this we are creating a one to one mapping between the VLANs and the SVI's (What i understood is that there will be as many SVI's as the VLANs we have created..Fahad bhai plz corerct me if iam wrong).

By default, there is only VLAN1 enabled on the switch ports hence in default settings, a SVI is created for a default VLAN 1 and if assign a managemnt ip to a switch port, it can be surely manged remotely because of SVI.

Another thing i learnt mean while was related to Multi layer switch. If we want to upgrade the layer 2 switch to LAyer 3 switch i.e. multilayer switch then there is a software image called SMI (Standard Multi layer Image) and its enhanced version is Enhanced multilayer image. (EMI)

so to add layer 2+ functionalities in a switch, the Switch IOS must be upgraded with these images.

So according to my understanding, if u have to ip configure ur layer 2 switch, then SVI is there to make the switch understand it. On the other hand if you want to make ur layer 2 switch a multilayer switch that can perform the layer 3 functionalties (access
control lists (ACLs), quality of service (QoS), static routing, and the
and the Routing Information Protocol (RIP) etc) you have to upgrade the IOS with the SMI and EMI images.