Basic IPv6 configuration for Nokia and Juniper routers

This is a quick IPv6 interface configuration tutorial for Nokia 7750 VSR (SROS) and Juniper vMX routers.

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BGP Route Reflection diagram

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I had plans to cover Nokia (Alcatel-Lucent) BGP Route Reflectors (BGP RR) in a full-featured post, but… But a lot of new stuff suddenly hit me as I joined Nuage Networks team.

Ok, lyrics aside, during my preparation for BGP exam I noticed that BGP route reflectors behavior defined throughout several chapters and there was no summary diagram (or cheatlist) that covered route reflectors decisions and actions. So, here you are:

This diagram shows the complete decision path of a BGP RR when it needs to reflect a route, including action items for different kind of neighbors (Non-client, Client, regular peer).

Note, that Nokia’s (Alcatel-Lucent) definitions were used for RIB structures (RIB-In, RIB-Out), though the decisions that RR has to make should no differ between vendors.

Download high-resolution file.

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STP/RSTP election process

Just a quick reminder on STP election process (thanks to Dmitry Figol):

  1. Choose Root bridge:
    1. lowest Bridge ID (priority + system mac)
    2. all ports on a Root bridge are designated
  2. Choose Root port on each non-root bridge:
    1. lowest path cost to the root
    2. lowest neighbor Bridge ID
    3. lowest neighbor’s Port ID (port priority + internal port number)
    4. lowest local Port ID (port priority + internal port number)
  3. Choose Designated port on each segment.
    1. bridge with the lowest root path cost
    2. bridge with the lowest Bridge ID
    3. interface with the lowest Port ID
  4. All other ports are non-designated/blocking

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DNS Terminology

https://tools.ietf.org/html/rfc7719 #

The DNS is defined in literally dozens of different RFCs. The terminology used by implementers and developers of DNS protocols, and by operators of DNS systems, has sometimes changed in the decades since the DNS was first defined. This document gives current definitions for many of the terms used in the DNS in a single document.

I saw this RFC has just been published and decided to save it here for further reference since DNS was always a mine field for me.

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Basic L3VPN (BGP/MPLS VPN or VPRN) configuration. Nokia (Alcatel-Lucent) & Juniper

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This time I will cover in details basic Layer 3 VPN (L3VPN or VPRN) configuration, and I decided to kill two birds with one stone by inviting Juniper vMX (read here on how to add vMX to Unetlab) to our cozy Alcatel-Lucent environment.

In this post we will configure BGP/MPLS VPN [RFC 4364] including:

  • PE-PE relationship configuration with VPN IPv4 family introduction
  • PE-CE routing configuration with both BGP and OSPF as routing protocols
  • Export policy configuration for advertising VPN routes on PE routers
  • AS override configuration
  • and many more

As a bonus track I will share with you Control Plane and Data Plane evaluation diagrams which help a lot for understanding the whole BGP VPN picture. Take your seats, there is no flying from VPNs!

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Nokia (Alcatel-Lucent) BGP configuration tutorial. Part 2 – BGP policies. Community

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In the first part of this BGP tutorial we prepared the ground by configuring eBGP/iBGP peering. We did a good job overall, yet plain BGP peering relationship is useless, the power of BGP in its ability for granular management of multiple routes from multiple sources. And the tools that help BGP to handle this complex task are BGP policies at their full glory.

In this part we will discuss and practice:

  • BGP export/import policies for route advertisement/filtering;
  • BGP communities operations;
  • Aggregation of BGP routes: route summarization technique and the corresponding aggregate  and atomic-aggregate path attributes

Index

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Nokia (Alcatel-Lucent) BGP configuration tutorial. Part 1 – basic eBGP, iBGP

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When we say Service Provider, we imply BGP and when we say BGP, we imply Service Provider. There is no way I would leave you without covering configuration steps for one of the most versatile, scalable and robust internet protocols also known as BGP. And here it is – BGP configuration guide for Alcatel-Lucent Service Routers. As with OSPF configuration tutorial I will cover configuration process for various BGP scenarios along with verification and troubleshooting steps bundled with colorful figures, detailed code snippets and useful remarks.

BGP is so huge that I had no option but to write about it in several parts:

Part 1 dedicated to basic eBGP/iBGP configuration. We will practice with common BGP configuration procedures at first, then learn how to export routes into BGP process and prevent unnecessary route reflection by means of split-horizon over eBGP links. After that we will see how to configure iBGP to spread eBGP learned routes across Autonomous Systems. I will cover the necessity of full-mesh iBGP topology and the use of the  next-hop-self  command for iBGP peers.

It’s perfect time to configure some BGP, right?

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Nokia (Alcatel-Lucent) OSPF configuration tutorial

The purpose of this post is to cover basic OSPF configuration steps and commands. Intended readers are engineers with basic OSPF knowledge who want to know how to configure OSPF on Alcatel-Lucent Service Routers (7750-SR, 7705-SR, 7210-SR). All the examples are valid for TiMOS-B-12.0.R8 both/i386 ALCATEL SR 7750 Copyright (c) 2000-2015 Alcatel-Lucent.  software.

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OSPF. Neighbors on a “point-to-broadcast” network

When it comes to basic OSPF troubleshooting the first-aid kit is Neighbor states and things, that should match to form an adjacency. And on one early morning while refreshing my memory on OSPF neighbor states I accidentally ran into quite interesting problem.

But before we start, answer the short question:

Will adjacency be formed between directly connected via Gig. Ethernet interfaces routers R1 and R2 if

  • R1’s OSPF interface type configured as point-to-point
  • R2’s OSPF interface type configured as broadcast

 Time’s up. The answer is – yes and no. Wanna know why? Jump in, I have to show you something.

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LDP. Ordered Label Distribution Control explained

Major network vendors (except Cisco) default to the following modes of Label Distribution Protocol (LDP) operation (as per RFC 5036 LDP Specification):

  • Label Distribution (Advertisement): Downstream Unsolicited (section 2.6.3)
  • Label Control: Ordered (section 2.6.1)
  • Label Retention: Liberal (section 2.6.2)

This topic focuses on Ordered Label Distribution Control procedure to help you better understand when LSR actually assigns labels and initiates transmission of a label mapping.

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