VLAN

Jeg kan ikke rigtig se hvad der skulle være af ulemper ved VLAN, det giver der i mod en masse forskelen i forhold til at dele dit netværk op.

Det kræver slevføldig at man får det struktureret rigtigt osv.

Kan dette bruges?

Cons & Limits

VLANs limit - it is possible to create only 4094 different VLANs for the same network, because of the 12 bit VID identifier. Each VLAN has its own unique ID between 0 and 4096, whereby 0 and 4096 are reserved, thus the switch knows whereto route the frame. This should be more then enough for today, in most companies but could prove as a bottleneck in the future in the same manner IPV4 did.

Security limits - in a network spanning more than a single geographical location the traffic will usually go through 3rd party ATM clouds or even through the internet when using Subnet based VLANs this exposes the traffic to potential sniffing and "Man in the middle" attacks which could be hard to deal with unless higher layers offer additional security on the traffic. Additionally a virus which is spreading across a VLAN is hard to stop as a VLAN acts a LAN for that matter allowing the virus to spread even geographically if a network is large enough. Another problem with using VLANs is that they generate also a massive traffic load on any firewalls located between different geographic locations and in most cases requires having very powerful and expensive Firewalls to ensure the network security on the LAN level.

Managerial Overhead - when using hard configured VLANs such as port based or MAC based it requires quite a lot of managerial work to manage the networks as they evolve and change with time (keeping track of port assignment or MAC assignment per VLANs is time consuming). On the other hand the usage of Subnet based VLANS requires stronger switches which cost more money, and also adds additional switching latency because it is required to decipher the layer 3 header partially

Det kan semi bruges. Det er ihvertfald mere konkret end det jeg har kunne oppstøve på nettet.