Possible alternative: Raspberry Pi + Modem [LWN.net]

Possible alternative: Raspberry Pi + Modem

Posted Jul 29, 2014 21:25 UTC (Tue) by debacle (subscriber, #7114)
Parent article: The EFF launches a router project

I thought about replacing my proprietary home DSL modem/Wifi router combo with a free software, but I really don't want to use any specialised distribution, such as OpenWRT or the new EFF project (which I welcome).

Now I bought a Raspberry Pi B+ and a separated DSL modem and hope to make it run as a replacement for my proprietary stuff just by installing Debian with PPPoE and HostAP. Let's see when I find a free weekend for this...

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Possible alternative: Raspberry Pi + Modem

Posted Jul 29, 2014 21:42 UTC (Tue) by dlang (guest, #313) [Link] (10 responses)

> I really don't want to use any specialised distribution, such as OpenWRT

OpenWRT isn't much more specialized than Debian is

It's designed to work on much smaller, less powerful devices than Debian is, but the router hardware is smaller and less powerful only in specific ways.

a 3800 router is going to outperform a RaspberryPi at network related tasks due to the fact that the Pi has to put all it's networking through it's USB interface (which has significant bufferbloat issues remaining by the way)

I would suggest that you go look through the list of packages available for OpenWRT and then see what you need that's missing.

Possible alternative: Raspberry Pi + Modem

Posted Jul 29, 2014 22:23 UTC (Tue) by debacle (subscriber, #7114) [Link] (9 responses)

Of course, Raspberry Pi is not the perfect HW for this, and Debian does even support hardware floating point on it (Raspbian does, however). With OpenWRT I'ld probably miss dpkg and apt, AFAIK. Nothing wrong with OpenWRT, but I like to stay with my universal OS :~)

Possible alternative: Raspberry Pi + Modem

Posted Jul 29, 2014 22:47 UTC (Tue) by dlang (guest, #313) [Link] (2 responses)

Openwrt has opkg, but if you are deciding based on the package manager, go for it.

I'd love for someone to take the time to make a installation profile that could be squeezed down to a router.

I was just taking issue with the description of OpenWRT as being a specialized distro.

you can define terms so that anything other than Debian is specialized, but if you go a bit broader (to include things like Fedora, Suse, RHEL), then OpenWRT should qualify as well.

Possible alternative: Raspberry Pi + Modem

Posted Jul 30, 2014 21:26 UTC (Wed) by debacle (subscriber, #7114) [Link] (1 responses)

I just distinguished between a specialised OS such as OpenWRT, which runs only on routers, and an universal OS, which runs - more or less identical - on a server, a desktop, or an embedded device. The latter could be Debian (my choice) or Fedora, Mint, Redhat, S.u.S.E., Ubuntu etc., of course. To me it is an advantage to use the same OS for different purposes, but this depends very much on individual needs/choices.

Possible alternative: Raspberry Pi + Modem

Posted Jul 30, 2014 21:32 UTC (Wed) by dlang (guest, #313) [Link]

Openwrt runs on x86 systems as well, again it's not as limited as you think.

It runs on more types of devices that Fedora does.

Remember, it's still using the Linux kernel, and the userspace is still *nix. So it's not nearly as limited as you are thinking.

Possible alternative: Raspberry Pi + Modem

Posted Jul 30, 2014 5:13 UTC (Wed) by drag (guest, #31333) [Link] (5 responses)

Home routers are not really 'universal' devices. I normally see the proliferation of different Linux distros as largely a waste of time (beyond somebody who likes it as a hobby), but this is one of those cases were a custom Linux OS and unique package manager is entirely justified.

These type of devices feature specialized hardware like a programmable switch that will be very poorly handled by typical Linux distributions.

Openwrt is a fine Linux operating system and is worth learning how to operate.

The patches/improvements coming back in from Cerowrt has made the latency and performance of my home network's connection to the internet increased significantly. This has brought tremendous benefits when it comes to things like bittorrent traffic and VoIP and has laid waste to the vague suspicions of the ISP being dickheads... In the vast majority of cases it's people's home routers that suck, not the ISPs.

I really doubt that throwing Debian into the mix would yeild a superior router.

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Now if you really want to use Debian for this sort of thing keep in mind that the future for 'Enteprise' networks is 'Software Defined Networking'.

That is instead of screwing around with crap like 'Vlans' and struggling with managing QoS using expensive Cisco gear... you just make a 10GbE/40GbE network that is simple as can be (while maximizing 'east-west bandwidth rather then north-south in traditional network models) and then run a entirely software defined network stack on top of that. This is very effective, very cheap, and works very well. Network folks tend to be sticks-in-the-mud and love their vendors, but eventually it's going to start having a big impact outside of the large OpenStack cloud providers.

This way when you do your 'cloud' people can define the network by how they want the network to be, on the fly, via web interfaces or whatever. Just let the consumer in your business decide what sort of network they like to see and then build it for them without having to configure a single firmware or wire up a single port.

To enable this sort of stuff one of the pioneers is 'Culumus Networks' and they have developed a commercial Debian-based Linux distribution to install on various 'white box switches'. So instead of using big proprietary gear from companies like Cisco you buy generic switches from ODMs from Korea (or whatever) and install Debian on it to control the hardware backplane.

Another approach is to take a cheap 'desktop' Linux system and stuff it full of dual port NIC cards and install Debian on it. You can use OpenVswitch to manage the bridge ports, which is massively more capable then the traditional 'Linux brctl-based switch' that is very common.

From there you can take a look at things like Openflow and OVSDB to peer into the future of network management.

This sort of stuff is going to be a big deal in a couple years so while it's a lot more expensive then a openwrt-based home router it will allow you to keep using Debian and potentially get marketable skills and contribute back to Debian making it 'more universal'.

Possible alternative: Raspberry Pi + Modem

Posted Aug 1, 2014 14:54 UTC (Fri) by kjp (guest, #39639) [Link] (4 responses)

Fascinating post. It seems like you're virtualizing the network, just like everything else is being virtualized...

Possible alternative: Raspberry Pi + Modem

Posted Aug 1, 2014 18:45 UTC (Fri) by dlang (guest, #313) [Link] (3 responses)

yep, all your security boils down to control over the management server, if you get hold of that you can configure anything to talk to anything else.

convenient if you have a network that changes a lot (like a lab), for a production network I'm not so sure.

Possible alternative: Raspberry Pi + Modem

Posted Aug 1, 2014 20:47 UTC (Fri) by raven667 (subscriber, #5198) [Link] (2 responses)

That's in some way the same security problem of any network management plane, there is less fundamental difference between a JunOS or IOS supervisor and a PC running Linux than one might think, in fact most of the modern network gear runs on Linux or FreeBSD, sometimes on re-badged commodity servers, with just an old-timey CLI put on top. Whether you have an SDN controller or management server talking over a network devices or you have a chassis connected to a FEX it is surprisingly similar when you get down to the details. So protecting your management plane, which has traditionally been done with local packet filters/ACLs on the device could be extended into the new designs.

Possible alternative: Raspberry Pi + Modem

Posted Aug 1, 2014 22:10 UTC (Fri) by dlang (guest, #313) [Link] (1 responses)

That is true, but the more you centralize, the more dangerous that control system becomes. With the virtual datacenter you have the same system configuring the switches as is configuring the servers.

As I say, it's nice for highly dynamic environments, but I question the value of it for production networks.

There's also the question of if the dynamically configured switches are going to create unexpected bottlenecks. not a problem on a small network, but a serious concern on a large one.

Possible alternative: Raspberry Pi + Modem

Posted Aug 2, 2014 23:55 UTC (Sat) by bronson (subscriber, #4806) [Link]

Production environments tend to be highly dynamic these days.