Can You Purchase Switch Hardware Without an OS? 70
dhahn asks: "I have a project where I'm building a large Linux router (about 40 ports or so). At this point, my only hardware solution is to purchase a box with lots of PCI-ish slots and fill them multi-port ethernet cards. I've looked into currently available solutions and haven't found anything that gives me the control I want. Does anyone know of where I could purchase a 'naked switch?' I just want the switch hardware with enough guts to allow me to customize a Linux OS and load it up." If anyone else has been in this situation, what did you do?
VLAN (Score:5, Interesting)
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The real question is, what speaks against a Level 3 Switch from a reputable vendor?
Or if a L3 switch doesn't offer enough options, a rather expensive and huge real router?
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I might want to add that if he goes the multiport NIC route, he's going to need a minimum of Gigabit Ethernet, for the autocrossover functionality. Otherwise, he'll have to wire up special patch cable
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You're not even correct about the crossover. Automatic crossover is supported on all kinds of 100baseT gear, although it is not required as it is in the 1000baseT standard (because the Fast Ethernet standard predates the tech).
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That's your big dig on Cisco? An article from 2005?
Cisco's IOS is proprietary, and designed from the ground up for this type of task. If you're anti-Cisco for some reason, there are plenty of other vendors that make similar equipment. If the original poster's project is anything but an interesting experiment, it's worth using the right equipment.
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if you would like (Score:5, Funny)
PCI-ish? (Score:4, Funny)
Buy Used (Score:2)
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Zorch depends on your needs (Score:2, Insightful)
Now, throw half a dozen servers on there along with a few machines th
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Interestingly, from a pure processing angle, to process 9320675.55 PPS, the corresponding number of packets for 80gbps with 9k frames, a system will need 932 MIPS... well within the range of a low-end Athlon or Pentium III processor. To p
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To be honest, unless I had some incredibly weird requirement, or a strange fetish for building my own kit, I'd go look for a proper router solution. My experience of using a *nix box as a proper, layer-3 LAN router isn't that great. There's something to be said for the custom-desi
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bandwidth limitations, and large PCI backplanes (Score:5, Informative)
- PCI bus bandwidth is going to hurt you hard. 32-bit PCI @ 33Mhz = 127Mbyte/sec. 64-bit PCI-X @ 66Mhz = 508Mbyte/sec.
- 100Mbit ethernet = ~10Mbyte/sec (assume 10b8 encoding, easier numbers).
- 127Mbyte/sec / ~10Mbyte/sec = 12 100Mbit ports only.
If you aren't deterred by this:
1. Get a motherboard.
2. Get a decent PCI backplane. A quick Google search brings this company:
http://www.commell.com.tw/Product/Peripheral/Back
and they have a backplane with 17 PCI slots.
3. Buy 4-port PCI 100mbit network cards (http://www.americanpredator.com they don't list it on their site, but I'm certain they do custom quad port cards, or can point you to somebody that can, $500/card for industrial grade hardware).
4. 17*4 = 68x 100Mbit ethernet ports.
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A lot of "server" grade hardware supports multiple PCI busses to eliminate this problem.
Re:bandwidth limitations, and large PCI backplanes (Score:5, Informative)
From http://en.wikipedia.org/wiki/List_of_device_bandw
PCI 32-bit/33 MHz 1066.66 Mbit/s 133.33 MB/s
PCI Express (x1 link) 2500 Mbit/s 250 MB/s
PCI 64-bit/33 MHz 2133.33 Mbit/s 266.66 MB/s
PCI 32-bit/66 MHz 2133.33 Mbit/s 266.66 MB/s
PCI 64-bit/66 MHz 4266.66 Mbit/s 533.33 MB/s
PCI-X 133 8533.33 Mbit/s 1066.66 MB/s
PCI Express (x4 link) 10000 Mbit/s 1000 MB/s
PCI Express (x8 link) 20.00 Gbit/s 2 GB/s
PCI Express (x16 link) 40.0 Gbit/s 4 GB/s
The big routers and switches use PCI/PCI-X on their backplanes and when some of them started doing 10Gig ethernet ports the ran into the PCI-X bandwidth limit of abouth 8.5 Gbit. So do like Cisco & the others did and start using PCI-E. I saw another post here mentioning multiport gigabit ethernet cards for PCI-E slots made by Silicom: http://www.silicom-usa.com/ [silicom-usa.com]
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However to reach the OP's goal of 40 ports, he needs 7 x4 slots available using those 6-port cards. I'm not aware of any system that provides that many lanes in such a configuration (Not that you couldn't build one, there are definetly 32-lane and 48-lane chips out there). It might be possible to get a pair of x16 -> (4)x4 convertors in an external box (still in the engineering sample state, but define
OS-Less-Switch won't help (Score:5, Insightful)
Some of the switch ASICs I'm familiar with [medium range broadcom, vitesse] are in fact slower at sending a packet through the host control interface, than at simply switching it to a port on which a host cpu might be connected. [Reference designs from the above have the host CPU connected to the host interface, and control packets, ssh, telnet, http, depending on the design captured and sent through it]. In that case, you'd need your host CPU to be connected to one of the ports of the switch, and then of course your routing speed is limited to the maximum speed that can be sent through a single port.
One of the posters above me mentioned buying a managed switch and using VLAN's, thats what I woulda suggested had he not beat me to it.
Good Luck!
Mod up (Score:2)
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Right now it's just a dumb switch with a management port, but I'd like to play with VLANs and SNMP management, and perhaps more. So a few specific questions:
1 - I've done some reading, and it indicates that DHCP just doesn't play well with VLANs, and it causes extra CPU overhead. How bad is this, really? I use DHCP primarily to ease adminstration, so IPs are managed in my DHCP a
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I haven't experienced any oddities with DHCP and VLANs(both layer-2 & 3). Extra CPU overhead is just the broadcast traffic involved. The ease of adminstration vastly out-weighs any minor extra cpu load.
Get a Cisco (Score:2, Insightful)
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Seriously though- Cisco makes terrible switches. Oversubscribed ports, slow backplanes, etc. Add to this the fact that their TAC has gone to pot (ask just about anyone on NANOG) and they're not a sound choice right now.
-sirket
Is this even a good idea? (Score:5, Insightful)
Not to be a dick, but if the poster has to Ask Slashdot about this sort of configuration, he or she has no business messing with this and should leave the design and configuration to grown ups (unless it's a lab experiment or something).
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Not to be a dick, but if the poster has to Ask Slashdot about this sort of configuration, he or she has no business messing with this and should leave the design and configuration to grown ups (unless it's a lab experiment or something).
You're being a dick, but the truth can be dicky.
What are you looking for? (Score:5, Interesting)
You are asking for independent ports. If you need to route through each port seperately and not 'switch' data between ports but 'route' it among them then you need router hardware not switch.
See the thing with switches is that chips are available with 4 ports or 8 ports and it automatically switches data in ASIC between ports. Usually these chips cannot be interfaced to a microcontroller and almost never have PCI interfaces.
You do need individual ports, not a switched collection of ports. So you need something with 7 PCI ports (7x4=28). There are plenty of 4-port PCI cards out there, but there must be 8-port cards too. I have seen plenty of 6-port motherboards. You will have to use PCI extension devices to get to 7 or 8 ports unless you find those 4+ port ethernet cards. Do keep in mind you cannot switch between all ports at wire speed. You'll need faster busses and powerful processors. At this point you're looking at highly specialized hardware like cisco juniper etc.
It is inefficient to route between that many ports on a single CPU. Its better to cascade entire routers if your design allows it or add switches to routers with fewer ports. Unless you are a telco providing high speed connections to ISPs or a central location breaking the bandwidth for many branches, I dont see why anyone will need a router with 30 ports. In any application when you need more processing power, you'd divide the algorithm and use multiple CPUs or multiple computers. In this case you can almost definitely use cascaded routers if you need that many ports in the first place.
I have a Cisco 4700M router with 12 10-mbit ethernet ports. Never needed more than 3.
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This isn't really a do-it-yourself kind of project though, as yo
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more data needed (Score:2)
You specify that you are building a router then request a switch hardware. What level are you managing your network at? What kind of throughput are you trying to get (10/100, 100 full, gigabit?) Are you managing at the port level or at the IP level (switching vs routing)?
Elaborate and maybe then we can get you some answers
Re:Hmmm (Score:4, Interesting)
I can't speak for the original poster, but in our case we needed VLAN's to be unique per port. That is, VLAN 100 on port 1 should be switched to VLAN 105 on port 2, and VLAN 100 on port 2 should be switched to VLAN 200 on port 3 and 4, and so on. Trivially easy to do in Linux, not so with a 3750. You can do it with VLAN mapping, but you can also buy quite a server for the price of a 3750 and the Advanced IP Services image. Oh and the 3750 supports only 24 VRF-lites, whereas you can run quite a few more OpenVZ instances with routing on a Linux box.
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That is, VLAN 100 on port 1 should be switched to VLAN 105 on port 2
What does this mean? You want traffic switched between the two ports? What's connected on the other end, hosts? switches?
Like I said... I'm confused.
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I want traffic switched between VLAN 100 on port 1 and VLAN 105 on port 2.
What's connected on the other end, hosts? switches?
Switches, I presume, MPLS routers perhaps. They are at other service providers.
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ummm why? (Score:2)
Why in the world would you want a router + 48 port switch all in one? so when you take the router offline the whole network crashes?
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Not to be rude, but this is how it's done in the real world. The fact that a switch "routes" is merely part of its feature set. Routing is switching. It's just that canonically, it's typically associated with layer 3 switching. Some switches even switch above layer 3.
Also, these devices don't go down. It's not really acceptable. As such they are configured with multiple, redund
It doesn't exist (Score:2)
For our next deployment we will likely go with a 1U switch combined with a 1U HP server, and
VLANs work great for this. (Score:3, Insightful)
I've done this for cases where I needed a small machine to run with more ethernet ports than it's actually got. Works great.
Sean
Used cisco or foundry (Score:4, Interesting)
Used cisco 3500s or 2950s with 24 or 48 ports are on the market for a few hundred (dollars or euros) each. Foundry workgroup switches are less than 100 euros right now. Cisco 7200s are just PCs inside, but their PCI buses are a different layout to allow hot swapping. Cisco Pix 515s are just commodity 1U intel pc motherboards, cisco didn't even bother doing a redesign to remove the superfluous connectors.
If you have enough money for a PCI-ish box and many quad ethernet NICs, then you probably could afford a used Juniper M5. It already runs BSD, and pretty much looks like standard PC hardware inside. A used M5 without any interface cards should be had for less than a new PC, its the interface cards that will cost you dearly.
If you follow my advice, then with any luck you will document everything you did along the way, and release a linux distro for some otherwise proprietary hardware. I'd like to see a cisco 2950 turned into a linux box with all kinds of extra linuxey features. What I'd love to see is openBSD's pf on a switch, so I could set per port ACLs and bandwidth shaping.
the AC
Router Hardware != Switch Hardware & Suggestio (Score:5, Insightful)
Routers have to look at layer 3. Back when I was writing code for a major switch/router manufacturer, most switch chips didn't pass the (de-encapsulated) packet up to the main CPU (or back down). The chip only gave notification that a packet arrived (etc) in the form of an incremented register. This meant the chips were unsuitable for routing because the main CPU had no visibility into the packet whatsoever.
Either of these designs generally require a separate Ethernet NIC for the main CPU, as the switch ports are too busy with external connections. That NIC might be connected to the switch chip on the switch's main board, or it might appear externally as a "management interface port." You'll be programming this NIC, too-- but hopefully, just with ifconfig(1M)
Suggestion: Look for commercial switch chips that can pass the packet to and from the main CPU. Find a company which has a COTS switch with the combination of your favorite switch chip and a CPU that will run your Linux version (or uCLinux). Make sure the implementation hardware is wired properly to be able to get the packets to and from the main CPU-- your favorite chip might have a separate HW interface for communicating with the main CPU that could be unconnected in the implementation hardware. At this point, you essentially have the naked switch that can route. Learn how to boot Linux on the implementation hardware and build a flash filesystem that the switch's bootloader will read. Then start writing code to add the capability you require (to routed?).
Suggestion: Once it works, sell the thing. Or open the source up for others. You went through a lot of trouble to get that capability in the system, and it's got to be so cool because it isn't already in a commercial router. You might consider selling it on the open market yourself, or finding someone to sell it to. Or drop it on Sourceforge for others to upgrade.
Suggestion: Or, you can get your cool feature embodied as an RFC and get the main router vendors to build it in. Or contribute the code to routed(or whatever). You can probably skip the effort of building this one-off switch/router.
Try ImageStream (Score:3)
Reference kits (Score:2)
You could buy a reference platform kit from network ASIC manufacturers. I know of the Broadcom XGS ones (chips that do L3 routing, L2 switching and ACLs in hardware), as my day job is at a company that uses these to do switch/router application software [lvl7.com]. The software's proprietary, of course, but Linux does run on those boxes.
That's probably many kilobucks, though, and you'd face the task of dealing with the awfully complex chip to get it to do what you'd want.
Another option would be to buy/license LVL7
"Switch" (Score:3, Funny)
http://www.apple.com/getamac/ [apple.com]
linuxdevices (Score:2, Informative)
Do like every other switch vendor does (Score:2)
Yeah, unless you really have a need to - customizing hardware is expensive, difficult, and prone to failure. Usually when I see questions like this, I assume they are from someone that really doesn't understand a problem and has decided to go dow
9 ethernet ports on a Sun (Score:2)
http://lfnet.net/blog/?p=41 [lfnet.net]
Mod parent up (Score:1)
Dude, get an account... you've got nothing to lose, and it's free. Plus, if you read often and meta-moderate, you can get mod points and mod up those useful posts