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Trouble Ahead for Internet Routing Tables?
joabj writes: "This article in Light Reading, a fiber optics news page, claims that the Internet's routing tables are ballooning in size and within a couple of years "equipment won't have enough processor power and memory to handle them." The article draws its conclusions from the dramatic increase in the number of BGP routing tables over the last six years and the predicted need for more IP addresses for all those pervasive computing goodies we've been promised."
I don't see how this is different from IP-IP encapsulation.
As for addressing the cost of renumbering, we should recognize that IP addresses have become a scarce (in the economic sense of the word) resource, and should be now priced. Given a cost for holding onto an IP address, people will figure out how to relinquish the ones they're not using.
-russ
Don't piss off The Angry Economist
Can someone translate this posting into English for me?
-russ
Don't piss off The Angry Economist
I think the answer is that, as IP connectivity from the outside world becomes mission-critical for business applications, businesses often want to deal with more than one ISP, or at least more than one technology (e.g. cable modem plus DSL) so that their customers can reach them even if their primary ISP is down, and to improve performance. To some extent, you fix this by using reliable ISPs and hosting services, or by using fancy DNS tricks to make it easy to find the connections that aren't down or that will give the fastest connections. But ultimately, you get yourself a BGP number and advertise your routes diversely so you can get diversity.
How do we find alternatives to this? Either ISPs need to come up with ways to handle it for their customers, or routers need to get bigger and faster, or we need alternative protocols that make it easier to avoid BGP. A good local ISP can provide this - buying service from a couple of big carriers, and providing enough transparency and responsiveness that customers trust them, and enough customers that their one BGP number supports multiple customers. Hosting centers also do the same thing, and let their customers avoid access circuits as well. But it's tougher to make it work for customers who have offices in multiple locations.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
First of all, I've set up Potsdam State so all their client IP addresses come out of a bootp/dhcp server using static assignment. So their cost to switch to a completely different network is trivial. Change a few servers, edit /etc/bootptab, done. If your site doesn't do this, then it's poorly managed.
I can't say how many addresses your site needs. All I can say, as an economist, is that an IP address should have a price. If the price is worth paying, you'll pay it, and you'll have the addresses you need. Or if you have too many addresses, it makes sense to sell some of them. And if the price of an IPv4 address becomes high enough, it will justify a switch to IPv6.
It's it amazing how well a free market works? Instead of having to have endless discussions, and wailing and gnashing of teeth about routing tables and switching to IPv6, you just turn IP addresses into private property and let the market work it all out.
-russ
Don't piss off The Angry Economist
That's an interesting point about a direct routing table. In a couple of years, putting a 64-bit processor into your router with 48 bits of physical address space might be entirely possible. More than enough space to keep a route for every single address. Your route-lookup time should be O(1), right? If you actually had a network route, you could just store it as a bunch of individual host routes. Cool.
/32 network. Maybe I'll multi-home my DSL connection. Yeehaw! :-0> What a great idea! I'm off to the patent office...
Sure, BGP would probably freak out, and it might not be a good idea to update the core routing table every time some laptop reboots. The table would never converge, but what the hell? Why not? In a few years, the necessary memory won't be worth squat. Embedded processors will be running at 1GHz. BGP would probably need some updates to keep route flapping down. It sounds scary, but in a few years this will be totally doable.
It gives quite a few advantages, also. 100% of address are portable. Addresses can be handed out without any concern for the effect on the routing table, making for very efficient distribution of IPv4 address. IP mobility becomes a non-existent problem. Most importantly, I can finally have my own personal, portable, routable
This seems to be more of a scare article than anything else. This is primarily a problem of memory. Given the rapid advances in the RAM industry, I would be suprised if the global routing table could grow too fast. Even the article itself says that within a couple of years, routers might need gigabits of memory. So what. Is spec'ing out a whole GB of RAM on a > $100K router really going to be a big deal in two years? Hell, if you bought 1GB of RAM for Cisco's top of the line router (12000 series GSR), you would spend ~$30K today. Moore's Law says that cost will drop to less than $10K within a couple of years. That's chump change on a serious router. Cisco charges that much for the power supplies alone.
;-)>
Let's face it. The global routing table is never going to stop growing. It's certainly never going to get any smaller. Every year the core routers will need more memory than the year before. Is this a bad thing? That the Internet is growing? I don't think so. Personally I think everybody who wants it should be able to get portable address space. But, that probably would melt down the routers. Not to mention exhausing the IPv4 address space
(* Babelfish Mode On *)
Fweep hanburger splodge router the aggregate, nerd meep fubar rezrov gaspar.
Alternatively, it might translate to:
I hate renumbering. Everyone I know hates renumbering. We can afford to buy more routers, and have them load-balanced. Exponential growth isn't a problem, provided it includes your bank balance as well as your throughput.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
(That's why it's amazed me that the IPv6 developers chose NOT to focus on IPv4-in-IPv6, but rather on IPv6-in-IPv4, which is relatively useless, once you pass the half-way mark.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Fasinating... I used to work for a company that was with the worst offender (BCnet - that's the BC Government's networks).
Doesn't surprise me at all that they could be doing things MUCH more efficiently. There's so many groups politicking there, it's terrifying.
You'll just see more route aggregation. Why is this particularly a problem? Renumbering isn't that hard.
-russ
Don't piss off The Angry Economist
... Film at 11.
(Sorry, I had to do it)
Wah!
Why do devices that only really need temporary internet access get permanent IP's? If we didn't have all of these extra devices crowding available IP numbers, perhaps there would be no need to develop a more complex numbering system.
- I don't care if they globalize against free speech. All my best free thoughts are done in my head.
I'm exactly thinking tier 1 NSPs will role out a different protocol. It could very much happen VERY quickly if for some reason BGP was imposing a significant cost/performance overhead as opposed to an alternative solution. The main reason why changing from BGP is crazy right now is that BGP meets their needs and it's in place. Once that's no longer true change will take place quite rapidly.
sigs are a waste of space
No, we don't need IPv6. That's why it hasn't been implemented yet. We can get along with IPv4 just fine by aggregating routes. But before we can do that, we need to scavenge IP addresses.
Yes, the decision to allocate all those class B's was reasonable at the time. It's not reasonable now, and those IP addresses are needed.
-russ
Don't piss off The Angry Economist
A few folks have talked about how we're running out of IPv4 addresses and need IPv6 yesterday. Others are saying "CIDR fixes this, or at least mitigates it."
All I have to offer is data. CAIDA has a chart of the IPv4 address space. Look at all of that wasted space.
IF we could CIDR-ize and allocate IPv4 more efficiently, the problem will go away.
Will we ever go to IPv6? If there's a compelling reason to (and not just "it's better" or "it's more technically correct"), then we will. Otherwise, we'll continue to hack on IPv4 for as long as it'll hold up.
Computers are useless. They can only give you answers. -- Pablo Picasso
claims that the Internet's routing tables are ballooning in size and within a couple of years "equipment won't have enough processor power and memory to handle them."
Am I the only one who thinks it foolish to try and predict the kind of processor power we will have in a couple years? A couple years ago, the routers available probably wouldn't have been up to par with the traffic the internet currently generates. I'm no expert though...
Own your own piece of slahdot.org!
So you're saying that because of mobile support, every packet has to get about 40 bytes larger, thereby raising traffic on the backbones, LANs and everybody else's networks? Hardly a good idea!
I do note that "Class A" address space 64-126 was never issued, so a LOT of CIDR blocks can be released there.
I thought this was fixed by CIDR and route aggregation. Plus, many of the backbones will not route to allocations smaller than X, where X may change if their routing tables get too big. This forces people with small allocations to move to a larger, aggregated allocation, or live with the fact that their IP address space is no longer routable.
Yeah, if every coffee maker in the world gets it's own IP address, is hosting a website about it's personal stats, and can be turned off and on via the web... We're kinda fucked. The big question being, who really wants this shit? A lot of stuff will be on tiny intranets, so I doubt that we really have much to worry about. I imagine that your coffee maker and fridge will post to a household webserver, that way you can get aggregate data which is much more managable, and also much more meaningful/useful anyways.
Now you will recieve spam for expensive coffee beans every time you make a few pots! Enjoy!
Eh...
Since I'm a Symbol employee, a quick clarification:
The Symbol SPT1700 Series either have a wireless Spectrum24 network card, or a Novatel Minstrel radio modem. The Spectrum24 card can either use a static IP address, or talk to a DHCP server. The radio modem has a static radio address, and an IP is given to the owner when s/he signs up for a wireless account with some provider.
The SPT1700 is just the base model with no wireless stuff. The SPT1740 has a Spectrum24 card. The SPT1743 has a 11 megabit wireless network card. The SPT1733 has the radio modem.
If you really want to know more about the above models, head over to epog.symbol.com and look them up. Username and Password are "guest"
Note that the SPT1700 line has a Type II PC Card slot, so all the above wireless stuff is just a PC Card added to the device at the factory.
"I may disagree with what you have to say, but I will defend to the death your right to say it"
"I disapprove of what you say, but I will defend to the death your right to say it."
- Evelyn Beatrice Hall
Alright.. so first off, this isn't news. Anyone following the NANOG list knows that the routing table is increasing exponentially with the rest of the internet. There isn't anything that can be done about that, realistically. The aggregation Nazis will scream day and night that they can fix the Internet if you would just let them aggregate things properly. Fine, but that would require a total renumbering of the internet, so it isn't at all possible with IPv4, unless everyone out there really feels like renumbering every machine on their network with a publicly addressable IP. Think about that for a minute. They'll scream that they can do it without renumbering, but they're wrong. The routing table is an intricate mesh of advertisements and if everything was aggregated, nothing would work right. BGP's first method of selection of routes is the longest match rule, whereby when you're choosing a route to pass traffic on, you choose the most specific advertisement, eg choose a class C rather than a class B advertisement. If everything was aggregated into /20 or larger blocks, there would be no practical way to load balance traffic in a multihomed environment (when you have transit through more than one ISP).
;)
And secondly, BGP isn't the cause for the routing table growing, it is the cure. There is no way we would still be using IPv4 without BGP. It saved the internet by introducing classless routing.
The answer to this is simple.. upgrade, upgrade, upgrade. There are routers out there that can handle far more than the internet has to throw at them right now.. it's just that Cisco doesn't make them. Juniper does.. check them out. They built a router off some sweet hardware and BSD. You can type 'start shell' in the router and drop to a BSD shell, and they have the route processor to chew through a routing table many times the size of our current table.
ISPs need to keep up with the growth and upgrade their routers, or they will have problems. Much of the instability of the 'net is due to that now, routers get overloaded and reboot and cause all kinds of churn in the network, which overloads other routers, which reload.. you can see the cascading effect. The ISP I work for had to upgrade all of our older routers to 128m of ram and newer route processors.. if all the ISPs did this, there would be no routing table problems. They just don't want to spend the millions they need to to upgrade their infrastructure, unless the users start screaming. So start screaming at your ISP! (unless it's mine.
//Phizzy
"Most European technology just isn't worth our stealing," -- Former CIA chief James Woolsey, referring to Echelon
An interesting point. The good news is that the growth curve for log(n) is much flatter than Moore's law's exponential curve. Indeed, if n is growing exponentially, that means you have a linear growth curve.
l
While memory speeds haven't been improving as per Moore's law, they have been improving. There's an interesting article on some of the techniques to help with the problem at:
http://www.acm.org/crossroads/xrds5-3/pmgap.htm
I think in the 6 years that these growth numbers are talking about we've gone from 33MHz 32-bit memory buses (yes, pentiums already had faster buses, but what I'm describing were pretty common) to the point where we now have 133MHz 128-bit (and in some cases even wider) double pump buses pushing data into increasingly faster and larger cache memory regions. Then you throw in ideas like compression and you can imagine that memory speed has been improving well enough to keep up with this growth.
sigs are a waste of space
Also see my MPLS node on everthing for a short and sweet overview.
-AP
If it's referenced on Slashdot, is it nodevertising?
The problem is not the number of IP addresses, static or otherwise, the problem is the number of routable networks, since that is what determines the size of the routing table in a backbone router.
Students are allowed to run servers from their dorm rooms (just not kiddie porn servers, hehe). 8K addresses would work just fine for them. That's 1/8th the numbers they currently have.
-russ
Don't piss off The Angry Economist
Ok, the internet is in trouble.
The internet is ALWAYS in trouble, it's the normal state for the monster. Well guess what? We'll fix it. We'll fix it again, and again, and again if we have, and we'll have to.
It grows, it writhes, it creaks and groans under the strain. It mutates and then mutates again. It's a digital age " The Blob."
But it feeds off the energy of its users and continues to grow. It shows every sign of continuing to do so.
Looking years down the road to see where such an amorphous beast might be headed serves some purpose I suppose, but life is what happens while you're making other plans, and I've found this creaky old gem more applicable to the internet than just about anything else.
Who the hell KNOWS where the whole thing will be and what it will look like in just a few years time.
Not I.
Links:
Cisco - IP+ATM Solutions
IETF MPLS Charters
-- Fnord.
giving each coke machine a phone number ..... and causing us all to change our area codes every so often ....
Sure the death of the internet is imminent - again!
Meanwhile, dumb devices (like the lightbulb on your porch????) don't need to be on the internet directly - and probably shouldn't be. You want the light to turn on when some newbie in Lower Slobbovia mis-types the URL for 'Naked Schmoos Live 2343988'? NAT on gateways can concentrate an awful lot of dumb (and not-so-dumb) devices into a single IP.
And a core router needs gigabytes of memory? So what? The cost of the memory is negligible compared to the cost of the core-capable routers. Besides - a direct (i.e. one entry per possible IPV4 address) routing table would only need 4G entries, and be faster than a heirarchichal lookup anyway. If you have less than 256 ports on the router, then thats under 5GB memory. And if you just route on the first 24 bits, it's only just over 16MB.
Ok, so that won't work with current routers - but they'll need to be upgraded or replaced for IPV6 anyway.
And if a router ends up handling dual duty IPV4/IPV6, then IPV6, with it's built in heirarchy of address bits and closer coupling between address bits and routing, is hopefully going to require fewer routing resources than IPV4. (Or an IPV6 network running on IPV4 tunnels could use the existing routers just to access the bandwidth).
Meanwhile, as more and more home users connect, we're going to see more ISPs putting them ALL on a single IP address (Can you say NAT, Mr Newbie?) for two reasons: 1), a firewall and web proxy at their gateway lets them use fewer IP addressses and bandwidth, and 2) the customers can't run "unauthorized servers".
Hmm. The entire @home network moved onto a single class C network address? Nahh.. But possible. (Even more possible in the future if they provide a tunnel to an IPV6 router?).
But 'The death of the Internet' again? Hardly. Saturation? Maybe. And I'll bet that until it DOES saturate, nobody's going to be offering IPV6 connections for quite a while.
Liquor
Liquor
Sanity is a highly overrated commodity.
- A.P.
--
* CmdrTaco is an idiot.
"Remember when the U.S. had a drug problem, and then we declared a War On Drugs, and now you can't buy drugs anymore?"
Redundant -- perhaps, though even that wouldn't really be fair as its post #18 and was probably up fairly soon after the article and started before the other posts of this type were finished/poste.d
This will not necessarily happen. It's quite possible that IPv6 traffic and IPv4 traffic will be split and passed off to different routers. This would provide incentive to use IPv6 as it would presumably be faster. Additionaly, even if Dual-IP-layer routing is necessary, one would hope that once IPv6 arrived, the IPv4 routing tables would stop growing so aggressively, as new IP's become IPv4 addresses. Should that prove to be the case, things will be easier.
;-)
P.S.: I presume you mean IPv4 rather than IPv5.
sigs are a waste of space
This is not a serious problem. What is a serious problem is all the sites that were allocated 2^16 (many colleges) or 2^24 (HP, Stanford, Interop, e.g.) addresses back when there seemed to be an infinite supply. For example, Potsdam State University has a class B. They only have 500 staff and 3000 students. What are they doing with 65,534 addresses??
-russ
Don't piss off The Angry Economist
Film? How quaint....
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
The problem is that the core routers are doing the wrong job.
/24. Now if that core router has 16 interfaces, you need 16 million nibbles of memory for its table. Thats 8Mb. You only get into trouble when you have several good routes for the same destination and then you need to do a level if indirection where you can look at that routers entry in the full routing tables. You build a seprate system to update those tables since they don't have to be real-time, they have several seconds after updates to get the swtich table updated.
Assume that all allocations are all
the article is saying that in a few YEARS we are going to need more memory and faster processors for our routers. the problem with this is where? I don't see any slowdown in the hardware advances we are making. /can find more efficient ways to do it, all the better. I am just saying that this might be a problem if we were running out of space tomorrow but in a few years I am confident the basic hardware will be much better than it is now.
if we want to
You're actually focusing on the wrong problem. Except if you focus on the right problem, it turns turns out to be even worse than you suggest.
It isn't simply a case of addresses for trivial devices versus "real" computers. A lot of computers -- real serious computers -- can get all the the access they need without using any address space at all. RFC 1597 sets asides IP numbers that cannot be used for "public" interaction. These addresses are valid only for intranet traffic.
The machine I'm using right now is a case in point. My employers do not want anybody not on our campus network accessing this computer. So I don't need an IP number that's valid in the Internet at large. Instead, I have a Class A address in Network 10. Addresses in 10.*.*.* can be reused endlessly, so long as they're not re-used on the same network.
I used to work for a major computing company that was extremely paranoid about off-campus access to their systems. But for some reason (probably institutional inertia) they assign IP numbers out of their permanent allocation. So that's thousands of IP numbers used unnecessarily. Plus they have a permanent shortage of IP numbers for internal use. Plus, every once in a while, a hacker finds his way through the firewall...
Perhaps I speak in ignorance, but it seems to me that nobody needs a public IP address, permanent or transient, unless they have a server or peer app. (Age of Empires anyone?) Thus 90% of all users -- especially the users of "real" computers -- are just wasting address space. And making themselves vulnerable to boot.
On the other hand, it makes perfect sense to assign an IP address to a gun. You never know who needs to kill who....
__________
Troll? Who moderated this post? Vint Cerf?
We said this same thing in 1995 when the two big routing points at the time, MAE East and West required routers greater than the Cisco 4000 series which did not have the memory to handle the routing tables.
We also thought by 1997 or 1998 we would be out of the original IP space.
Guess what? There are still tons of IP addresses left and more being recycled everyday. Internet access providers are merging and going bellyup everyday, returning IP space back to other backbone providers. Network security companies are moving public networks to private IP space to keep out scanners and sk's.
This kind of fearmongering has been going on for years and all it leads to is IP hoarding.
man every time someone thinks the computers of the world are going to melt in a year... two years...50 years... there's either a fix in half the time or when the time comes it's less of a disaster than they expected.
You don't understand. The reason that "there's a fix in half the time" is because someone writes an article or otherwise brings up the fact that there's a problem in the first place. It's the problem that no one finds or mentions that will kill you.
What we have here is validation that "many eyes make bugs shallow," but it still takes hands and minds to FIX those bugs.
Exactly how big is a routing table? I've never seen one, but given that they can fit inside a computer they must be pretty small. If they get bigger why can't we just keep them in that big empty hole they dug for the Supercollider in texas?
Let's go through a number of things that came up here:
sigs are a waste of space
Hell, if you bought 1GB of RAM for Cisco's top of the line router (12000 series GSR), you would spend ~$30K today.
Every time I read one of these articles, I'm initially thinking, "Wow, we can't keep up." And then I remember what Cicso passes off as big-bucks equipment is lame-ass compared to off-the-shelf desktop computer components. My biggest router is a 3640, used internally to route between various LAN segments, and its selling around $5k now, and I bought mine two years ago (along with RAM and ethernet cards). With a lame R4000 CPU and 96MB RAM, it's not a particularly impressive computer.
Given that SMP capable systems with 800Mhz CPUs (mobos, CPU, and maybe RAM) are running ~ $1000, why can't we "solve" the routing table crisis with some cheap, high-powered hardware? Moreover, why is Cisco stinging us along with overpriced, underpowered hardware platforms? Because they can?
I know that Cisco equipment is capable of doing some fancy switching between interfaces that generic PC hardware wouldn't do, but has anyone ever put 4 of those 4-port NICs into a fast SMP box and compared its ability to route relative to a high-end Cisco box? Omit from the comparison the encryption modules and some of the other goodies that you can do on a custom hardware platform but which isn't totally necessary for vanilla IP routing.
Under IPV5, they will run out of IPs before they run out of memory!
Someone you trust is one of us.
Given that the Internet has undergone a transformation as of late, what with all of the theft of IP and violent imagery it propagates, I am happy about its demise. This ranks right up there with the inevitable heat death of the universe in terms of things that I look forward to.
Possibly, when your Internet (the Vint Cerf crappy one) is finished, Microsoft will invent you a new one. You will all probably hate it of course because they certainly won't permit any misdeeds that you all seem so fond of. Just nice clean fun and information with a little dash of profit for all.
Run along now children, play on your Internet while you still can. When Daddy builds a new one your decaying 386 machines won't be compatible and you'll all have to revert back to your BBS days.
Cunning linguists
Immediate thought: routing table sizes won't increase in proportion to the IPv6 address size increase, because IPv6 aggregates most of those addresses into prefixes and it's only the prefix that needs a route. In fact, with the IPv6 capability to put more networks under a single provider's network number, it may even reduce the number of routes.
Tis called a joke. Still, people will replace old equipment. It happens, we upgrade. It's not going to be a ONE DAY THE EARTH CAME CRASHING DOWN change, people are going to upgrade their equipment to cope with just the bandwidth. These other problems will be thought of as secondary, but taken care of in the upgrade, so why worry?
Eh...
What I would like is a generic proxy capability in my home firewall/gateway that allows devices that require some form of outside access to register, and as part of that registration, include some proxy code to be executed by the server when someone outside wants to access the device. Lots of different security models needed -- selected addresses at the power company are allowed to contact the electric meter, any address is allowed to access the Tivo recorder if they possess the magic password, etc.
Obviously, the code passed to the proxy needs to be processor and OS independent. Java could probably do the job.
Hey! A generic proxy server, software, the whole concept fairly obvious -- I'll bet the USPTO would grant a patent on this!
There's a problem with route aggreggation, and while bigger providers are more responsible, its still an issue. But lets put gigabytes of memory in perspective, here: my biggest personal box is sporting 512M of ram. Is a few gigs of ram any sort of shock for routers that cost hundreds of thousands of dollars?
It also wouldn't surprise me to see more auto-aggregation being done with spare cpu cycles as the routes propagate, which would probably help.
/. is running out of space for troll comments. Since the number of /. trolls is growing exponetionally and the number of real /. users is only growing linearly /. will soon run out of comment space for trolls. Therefore I think all trolls should go over to cnn.com forums and troll there for a while untill Rob and the gang can fix this troubling problem. (moderate TROLL).
Not to mention that ipv6 will actually help quite a bit.
I have been told that ip6 addrs are sorted geographically. This way a router can calculate a simple geographic "net mask" or two for a given interface.
Anyone have some details on this?
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