BGP – Transit AS

In the previous blog, we discussed, how to configure weight attribute. Now when I started to prepare the design for the next attribute, I felt that, let’s first clear about transit AS.

By default, eBGP peers share all routes/prefixes with each other. In the above example, considering AS-7090, ISP1 and ISP2 will share all routes with AS-7090. In this situation ISP1 and ISP2 can route the traffic via AS-7090, becoming AS-7090 as a Transit AS.BGP Attributes 2 - Local Preference.001

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BGP Path Attributes 1 – Weight

“WEIGHT” is Cisco Proprietary Attribute and it’s not included in the BGP updates. Weight can be set between 0-65535 (default value is 0) and higher value is more preferable. Weight is used within individual router, means its locally significant. When BGP choosing best path, Weight is considered first above all the other attributes.

BGP router set the weight to 0 on learned routes from peers and 32768 for locally generated routes.

In the below design and configuration output, all routes are configured with minimum configuration and we will focus on INBL and INTERNET routers to understand weight attribute in more detail.

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Cisco ASA FirePOWER (SFR) Quick Start Guide

The ASA FirePOWER module supplies next-generation firewall services, including Next-Generation Intrusion Prevention System (NGIPS), Application Visibility and Control (AVC), URL filtering, and Advanced Malware Protection (AMP).

The ASA FirePOWER module runs a separate application from the ASA. The module can be a hardware module (on the ASA 5585-X only) or a software module (all other models).

As below snapshot shows Packet flow for software module;

Cisco ASA FirePOWER packet Flow

The module has a basic command line interface (CLI) for initial configuration and Read More »

OSPF Adjacency State Machine

Hi All,

The Hello Protocol is responsible for neighbour acquisition, maintenance and for ensuring two way communication between neighbours.

In other words, Hello packets are used to form neighbour/adjacency relationship on OSPF enabled links.

There are 8 STATE process to establish adjacency.

Down

Attempt

Init

2-Way

Exstart

Exchange

Loading

Full

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Cisco Discovery Protocol (CDP)

Cisco Discovery Protocol (CDP) is a Layer 2, media-independent, and network-independent protocol that runs on Cisco devices to learn about directly connected devices.

This protocol facilitates the management of Cisco devices by discovering the directly connected devices, determining how they are configured and allowing systems, using different network-layer protocols, to learn about each other.

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Cisco Multi Gigabit Ethernet Technology / NBase-T Technology and NBase-T Alliance

New wireless standard – 802.11ac supports upto 6.8 Gbps wireless speed.

Mostly cables used between wireless access points and switches are Cat5e, which are limited to 1Gbps speed. Because of this, we cannot get full advantage of  802.11ac (Wave 2) and subsequent technologies without upgrading the cabling infrastructure.

We can see this situation in following diagram.

N-BaseT

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