Tuesday 3 December 2019

Port Mirroring in Junos

So sometimes, the manual isn't quite detailed enough...

At the moment, our telephony people are having some issues with various things like handsets logging themselves out under certain conditions.

Vendor support has requested packet captures, and rather than schlepping around to the four corners of campus, dropping off laptops by each switch stack, I thought "wait, Junos does port mirroring, and it looks straightforward".

It is, and it isn't...

Wednesday 23 October 2019

Glitchy RPKI OV and uRPF: one hell of a match

I've previously written about RPKI and mentioned some of the glitches. It looks like there are some other fun interactions to be had if you're implementing all the "best practice" internet edge routing for your customers...

Tuesday 2 July 2019

One year on, in a different kind of school...

A year ago (to the day), I started what I would seriously consider a "dream job title" - that of Network Architect at a University (at the first place in sub-Saharan Africa to have an Internet connection - so long ago that its first IP address allocation was done within an RFC!). It ticked all my boxes in terms of favourite things to do, and promised to throw me in at the deep end in a much more challenging environment. I didn't have any particular desire to leave my last position (which I enjoyed immensely), but when I got two phone calls some time apart strongly suggesting I ought to apply for the position, and with an interesting list of "things we need done", after much hand-wringing, I jumped at the chance, and made it through the selection process. #GreatSuccess.


Securing Internet Routing: RPKI OV and ROAs

For some time now, I've had a ticket in my queue to "Investigate RPKI". A few weeks ago, we experienced some strange internet outages that turned out to be because not all is well with RPKI Origin Validation at one of our upstream ISPs...

Friday 10 May 2019

On the State of Firewalls: are NGFWs (becoming) obsolete?

Between the last blog post and this one, I’ve moved from K-12 into Higher Education, at the first place in Sub-Saharan Africa to have Internet connectivity. This is a vastly different environment in some ways – in particular, firewalling is quite different. You’re dealing with a user population that is entirely adults. Some of those adults engage in legitimate research on things that some would consider a bad idea (malware) or “morally dubious” (porn, pop-up ads, etc.), or needs unfiltered traffic (network telescopes, honeypots, big data “science DMZs” ). The particular University I work at has generally had a liberal outlook with regards to personal freedoms (and concomitant responsibility) – I think that’s generally a good thing and exactly where higher education should be.

We’re currently looking at doing a hardware refresh of our ~7 year old enterprise firewalls – mainly because the support on the current solutions is eye-watering. The present solution works fine (although it has quite limited capacity for logging – about 8 hours of our traffic), and it’s approaching vendor EoL status. Interestingly, even moving to a newer (and, because Moore’s law, more performant) hardware platform from the same vendor saves us money over a number of years. So we’re thinking about what we need, and that’s prompted some musings about the state of firewalls…