Five selfish reasons to interview candidates

Lets be honest. It is hard to justify the time needed to interview people. It can be really hard to motivate yourself to interview potential new hires when project deadlines are looming. It is perfectly fair to ask yourself, “what’s in it for me?” I think there is a payoff for time spent on hiring. […]

Author information

John Harrington

John is an experienced data center engineer with a background in mobile telecoms. He works as a network test engineer for a large cloud service provider, and is gradually accepting that he's a nerd. He blogs about network technology and careers at theNetworkSherpa.com. You can reach him on twitter at: @networksherpa

The post Five selfish reasons to interview candidates appeared first on Packet Pushers Podcast and was written by John Harrington.

NFD6 Preview: Solarwinds

NFD6 Preview: Solarwinds

Finding a New Path (Part 1)

In my last installment on the topic of fast convergence, I said I’d be discussing the calculation stage of fast convergence next. Orhan tried to scoop me in the comments, but that’s okay –I’m working at this through the process switched path, rather than interrupt context. In parallel with flooding information about the topology change […]

Author information

Russ White

Principle Engineer at Ericsson

Russ White is a Network Architect who's scribbled a basket of books, penned a plethora of patents, written a raft of RFCs, taught a trencher of classes, and done a lot of other stuff you either already know about, or don't really care about. You want numbers and letters? Okay: CCIE 2635, CCDE 2007:001, CCAr, BSIT, MSIT (Network Design & Architecture, Capella University), MACM (Biblical Literature, Shepherds Theological Seminary). Russ is a Principal Engineer in the IPOS Team at Ericsson, where he works on lots of different stuff, serves on the Routing Area Directorate at the IETF, and is a cochair of the Internet Society Advisory Council. Russ will be speaking in November at the Ericsson Technology Day. he recently published The Art of Network Architecture, is currently working on a new book in the area Continue reading

Show 161 – VMware NSX – Real World SDN – Sponsored

Deep diving on VMware NSX ? You bet. Download the PDF file and read along with us as we unpack how VMware NSX works with Brad Hedlund and Scott Lowe. Network Virtualization is the certainly the biggest architecture shift in our careers and probably yours.  And make no mistake, this is about networking.  Greg Ferro often says that […]

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

TwitterFacebookGoogle+

The post Show 161 – VMware NSX – Real World SDN – Sponsored appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Need more capacity: MPC4e cards are there!

Need more capacity: MPC4e cards are there!

Need more capacity: MPC4e cards are there!

How bad is the OSPF vulnerability exposed by Black Hat?

I was asked a few weeks ago by our field engineers to provide a fix for the OSPF vulnerability exposed by Black Hat last month. Prima facie there appeared nothing new in this attack as everyone knows that OSPF (or ISIS) networks can be brought down by insider attacks. This isnt the first time that OSPF vulnerability has been announced at Black Hat. Way back in 2011 Gabi  Nakibly, the researcher at Israel’s Electronic Warfare Research and Simulation Center, had demonstrated how OSPF could be brought down using insider attacks.  Folks were not impressed, as anybody who had access to one of the routers could launch attacks on the routing infrastructure. So it was with certain skepticism that i started looking at yet another OSPF vulnerability exposed by Gabi, again at Black Hat. Its only when i started delving deep into the attack vector that the real scale of the attack dawned on me. This attack evades OSPF’s natural fight back mechanism against malacious LSAs which makes it a bit more insidious than the other attacks reported so far.

I exchanged a few emails with Gabi when i heard about his latest exposé. I wanted to understand how this attack Continue reading

Plumbing OpenBSD Software with gdb(1)

This post is about finding and fixing a memory leak I discovered in the SNMP daemon, snmpd(8), in OpenBSD. This sort of analysis is foreign territory for me; I’m not a software hacker by day. However, using instructions written by Otto Moerbeek as my Rosetta stone and Google to fill in the blanks when it came to usage of the GNU debugger, gdb(1), I was able to find and fix the memory leak.

I’m documenting the steps I used for my future self and for others.

The Problem

When walking the pfTblAddrTable in the OPENBSD-PF-MIB, the unprivileged snmpd process would grow in terms of SIZE and RES. Querying other parts of PF-MIB or other MIBS altogether resulted in no memory usage increase.

Since I knew roughly which code path must have the leak, I first examined it manually. I could not see where memory wasn’t being given back. I needed to instrument the process as it was running in order to find the leak.

Before Starting

This set of instructions from Otto Moerbeek was my guide. As per his guide, you have to rebuild libc with MALLOC_STATS enabled. This enables statistics collection that is used later on.

Edit /usr/src/lib/libc/stdlib/malloc. Continue reading

Plumbing OpenBSD Software with gdb(1)

This post is about finding and fixing a memory leak I discovered in the SNMP daemon, snmpd(8), in OpenBSD. This sort of analysis is foreign territory for me; I'm not a software hacker by day. However, using instructions written by Otto Moerbeek as my Rosetta stone and Google to fill in the blanks when it came to usage of the GNU debugger, gdb(1), I was able to find and fix the memory leak.

I'm documenting the steps I used for my future self and for others.

NFD6 Vendor Preview: Nuage Networks

NFD6 Vendor Preview: Nuage Networks

Professional Loneliness

Lately I’ve been bouncing some generic DMVPN questions off the twittersphere.  I’ve used DMVPN sporadically in tiny single-use cases before, but now I am planning to roll out a somewhat larger implementation with a dual cloud and dual hub, complicated by the fact that I don’t control the perimeter router at our DC and I […]

Author information

Matthew Mengel

Matthew was a Senior Network Engineer for a regional educational institution in Australia for over 15 years, working with Cisco equipment across many different product areas. However, in April 2011 he resigned, took seven months of long service leave to de-stress and re-boot before becoming a network engineer for a medium sized non-profit organisation. At the end of 2013, he left full-time networking behind after winning a scholarship to study for a PhD in astrophysics. He is on twitter infrequently as @mengelm.

The post Professional Loneliness appeared first on Packet Pushers Podcast and was written by Matthew Mengel.

Don’t Need No Stinking Underlays

Why’s everyone complaining about overlays; it’s the underlays that are the problem. I’ve been in this awful game for years, I’m tellin ya, me and the dinosaurs were buddies back in the medieval donkey days – so listen up losers, I’m diatribin from experience. That Greg Ferrous, he’s a wise fella; almost like a father to me […]

Author information

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

TwitterLinkedIn

The post Don’t Need No Stinking Underlays appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Exploring OSPF Messages Between New Neighbors

A basic network is setup and OSPF is configured.  R1 is then prevented from forming an OSPF adjacency with R2 due to R1’s serial interface being configured as a passive interface.

Only Hello packets are seen from R2.

From this Wireshark output we can see:

1. OSPF Version 2 is utilized
2. This is a Hello packet
3. The Hello packet is sourced from a router with OSPF Router ID 2.2.2.2.  Duplicate RIDs will prevent an OSPF adjacency and cause other issues.
4. The interface that sourced this Hello packet resides in OSPF area 0.  This item is used to verify that the two connected router interfaces are within the same OSPF area – this is a requirement in order to form an OSPF adjacency.
5. No authentication is used
6. A /30 network mask is used on R2’s connected interface.  This item is used to verify that the two connected router interfaces are using the same subnet mask, which is a requirement in order to form an OSPF adjacency in addition to the two interfaces being within the same primary subnet.
7. Hello and Dead timers.  These must be the same on both connected routers in order to Continue reading

MrsJanitor’s Aus-Some Tour of SFO / SJC

Well I just got my itinerary for my trip to Sunnyvale for the Juniper Ambassador’s Summit in October and my wife and I have decided to spend an extra couple of days either side to get out and see the sites. We will be arriving in San Francisco at 11am Sat 5th of October and flying out around 11pm on Friday 12th, and we are looking to fill our schedule!

This is my wife’s first trip to the US, and I know she wants to get out and about and see things (also probably while Im in conference too). I know her list includes seeing the Golden Gate Bridge and Alcatraz… oh… and… “The Full House House”.

Thankfully we have the company of two of my good friends who are locals – Ashton (from Juniper) and my old work mate Cooper Lees, and we are working out “what we should see”.

So what do you consider “must see” things in this area? Let me know in the comments and we will see what we can fit in.

Also, while we’re in town, I would love to catch up with any locals in the area for drinks/coffee/food etc so Continue reading

The Priorities Bill of Rights – 10 practical steps to managing group priorities

Managers everywhere are abusing their employees by using priorities to convey to-do lists. It is not because of anything insidious in their objectives, but the average manager (both low- and high-level, by the way) simply doesn’t think enough about priorities to really do anything meaningful with them. For teams I lead, our entire existence revolves […]

Author information

Michael Bushong

The post The Priorities Bill of Rights – 10 practical steps to managing group priorities appeared first on Packet Pushers Podcast and was written by Michael Bushong.

[Overlay Networking] Part 3 – The Underlay

NFD6 Vendor Preview: Big Switch