Sunday, March 24, 2013

A tale of two routers

One of the things I want to set up at the office to preserve precious Internet bandwidth is a general proxy/firewall box. This would sit between our current infrastructure and the Internet and do firewall-y type things plus provide VPN connectivity. We have an ancient Cisco that is providing VPN connectivity but it requires a proprietary client that is hard to come by unless you have a Cisco support contract, which isn't available for this antique. Given that I have plenty of fairly recent vintage surplus server equipment hanging around plus a few quad-port Ethernet cards it seemed to me to be a no-brainer to slap the cards into a spare server and toss Linux on it and run with that as the router.

The problem, of course, is time and complexity. I know how to use iptables. I know how to set up things like squid and openvpn and dhcp and so forth. But I really don't want to. I really, REALLY don't want to. I have better things to do with my life. So I went out to find general-purpose router distributions that would do all that hard work for me. Given the equipment available to me (mostly Nehalems with 2.4ghz quad-core processors and 6gb of RAM, modest by the standards of modern compute engines, but way more system than our border router needs), I didn't need to settle for one of the tiny little distributions that are intended to fit on flash memory chips on tiny embedded systems. I could put a full-fledged Linux on there. After some research, I settled on two distributions that are based on a stable core distribution: ClearOS, which is based on Centos 6, and Zentyal, which is based on Ubuntu 12.04 LTS. I know how to manage both Centos and Ubuntu since I've used them in production for years, so if all else failed I could take the starting point that the GUI configurator gave me and fix it to work.

Before doing this at the office I had to of course do a proof of concept. And the perfect proof of concept was my home network, which has five PC's and five devices on it as well as the wireless access point and the managed switch both of which have their own addresses. So I grabbed a decommissioned box that had some pretty hefty stats (Core I7-950 with 12gb of RAM) but no drives (since I'd moved the drives to the big file server box), found a pair of 2.5" drives to fit in its front-loading slot to swap out ClearOS and Zentyal, and set to installing.

I'd been playing with Zentyal for a while at work, seeing if I could make sense of whether it would replace our ancient Windows 2003 domain controllers, and so I started with ClearOS. It slid onto my server just fine, locating my expensive 4 port Intel NIC card and the on-board Intel NIC. I configured it to provide separate networks for my wireless and wired networks (so I could monitor what was happening on the wireless network specifically), and route all traffic out the cable modem connection. All was well. I played with the proxy server settings. That worked pretty well, with the bizarre exception that I can't figure out how to make the automatic proxy settings work, I enabled the Apache server and created the correct wpad file and I see Chrome using it in the Apache server logs but Chrome isn't doing applying the settings for some reason. Okay, something to check out on Zentyal when I do it. I then configured OpenVPN and installed OpenVPN clients on my Android and iPad (I already know OpenVPN works on Windows, Linux, and Mac, duh). My first couple of attempts to connect from my Android didn't work and I was baffled. Finally I clicked on the firewall module and noticed no rule had been created to allow OpenVPN connections when I configured OpenVPN. Point, click, allow, and all works well. iPad worked fine too once I got the certificates on there, which required using iTunes (bleh!) but at that point the iPad OpenVPN software was up and going. And finally I got the mail relay up and going, which forwards all outbound smtp traffic to my mail server in the proto-cloud which then forwards it onwards. Again there were some interesting limitations -- I see no place to set the name and password to authenticate with the remote smartmail server, for example -- but that's easy enough to fix by hand.

Okay, so there's a couple of small glitches but things pretty much were going smoothly with ClearOS. The main issues I ran into with ClearOS were between my ears, i.e., I didn't RTFM and forgot to set up things that needed setting up or set them up incorrectly. So next I shut down the ClearOS system, slid out its drive, slid the new drive in, and installed Zentyal. That, on the other hand... that was pretty much a disaster. It crashed halfway through the setup wizard. It crashed after it updated. It crashed trying to set up the mail relay. The OpenVPN functionality worked but the user interface left a lot to be desired. I noticed that it'd set my domain to a domain and set it back to my own domain, and that pretty much was all she wrote -- it wiped out my VPN, it wiped out the user LDAP directory, and put the system into a completely unusable state.

Which is a shame, because I really wanted to like Zentyal. It is based on a newer and arguably better Linux distribution than ClearOS, and it has some really nice features. But I just can't deal with software that crashes when we're talking about a mission-critical server. It just isn't going to work. There's some places elsewhere in my infrastructure that Zentyal can live, but the border router? Nope. Not happening. So it goes.

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