Work on rob.sh

Lessons from Career Coaching

Mon, 27 Nov 2023 11:27:01 +0000

In the autumn of 2022, I got an opportunity to attend an external leadership course. One of the things that it involved was some coaching sessions. I didn’t really think that talking to someone about work was something that I needed (and honestly probably didn’t understand what a coach did…), but engaged with it anyway.

Cue the start of 2023 — Google went through some big changes, and unfortunately, my health took another downturn. At the same time, I was personally struggling with balancing the work that I was doing leading a wider technical team (especially with layoffs impacting their direct management), driving an innovation project (which I was mostly doing out of hours), and keeping myself healthy.

OpenConfig Interfaces - Some Examples

Tue, 08 Sep 2015 23:23:00 +0000

I’ve talked a little on this site before about what we’re trying to achieve with OpenConfig. However, one of the observations that it’s easy to make is that YANG models alone don’t really achieve anything in terms of making the network more programmable. To make the network more programmable, we need to have tooling that helps us create instances of those modules, manipulate them, and then serialise the into a format that can be used to transmit data that conforms to the model to a device.

The right tool for the job: Choosing where to use RSVP-TE or SR.

Mon, 01 Jun 2015 22:45:00 +0000

I noted that at NANOG64 this week in San Francisco, there are talks (both from Juniper) about both SPRING/Segment Routing and RSVP-TE. These are both protocols/technology approaches (since one can’t really call SR a protocol) that I’ve been involved in the evolution of over the last few years. A question that I’ve been asked more times than I’d like is why we chose to look at a new approach (SR) rather than go with a technology that exists RSVP-TE.

SPRING Forward(ing)

Wed, 29 Jan 2014 08:00:00 +0000

I recently gave a talk at UKNOF relating to Segment Routing/SPRING and the operational challenges that we are trying to resolve through it. You can see it on YouTube below - or the slides are on this site - SPRING Forward(ing) - UKNOF27

Almost Two Years On: Where is SDN?

Sat, 10 Aug 2013 06:47:17 +0000

Almost two years ago I wrote a post on this site entitled Some Initial Thoughts on the SDN. Clearly, since then the SDN concept gained some more legs (and entered a new stage of the hype cycle) - so, where are we right now?

Firstly, I think its fair to say that the concept presented by Scott Shenker of having a single centralised computational element controlling COTS OpenFlow-speaking switches has fallen out of favour somewhat (based on the discussions with other network architects, engineers, and implementors that I have had). Somewhat as predicted, there are real challenges with this approach within high-scale, distributed networks:

Reinforcing the Kitchen Sink - Another BGP Presentation

Sat, 08 Oct 2011 19:48:08 +0000

On Friday, I presented at the Netnod meeting in Stockholm, Sweden - again about BGP error handling - this time presenting a bit of an update as to why this continues to be a problem for the Internet (and private BGP deployments) - and why this work is still really relevant. In addition, I tried to give an overview of what the solution space looks like. I’m not sure whether there’s video, but as usual, the slides are linked below!

LINX71 - 100GE in the Lab

Thu, 23 Dec 2010 16:32:57 +0000

I spoke at LINX71 about the testing that we (C&W) have been doing in the lab with 100GigE - we got a pre-production card and hence had a look at the technology for real. Thanks to LINX, the presentation video can be seen by clicking on the image below.

Once again, however, whatever LINX use as a presentation laptop didn't render my slides properly - even though I'd submitted PDF too! Hence the slides can be found on this site.

BGP Error Handling and Enhancements Post IETF-79

Sun, 14 Nov 2010 22:41:46 +0000

With IETF 79 happening last week - I think one of the great things that's coming out of the IDR work leading up to the meeting has been that quite a few drafts have been written around the requirements that exist in BGP for better error handling. I've been vocal about this before, of course, so it's not that surprising that I'm (yet again) banging the drum for this cause, however, we are getting somewhere finally. To that end, I was wanting to air some views on a couple of the drafts that either have benefits to the operational community, or don't quite hit the mark.

UKNOF 16 - Enhancing BGP - Video

Mon, 05 Jul 2010 22:45:18 +0000

Tom Bird of PortFast and Brandon Butterworth of Bogons do a great job of webcasting, and recording UKNOF video. Thanks to them, the video of the presentation I gave at UKNOF16 can be watched here. Or you can download it by clicking the image below!

As always, thoughts/comments/corrections most welcome!

This is also probably a good time to mention that my new work mail address is rob.shakir (at) cw.com

Leaving AS5413

Sat, 19 Jun 2010 10:45:23 +0000

For information, and because it means that I have revoked a bunch of UIDs from my GPG Key I am no longer working at AS5413 (Vialtus, Daisy, GX Networks etc.) as of June 18th, 2010. It's been a good two years, but the company direction no longer co-incides with the direction in which I would like to go. I've enjoyed the projects I've worked on, been in contact with a lot of great people, and learnt a lot!

UKNOF 16: Enhancing BGP

Mon, 26 Apr 2010 11:12:10 +0000

After a late programme committee request, I presented on “Enhancing BGP” at UKNOF 16. The presentation was intended to be an update on the current drafts in the IDR working group, and give some encouragement to operators to get involved, and contribute.

I’ll put the video up when the Tom at PortFast and Brandon of Bogons have done their excellent job on it. For the meantime, the slides are linked below.

There's also a good add-paths presentation that John Scudder and Dave Ward gave at NANOG here

Error Handling in BGP (Again!)

Wed, 21 Apr 2010 14:04:33 +0000

It looks like, once again, there's another attribute flying around the global BGP table causing Quagga instances to crash (if based on 0.99.9 - I believe the bug is fixed in 0.99.10). This relates to the 2007 draft that introduced AS_PATHLIMIT - see ietf.org - draft-ietf-idr-as-pathlimit. This attribute is actually relatively interesting, from an operator's point of view, where control that is more granular than setting the common no-export or no-advertise communities does not suffice.

CV Update

Tue, 09 Feb 2010 20:52:19 +0000

I am currently actively interested in new opportunities due to changing circumstances with my current role. I’ve therefore uploaded a current curriculum vitae to this site.

Network Updates and Opportunities

Sat, 12 Dec 2009 12:06:52 +0000

A quick personal post to break the silence here!

I’m currently very interested in hearing about any UK or EU-based network engineering or architecture opportunities that are out there, especially in SP networks that run MPLS with TE. If anyone has some such opportunity, or knows of something that they think might suit me – please drop me a mail to rjs@rob.sh for a copy of my CV.

An outline of my CV is available on LinkedIn.

I’m hoping to find some time to put some technical articles together that can be posted here in the near future.

LINX 65 Presentation

Mon, 15 Jun 2009 00:01:49 +0000

Further to my previous post - I presented this issue at LINX65 - video and slides can be found below.

Video
Fixed Slides - LINX’s PowerPoint install seems to have corrupted my slides on the day.

Comments and feedback are most welcome.

Removing BGP from a VRF under 12.2(33)SRC2

Fri, 24 Oct 2008 17:04:59 +0000

I had a bit of a weird problem last night – when trying to remove BGP from a VRF on a 7600 running 12.2(33)SRC2, I tried:


ar01.tn5(config)#router bgp 65302
ar01.tn5(config-router)#no address-family ipv4 vrf SRC2-TEST
ar01.tn5(config-router)#exit
ar01.tn5(config)#exit

One would expect that this would stop BGP redistributing the VRF routes for the VRF SRC2-TEST. In fact, what happens is that the VRF starts reporting ‘debugging-style’ messages:


ar01.tn5#sh run vrf SRC2-TEST
Building configuration...

% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
% BGP context has not been initialized properly.
% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
% BGP context not been initialized properly.
% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
% Topology SRC2-TEST::VPNv4 Unicast::base is currently being deconfigured.
Current configuration : 340 bytes
ip vrf SRC2-TEST
 description :c=CORE:x=rjs test for ar01.tn5 issues:
 rd 5413:1020
 export map EXPORT-MAP-SRC2-TEST
 route-target export 5413:1020
 route-target import 5413:1022
!
!
ip route vrf SRC2-TEST 10.0.0.0 255.255.255.0 Null0
!
router bgp 65302
 !
 address-family ipv4 vrf SRC2-TEST
  redistribute static
 exit-address-family
end

And you then can’t get rid of the BGP from the VRF. It turns out the fix for this is to remove the VRF itself – or, rather than removing the address-family itself, remove the contents of the address family. I’m not entirely sure that this is designed behaviour – and I couldn’t seem to find any further results for it. I guess it needs to be put into TAC as another Cisco weird.

Building the RIPEDB server

Wed, 08 Oct 2008 12:03:52 +0000

It took me a few hours over the course of this week to build the RIPE whois server for some internal projects – given that there seems to be a very limited amount of documentation for the build process, and threads on mailing lists, I’m going to post this here. I hope that it gets picked up by Google.

The first problem that is encountered is that the libtool that is included with the whois server does not support ‘modern’ tags, such as –tag=CC. This looks to be because the included libtool is somewhat dated. This can be easily fixed by using the system libtool:

Handy vim tip

Fri, 01 Aug 2008 16:48:00 +0000

I’ve been working on a number of bits of code recently, and have found that it’s not entirely practical to check into RCS or SVN for every change that I’ve made. I really like to work by committing when I’ve finished adding a feature to a script, or a project. Hence, I’ve been using the vim “set backup” option. However, this has some limitations, and hence I decided to have a look at what .vimrc could do for me.

Django

Sat, 01 Mar 2008 21:11:42 +0000

Since I’ve got a few moments, and I’ve decided to actually write down some rants rather than deciding that I can’t be bothered to - I’m going to use some space to single the praises of Django.

I’ve been using Django for a couple of years now - since around the autumn of 2005, and as such, feel that I’ve got a pretty good grasp of how the framework works. I haven’t really hacked around that much with the innards of Django (although I did propose a patch), however, what I really like about this framework isn’t particularly the internals, but just the whole philosophy that there seems to be in terms of building a web application.