Why it is essential for a LAN administrator to understand VLANs? What criteria would be used to determine how many VLANs a department in a medium size company would typically need?
VLAN technology is fantastic as it offers added enhancements to networks and provides multiple pathways to run numerous services in isolated environments without sacrificing quality, availability, and network speed. Many administrators and IT professionals, however, are unaware of the level of security on their VLAN. One of the first aspects in VLAN-based security takes place on the physical level which ensures that unauthorized access is prevented. Removing console-port cables, introducing a password-protected console, and adding specified timeouts should be encouraged.
Avoiding the use of VLAN1 (which is the default VLAN) is also a great thing to do as VLAN1 causes a higher security risk due to offering direct access if a backbone is used. Another thing one can do is disable any high-risk protocols on any port that does not require them. Controlling Inter-VLAN routing using IP access lists allows normal traffic flow but does not expose the networks that need protection. By following these steps, a LAN administrator should be well on the way in creating a secure VLAN, after all, a network is only as strong as its weakest link! These are some of the reasons why a LAN administrator must completely understand VLANs.
Some criteria that a medium-sized company would want to consider when figuring out how many VLANs are needed are broadcast and general network traffic, rate of company/network growth, cost of moving the network equipment, the type of networking equipment used and how they function as well as their traffic types, and finally any security concerns such as if the company works with any sensitive data. VLANs are not just for larger companies anymore; any sized company can benefit greatly by implementing VLANs, as long as the proper research, installation, and maintenance takes place.
Reid, Doug. “VLAN How To: Segmenting A Small LAN.” Small Net Builder. www.Smallnetbuilder.com. Web. 20 June 2007. Retrieved 17 July 2017.
“VLAN Security Tips – Best Practices.” Firewall. Firewall.cx. Web. Retrieved 17 July 2017.