DESIGN OF INTERNETWORK MANAGEMENT BASED ON
VLANs
Abstract:Implement VLANs essentially creating smaller broadcast domains at layer 2, means that broadcasts sent out from a node in one VLAN won’t be forwarded to ports configured to belong to a different VLAN. In this paper, we assigning users to VLAN groups on a switch, this help to gain the flexibility to add only the users you want into that broadcast domain regardless of their physical location. This setup can also work to block broadcast storms caused by a faulty network interface card (NIC) as well as prevent an intermediate device from propagating broadcast storms throughout the entire internetwork.
Keywords:VLAN, broadcast, layer2, switch, router, configure,domain
1. Introduction
The layer 2 switched networks are typically designed as flat networks.With this configuration, every broadcast packet transmitted is seen by every device on the network regardless of wether the device needs to receive that data or not.By default, routers allow broadcasts to occur only within the originating network,while switches forward broadcasts to all segments.Oh, and by the way, the reason it’s called a flat network is because it’s one broadcast domain, not because the actual design is physical flat.
The largest benefit we gain by having a layer 2 switched network is that it creates individual collision domain segments for each device plugged int each port on the switch.This scenario frees us from the Ethernet distance constraints,so now larger networks can be issues.For instance,the larger the number of users and devices, the more broadcasts and packets each switch must handle.
Since swiches have become more affordable lately, a lot of companies are replacing their flat hub networks with pure switched network and VLAN environments.All devices within a VLAN are members of the same broadcast domain and receive all broadcast. By default, these broadcasts are filtered from all ports on a switch that aren’t p
VLAN identification is what switches use to keep track of all those frames as they are traversing a switch fabric.It’s show switches identify which frames belong to which VLANs.
Inter-swich Link (ISL)
Inter-switch link (ISL) is a way of explicitly tagging VLAN information onto an Ethernet frame.This tagging information an external encapsulation method (ISL), which allows the switch to identify the VLAN membership of a frame over the trunked link.
By running ISL, you can interconnect multiple switches and still maintain VLAN information as traffic travels between switches on trunk links. ISL functions at a layer 2 by encapsulating a data frame with a new header and cyclic redundancy check (CRC)
The fig 1 above shows that PC1 and PC2 are in the same VLAN 2, let say it is Administration Area, PC0 and PC3 are in another VLAN 3, let say it is Marketing Area. Switcha is a Server and Switchb is a Client.
DESIGN OF INTERNETWORK MANAGEMENT BASED ON VLANs
