Question

Discussion Prompt(s)

VLANs and VTP

What role do VLANs play in modern networks and network design?

How can the VLAN Trunking Protocol (VTP) and VTP Pruning be used by network administrators or technicians in order to increase overall efficiency?

From a network administration perspective, do you see any potential problems that could arise as a result of using VTP?

Answer 1

VLANs can be used for different groups of users, departments, functions, etc., without needing to be in the same geographical area. VLANs can help reduce IT cost, improve network security and performance, provide easier management, as well as ensuring network flexibility. VLANs address issues such as scalability, security, and network management. Network architects set up VLANs to provide network segmentation. Routers between VLANs filter broadcast traffic, enhance network security, perform address summarization, and mitigate network congestion.

VTP, which is available with Cisco Catalyst products, provides efficient ways to send a VLAN through every switch. There’s also the option of VLAN pruning which will avoid sending traffic through some switches. Users can make these systems pruning eligible or pruning ineligible.One concept in VTP is that larger scale networks may need to be limited in terms of which switches will act as the VLAN servers. VTP offers various options for recovery after a crash or for efficiently serving up redundant network traffic.

Although VLAN Trunking Protocol does its job in distributing VLAN database from server to all the other client switches. It has some major issues when wrongly implemented or trunk negotiation between switches.

• Always reset the revision number of a switch before adding to production network. It happened almost everywhere.
• Always Hard code a trunk link between two different VTP domains. In the case of keeping the default setting of trunk config in just one VLAN supported by a switch.Some low end switches (2960, 2950,etc) have a maximum vlans support. If you make these switches into client mode. They will cause various issues, and the best solution would be to make them transparent.