Author: upravnik

Each network card has a unique identifier called a Media Access Control (MAC) address. This address is used in LANs for communication between devices on the same network segment. Devices that want to communicate need to know each other MAC Read More …

Layer 2 switching (or Data Link layer switching) is the process of using devices’ MAC addresses to decide where to forward frames. Switches and bridges are used for Layer 2 switching. They break up one large collision domain into multiple smaller Read More …

The following table lists the differences between the three most popular interior routing protocols:   Feature RIP EIGRP OSPF Type distance vector hybrid distance vector Metric hop count bandwidth and delay cost Speed of convergence slow fast fast Routing classful Read More …

The following table lists the differences between OSPF and EIGRP:

Here is a list of the most important OSPF features: link state routing protocol classless routing protocol supports VLSM (Variable Length Subnet Mask) converges fast uses the concept of areas uses multicast address for routing updates (224.0.0.5 and 224.0.0.6) sends Read More …

Route summarization helps reduce OSPF traffic and route computation. OSPF, unlike EIGRP, doesn’t support automatic summarization. Also, unlike EIGRP, where you can summarize routes on every router in an EIGRP network, OSFP can summarize routes only on ABRs and ASBRs. Read More …

OSPF can be configured to authenticate every OSPF message. This is usually done to prevent a rogue router from injecting false routing information and therefore causing a Denial-of-Service attack. Two types of authentication can be used: 1.    clear text authentication Read More …

Based on the network type, OSPF router can elect one router to be a Designated Ruter (DR) and one router to be a Backup Designated Router (BDR). For example, on multiaccess broadcast networks (such as LANs) routers defaults to elect Read More …

Configuring OSPF 1 OSPF basic configuration is very simple. Just like with other routing protocols covered so far (RIP, EIGRP) first you need to enable OSPF on a router. This is done by using the router ospf PROCESS-ID global configuration Read More …

OSPF (Open Shortest Path First) is a link state routing protocol. Because it is an open standard, it is implemented by a variety of network vendors. OSPF will run on most routers that doesn’t necessarily have to be Cisco routers Read More …