Posts under this category provides an overview of Routing & Switching (OSPF, BGP, STP, RSTP etc ) concepts with detailed explanation. Various practice lab example will be used to demonstrate the concepts.
BGP next hop is a mandatory attribute of BPG which provide information of the next hop for the advertised subnet. iBGP doesn’t change the next hop of advertised subnets. BGP next hop self can help in changing the next hop of advertised subnets in IBGP. Let’s understand the why we need BGP next hop self. … Read more
There are three BGP origin code attribute which are used in path selection. The bgp table can be checked using show ip bgp command We will use the same topology which we have used in our basic BGP configuration post. To learn about the origin codes we will do following: i origin code: A route … Read more
In this post we will learn basic BGP configuration on Cisco IOS router, we will advertise network to the EBGP peers and test connectivity. The post is in continuation of the BGP concepts discussed in previous post. We will use below topology for this basic BGP configuration example. We have two router Router3, Router4. ASN3 … Read more
BGP (border gateway protocol) is a routing protocol used in internet. Entire public subnets are given to various ISPs and allocated with an AS (autonomous system) number. Now these various subnets are interconnected and the job to find out which IP subnet is where and how to reach that subnet is done by BGP. BGP … Read more
TACACS+ can be used to perform the device administration of Cisco IOS device like routers & switches. Using TACACS+ server we can create granular policies on TACACS+ server for different set of users. In this post we will configure Cisco router for TACACS+ authentication the same configuration can be used on a Cisco switch as … Read more
SSH is secure way to access a Cisco router or switch over an IP network. It does encryption of the traffic using RSA key pairs whereas telnet sends the traffic in plain text over network. In case of telnet entered username or password can be seen easily by anyone who is capturing the traffic. We … Read more
There can be certain situation where we may loose access to a Cisco CSR router and due to that we would not be able to login to the device. In such situations we can do password recovery of Cisco router to regain access to the device, by password recovery we will not loose any configuration … Read more