What is Private VLAN and Port Types ?

Private VLANs provide layer 2 isolation between ports within the same broadcast domain. 


There are three types of PVLAN ports:

• Promiscuous— :->A promiscuous port can communicate with all interfaces, including the isolated and community ports within a PVLAN.
• Isolated—:-> An isolated port has complete Layer 2 separation from the other ports within the same PVLAN, but not from the promiscuous ports. PVLANs block all traffic to isolated ports except traffic from promiscuous ports. Traffic from isolated port is forwarded only to promiscuous ports.
• Community:->— Community ports communicate among themselves and with their promiscuous ports. These interfaces are separated at Layer 2 from all other interfaces in other communities or isolated ports within their PVLAN.

What is a Difference Between NAT and Proxy Server ?

Proxy Server:->

Proxy server An application-based translation of network access requests.Provision for local user authentication for access to untrusted network. Logging and control of port/protocol access may be possible. Normally used to connect two networks.

NAT :->

Network Address Application-based translation of requests for service or Translation (NAT) connection to an external network. No user authentication is possible, and port/protocol filtering is not usually performed here. Used to redirect requests through one interface. Requests for connection at outside interface must have originated from inside host or they are dropped.

What is DMZ ?

A computer host or small network inserted as a “neutral zone” between a company’s private network and the outside public network. The DMZ prevents outside users from getting direct access to a server that has company data. (The term comes from the geographic buffer zone that was set up between North
Korea and South Korea following the United Nations “police action” in the early 1950s.) A DMZ is an optional and more secure approach to a firewall and effectively acts as a proxy Server.