Every spanning tree switched network or broadcast domain has a switch designated as the root bridge. The root bridge serves as the reference point for all spanning-tree enabled switches. The spanning tree algorithm determines which redundant paths to block. It is selected as an election process. The figure below illustrates the bridge ID (BID) fields. […]
IEEE 802.1D Spanning Tree Protocol (STP) and Rapid Spanning Tree Protocol (RSTP) uses the Spanning Tree Algorithm (STA) to decide which switch ports on a network have to be put in blocking state to preventing loops. The Spanning Tree Algorithm designates one switch in the network as the root bridge. The root bridge is considering […]
In the previous article, I have explained the redundancy. It increases the network availability by protecting the network from a single point of failure, such as a fault in a network cable or fault in a switch. When engineers introduce the physical redundancy in design, loops and duplicate frames happen. I have written in the […]
Reliability is a quality of computer network that consistently performs according to its specifications. It has long been considered one of three related attributes that must be considered when planning network. Redundancy is one of the key factors to maintain network reliability. Multiple physical connections between network devices provide redundant network paths. The network can […]
The NAT and private IPv4 addresses have slowed down the depletion of IPv4 addresses but NAT has some disadvantages. The one major benefits providing by NAT is the security. It hides the private IPv4 network from the public Internet which provides a perceived level of security by denying computers on the public Internet from accessing […]
The port forwarding configuration on Cisco routers is similar to the configuration of static NAT. It is a static NAT translation with a specific TCP or UDP port number. The figure above shows an example port forwarding configuration using Cisco IOS commands on router R2, 192.168.11.100is the inside local IPv4 address of the webserver. The […]
Port forwarding is also known as port mapping and tunnelling. It is the method of forwarding traffic destined to a specific network port from one network node to another. The external user can access a specific port on a private IPv4 address inside a LAN from the outside, through a NAT-enabled router. In other words, […]
Port Address Translation (PAT) is also known as NAT overload. Port Address Translation preserve addresses in the inside global address pool. Port Address Translation (PAT) allows the router to use one inside global address for many inside local addresses simultaneously. We can use a single public IPv4 address for hundreds, even thousands of internal private […]
Dynamic NAT maps inside local addresses to inside global addresses automatically. The inside global addresses are usually public IPv4 addresses. Dynamic NAT uses a pool of public IPv4 address or a group public IPv4 addresses for translation. It also requires the configuration of the inside and outside interfaces participating in NAT like Static NAT. The […]
Static NAT is mapped inside and outside addresses one-to-one. It allows external devices to establish a session to internal devices using the statically assigned public address. For example, an internal web server mapped to a specific inside global address. The figure below illustrates the inside network containing a web server with a private IPv4 address […]
