Tales of Shmoocon 2012: Joining Labs and Building the Network

I have been going to DEFCON for three years now with a group of fellow hackers from my town. Some of them went to Shmoocon last year and reported that I should definitely come down for 2012. So, with all possible insanity in mind, four of us jumped in a car and drove 10 hours through the night to the con.

Because one of my group had signed up for this thing called “Labs,” we arrived at 6am and a day early. I found out the details that morning about how labs was a pre-registered thing that I hadn’t heard about in time and then I napped until just after 9.

Now, I’ve been to DC many times. Given the choice between wandering the city again and doing something exciting surrounding the con, I went for the con. I had made it a habit to get into guest-listed parties I didn’t know about until too late while at DEFCON and have made it a personal point of pride to keep up the habit every year. So, in a move that I’m sure you won’t be able to do next year after this is published, I strolled into the labs area at 9:30, sat down at the management network / core table, and became part of the team… which happened to include my friend and another local who I didn’t expect. Maine was very well represented.

Labs Begins

Labs is split up into several teams and I’m sure there was some consensus as to how this should be apportioned before I arrived. Each team had their own table around the edge of the room with the routing, switching, and firewall (“network”) group at a table in the middle.

At the start of the day, my new group talked about the services we wanted to roll out. We talked about monitoring, so I took a stake in deploying Nagios. We went around the table and called off IP addresses in order to assign to our machines and started hacking away.

Immediately I hit the same snag as everybody else. We didn’t have internet on our little network. We couldn’t look anything up, and even more critical we couldn’t install any software packages that weren’t on a disc already. Everything had to wait until we could get online, so I grabbed a long cable, some gaffer’s tape, and walked to the network group to ask for a VLAN to the Internet. I gave it a quick test before we plugged into the switch and my laptop suddenly pulling 100mbit to the whole world. We quickly throttled that down to the level we had paid for and with that I plugged in the the management network. It wasn’t the final solution — I knew we had to later change to a real switch and establish proper presence on the network, but it was the right-now solution that got us to work.

Building it Proper

Having spent some time preaching the ideas behind Puppet and loathing the Nagios config files, I made the decision to do all my Nagios setup with Puppet. The idea paid off very well. Machines were setup as Puppet clients and then I basically never touched them. From modifying the master configuration, a basic configuration was typed out that pushed my favorite utility packages (ntp, vim, etc) and registered the system with the Nagios server. I ate my own dog food and I loved it.

Where we orientally started tempting all our services on one server, we would deploy them to several respective machines by the end of the day. With a VM server established after lunch, machines were appropriated for different tasks. As our needs for machines changed, we found it easiest to just keep the same original starting image and use Puppet to push to them. First up was the LDAP server coming online. I dumped the configuration and certificate files from the LDAP system into Puppet and spent a few iterations testing it out, then moved it from the test machine’s config to the general template and it was live. When it caused problems on a machine that was cutoff for a while by firewall rules, I was able to carve out an if/else statement in the configuration template and exempt the system. When the internal DNS server came up, I pushed the new resolv.conf to everything.

Things broke too. They broke a lot, and sometimes we knew they’d break even before they did. It wasn’t a surprise when our team lost internet for a while when we moved to our “real” switch with the proper trunk configs. Things broke when Splunk chewed up the resources of the VM it was on and had to be moved somewhere with more power. They broke when the firewall started destroying every SSL connection after a few packets… and I mean every one on every port across every VLAN and the Internet, and only SSL — and only after negotiation. We scratched our heads when one VLAN on our DHCP server went stupid and couldn’t hear packets that were sent to it, and then we scratched our heads more when changing that machine’s routing table ended up working as a ghost fix for the problem. That was a real stumper because it was affecting inbound packets, but it was the answer that made it happen.

Almost Perfect

On the whole, things were fantastic. We broke off our own bits of the work and started in. Everybody picked off a section of work, everybody worked together helping with other people’s problems, and everybody lived the spirit of things. We could have done a better job of knocking out dependencies like the early internet connection, or getting everybody using a ticketing system right from the start to handle requests between different pieces of software. I’m surprised the firewall crew didn’t want blood by the end of the day with the number of adjustments they had to make between all the different teams and problems they encountered. We did everything verbally with them.

Yet, I think Labs shouldn’t be “quite there” any year for good reason. Labs is about experimenting and pushing the edge. Sure, we may tackle those tidbits next year, but it was about more than just a network. It was seeing 50 people in a room with only the basic managerial structure of, “You’re in this group,” do something big in a day. It was about experimenting. Our central logging was good practice, but it was also learning for at least six different folks that we pushed our logs out to for analysis and learning. It was about cracking jokes over an AirTunes box that was accidentally broadcasting the management network over open Wifi and being impressed at the wireless folks who were running the tools to detect those things.

I’ve done consulting for a while and I’ve seen a lot of networks over the years. In a days time, we shined and we built it right. I heard stories, I shared stories, I saw some impressive setups from garage leftovers and vendor diamonds, and I hacked until I was too tired to keep going.

… But Perfect!

I’ve built my own networks to play on, I’ve worked in lab setups that have their own dedicated 100 rack server rooms, I’ve built a lab network with over 125 machines, but I’ve never had as much fun or been as part of a smooth team as these 50 folks who work together only for a weekend. So, if they don’t give me grief for gaming the system to get in this year, I’ll be applying and attending next time.

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