Domain Name System (DNS) is used to resolve website names (or host-names) example www.testdomain.com into IP addresses 90.1.1.1. This is a useful article to understand How DNS Works? Importance and requirement of DNS Let’s discuss a network issue to understand the importance of DNS. You are a Network Engineer in an organization and a customer […]
Segment Routing (SR) is a new label switching technology that will evolve and enhance the working of IP and MPLS networks. Segment Routing (SR) uses a new and efficient way of routing which is more flexible and scalable compared to legacy MPLS technology. In Segment Routing, the labels are not generated by Label Distribution Protocol […]
OSPFv3 is a link-state protocol for IPv6. A link-state protocol makes its routing decisions based on the states of the links that connect source and destination machines. The state of a link is a description of that interface and its relationship to its neighboring networking devices. The interface information includes the IPv6 prefix of the […]
IPv6 Stateless Autoconfiguration is a capability of a host to automatically acquire an IP address without needing DHCP. It uses its link-local address and the Neighbor Discovery Protocol (NDP) to do this. Each device creates a link-local address for itself based on the prefix FE80:: and the interface MAC address. This address is only valid […]
Eplain 5 EIGRP packets in sequence. Which packets are sent as multicast and which are sent as unicast? What is difference in the output of commands “show ip EIGRP topology” and “show ip EIGRP topology all-links”? What is criteria to become a Feasible Successor? Explain DUAL and RTP algorithms used by EIGRP. What is Stuck […]
In this article, we will discuss the similarities and differences between OSPF and ISIS Protocols. In this article we will compare OSPF and ISIS and discuss their similarities and some key differences between them. There are many similarities between the OSPF and ISIS. Below are few main similarities between both protocols. Both OSPF and ISIS […]
When we try to connect to a remote subnet/prefix from a router (for example, Ping, Telnet, or FTP), following basic routing rules are followed in given order. Select the route with longest mask (subnet mask). Select the route with best Administrative Distance. Select the route with best metric. If equal metric paths/routes exist, perform load […]
MPLS LDP IGP Sync is feature used to avoid traffic blackhole scenarios in the MPLS VPN networks. The traffic blackhole could occur when IGP is running up and fine on a Backbone link but, LDP is down. This could be due to mis-configuration or due some hardware/software bug issues in the network. To avoid such […]
We can change the metric learned by default (hop count) using the Offset-lists in RIP. In above topology, on router R1, we see the route for prefix 192.9.1.5/32 learned via 3 paths, i.e. via R2, R3, and R4 with equal metrics (hop count 2). Important Note: In RIP, Hop count or the Metric gets increased […]
OSPF behaves differently while peers are connected using various kind of networks. Below are the different Network Types: Point to Point Broadcast Non-Broadcast Multi Access (NBMA) Point to Multi-point Broadcast Point to Multipoint Non-Broadcast This article will discuss the details of OSPF Non-Broadcast Multi Access Network. In OSPF Non-Broadcast Multi Access Network, OSPF runs the […]
BGP LOCAL-AS CONCEPT – Command Syntax neighbor x.x.x.x local-as local-AS-numberneighbor peer-group local-as local-AS-number Local-AS cannot be customized for individual peers in a peer group. Local-AS cannot have the local BGP protocol AS number or the AS number of the remote peer. The local-as command is valid only if the peer is a true eBGP peer. […]
Encryption is a method that encodes the data that is unreadable by unintended parties. For example we want to send a text “The wardrobe key is on the kitchen shelf” secretly to another peer. This is clear text information and can be read by the hacker easily. With help of encryption we can encrypt this […]
Route Redistribution in EIGRP: Redistribution is a technique using which the boundary routers connecting different routing domains can exchange and advertise routing information. In this article, we will learn how to redistribute any routing protocol into EIGRP. Below syntax is followed. The command has to be configured in router configuration mode for the Route Redistribution […]
This blog helps you understanding and grasping IPv6 Header Details. IPv6 is the replacement Internet protocol for IPv4. It corrects some of the deficiencies of IPv4 and simplifies the way that addresses are configured and how they are handled by Internet hosts. IPv4 has proven to be robust, easily implemented, and interoperable, and has stood […]