NOGs and other NOGs, they sit on logs... Looking at the Internet from the outside, it might almost seem like it runs just on … [Read more...]

Yet Another Blog About Segment Routing, Part2 : TI-LFA

TI-LFA Fig.7

So I finally got some time after a while to write something. In this post we will be looking at Topology Independent LFA aka … [Read more...]

Dual Stack Routed Access Layer With OSPF Design Guide


The networking industry has been advocating “more layer 3, less layer 2” for years. If you’ve been in the industry for any … [Read more...]

Designing A Multi-Region, Multi-Hub Phase 3 DMVPN With BGP


I recently completed a design and lab scenario that uses Cisco DMVPN as a backup to a primary MPLS WAN (I’m still planning … [Read more...]

Linux Network Interface Configuration With udev


I've recently been running down (or is it through) the Linux, systemd, networkd, udevd rabbit hole at full pelt and thought … [Read more...]

HTIRW: That Big Number Database in the Sky

As we come close to ending this rather long running series on how the Internet really works (because I'm certain you're about … [Read more...]

HTIRW: Internet Exchange Points

Most providers — transit, edge, and content — are pretty obvious to the various users of the Internet. Users interact with … [Read more...]


One of the various problems we face in the data networking world is the absolute plethora of tunneling technologies we have … [Read more...]



In this post we will look at something which is relatively new but not as cool as my previous post on Segment Routing. We … [Read more...]

Yet another blog about Segment Routing-Part 1

Segment Routing Fig.9

In this blog post we will be taking a deeper look at Node/Prefix SID and SR/LDP Interworking. If you work or have an interest … [Read more...]

RFCs You Should Know: 5218


Quite often RFCs in the "earlier days" discussed not only process but also design. Looking back now, considering the … [Read more...]

ISIS Link-Group

ISIS Link-Group

Introduction On the Core or Edge network, we need more and more bandwidth. For a large service provider, in some parts of … [Read more...]

OpenStack Neutron – The Dirty Network Detail

OpenStack Neutron Networking

Update: I'm slowly getting there, third and more accurate diagram attached below which now includes where security policies, … [Read more...]

BGP RR Design – Part 2

BGP RR Fig.10

This is a continuation from Part 1 9. ACME VPN RR's Design: So the current total number of PE's dedicated for VPN … [Read more...]

BGP RR Design – Part 1

BGP RR Fig.12

1. Introduction In this post we will be looking at large scale RR design by using a fictional ISP ACME  as a reference. As … [Read more...]