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Google Network The Internet Technology

Why Google Went Offline Today 110

New submitter mc10 points out a post on the CloudFlare blog about the circumstances behind Google's services being inaccessible for a brief time earlier today. Quoting: "To understand what went wrong you need to understand a bit about how networking on the Internet works. The Internet is a collection of networks, known as "Autonomous Systems" (AS). Each network has a unique number to identify it known as AS number. CloudFlare's AS number is 13335, Google's is 15169. The networks are connected together by what is known as Border Gateway Protocol (BGP). BGP is the glue of the Internet — announcing what IP addresses belong to each network and establishing the routes from one AS to another. An Internet "route" is exactly what it sounds like: a path from the IP address on one AS to an IP address on another AS. ... Unfortunately, if a network starts to send out an announcement of a particular IP address or network behind it, when in fact it is not, if that network is trusted by its upstreams and peers then packets can end up misrouted. That is what was happening here. I looked at the BGP Routes for a Google IP Address. The route traversed Moratel (23947), an Indonesian ISP. Given that I'm looking at the routing from California and Google is operating Data Centre's not far from our office, packets should never be routed via Indonesia."
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Why Google Went Offline Today

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  • by Anonymous Coward

    And I thought the internet was a series of tubes...

  • by Adeptus_Luminati ( 634274 ) on Tuesday November 06, 2012 @03:56PM (#41899085)

    ... Network Admins who have no clue. Like when just 4 years ago, Pakistan took down Youtube...
    http://securitywatch.pcmag.com/dns/285152-pakistan-takes-youtube-down [pcmag.com]

    Clearly this should be on the agenda for the new "Cyber Reserves" of the department of Homeland Security. If Google can be taken down by accident in parts of the world, then it certainly can be taken down on purpose. Route filters are your friends!

    CYBER RESERVES: http://www.techradar.com/news/internet/department-of-homeland-security-recruiting-for-cyber-reserve-1109906 [techradar.com]

    • Clearly this should be on the agenda for the new "Cyber Reserves" of the department of Homeland Security.

      Good god do I hope you're joking. The last thing we need is the US government involved, especially som quasi-military organization of retired people and contractors that get "activated" in an emergency, all run by the freaking Gestapo.

      I'm not even a anti-goverment person who thinks they can't get anything right... but I sure as hell realize that this is an international problem that has to be solved

    • by aaaaaaargh! ( 1150173 ) on Tuesday November 06, 2012 @04:29PM (#41899561)

      If Google can be taken down by accident in parts of the world, then it certainly can be taken down on purpose.

      Oh my god, that would be the end of the world as we know it... I'd have to use Bing for a few minutes!

      You're right, we need to get the cyber-army ready!

    • Ugh, don't remind us, or we will try it again in an act of holy desperation that even Saudi doesn't apply.

      In other news, youtube is still blocked for us.

    • Route filters are your friends!

      Sure a provider can and should filter routes from small customers and small peers.

      But a providers can't really filter routes from their upstreams (since the whole point of them is to provide you with routes to the whole internet) and it's difficult for them to filter routes from other large networks (since they have so many direct and indirect customers). So it just takes one large provider to be either sloppy (not filtering routes from their small customers) or malicious (introducing bogus routes themselve

    • Almost all BGP capable equipment at most exchanges is now able to filter the amount of address blocks each ISP can announce. Once someone starts announcing a whole lot more than the filter is set for, the announcements are ignored and alerts are triggered.

      While that mitigates problems, the actual solution is already being put in place. IP address blocks are being assigned to parties and those parties can sign routing announcements for those IP blocks using a PKI system. By having the BGP equipment check eac

      • by Bengie ( 1121981 )
        I don't directly work with routers, but how might a signed block help? Each network is different and has different routes, unless the owner of an IP block is willing to work with every network operator in the world, there is no way for them to sign a block to state said route is correct.
  • Another networking issue that is probably never going to go away, I'm just surprised it isn't used more maliciously than it is. - HEX
    • by Adeptus_Luminati ( 634274 ) on Tuesday November 06, 2012 @04:00PM (#41899173)

      Seriously, a porn link in your sig?

      Anyway... clearly Anonymous hasn't learned how to delete BGP filters and inject fake routes yet.

      • by Anonymous Coward on Tuesday November 06, 2012 @04:06PM (#41899285)
        Errr, yeah, what about that porn link? That's really... that's awful. I can't believe that they would have that there. Man, porn. Anyway, I've just got to go and do... a thing. Nothing interesting, don't you worry about it, just... Go about your business.
      • by Anonymous Coward
        Since when does erotic nudes immediately equal "porn", and clearly you haven't visited the site.
      • by Beardo the Bearded ( 321478 ) on Tuesday November 06, 2012 @04:44PM (#41899807)

        Seriously, a porn link in your sig?

        Anyway... clearly Anonymous hasn't learned how to delete BGP filters and inject fake routes yet.

        The only reason you replied was to bookmark!

      • We don't do Porn, we try to keep on the erotic art side of things, and thanks for drawing attention to it lots of visitors from your mention! - HEX
        • by admdrew ( 782761 )
          ...to be fair, you *are* using a TLD explicitly intended for porn.
          • Strategic decision, while I do own the hex.ms domain I knew once .xxx came out it would be as recognized and memorable as the big three .com/.net/.org and just try getting a three char name on one of those. :P Also when we started we wanted the "freedom" to do "porn" if the story/script supported it, but the major issue is the credit card companies, we wouldn't be able to use Paypal, etc, so we dropped the idea. - HEX
        • It's just that the link is right above the "Reply to This [comment]" link. Easy to click by accident. Somebody slashdoting from work may get in trouble or worse. And as for some other comment in this thread, no obviously I haven't clicked on it... I'm at work. Wait let me fix that... I'm at "work". Ok.

          • No wonder no one replies to me, they are all distracted by my link and visit my site instead! A bittersweet win-win situation! As for visiting from work, no one sets their alert threshold that low for even adult material, sure you might get a blocked page but you won't get HR on your back for it. Of course my area and level of IT we're exempt from filtering usually, too many good resource sites get erroneously filtered. (and we implement the filters lol) - HEX
    • by kasperd ( 592156 )

      Another networking issue that is probably never going to go away

      Oh, really? I thought Route Origin Authorisations were designed to address exactly this issue?

      • I call in the networking team/group when it gets to this point, but I've seen it happen so often behind the scenes at Fortune 500's as well as publicly like this occurrence to have heard that it's "un-fixable by design" from those networking folks. Glad to see some progress is being made to really fix the issue. - HEX
  • Can this system of Network addresses and border gateways also be protected by DNSSEC? It seems like a pretty wide open way for mischief. It seems like it should all be part of BIND, but then I know just enough about IP routing to get m'self in trouble :-)

    • by X0563511 ( 793323 ) on Tuesday November 06, 2012 @03:58PM (#41899143) Homepage Journal

      Nope. DNS doesn't mean shit if the routers are sending your traffic to the wrong place. (DNS points to an IP, which is (supposed to) point to the target machine. If that last part isn't working, the first part won't work no matter what)

      • by Anonymous Coward

        And this is why encryption is your friend, because you can't be sure whose networks your packets are going to travel through...

        On each protocol, not just DNS lookups - eg HTTPS, SSH etc.

      • And an historical note to what X0563511 said: back in the day, one had go to a Scientologist-ridden place (SRI) to obtain the host address from the IP numbers --- these SRI clowns actually referred to themselves as "physicists" and "scientists" not whackjob scientologists with their weird-assed orgone boxes, or whatever they called those string and tube crap.
    • by skids ( 119237 )

      Well, I'm sure a scheme could be devised, assuming one could reliably trust that they can get to an authoritative source.

      The question is really how far into the core can we move such security measures before it implodes. Core routers have to carry the entire routing table for every subnetwork advertised with external BGP in the entire world, and then worry about doing the same for IPv6 as it slowly kicks into gear. They are always in need of an upgrade, even right after an upgrade and sometimes even befor

    • by kasperd ( 592156 )

      Can this system of Network addresses and border gateways also be protected by DNSSEC?

      No, but I think Route Origin Authorisations can help.

  • by Aqualung812 ( 959532 ) on Tuesday November 06, 2012 @03:59PM (#41899149)

    From TFA:

    Someone at Moratel likely "fat fingered" an Internet route. PCCW, who was Moratel's upstream provider, trusted the routes Moratel was sending to them. And, quickly, the bad routes spread.

    Yes, someone at Moratel screwed up, but this is exactly why upstream ISPs should never allow advertisements from their customers for networks that their customer does not control.

    PCCW is to blame for allowing this to happen. Never trust customers with things that don't belong to them.

    • by Anonymous Coward on Tuesday November 06, 2012 @04:07PM (#41899295)

      PCCW is to blame for allowing this to happen.

      Again. They were also the upstream for the Pakistan-takes-down-YouTube fiasco.

    • by vlm ( 69642 ) on Tuesday November 06, 2012 @04:35PM (#41899647)

      Yes, someone at Moratel screwed up, but this is exactly why upstream ISPs should never allow advertisements from their customers for networks that their customer does not control.

      Another important point is its twenty freaking twelve and at a "respectable" ISP this was part of my job a decade ago. Too many customers try advertising too much stupid space. Rule number one for a BGP operator... never trust whats incoming from nobody. Rule number two is when you call in for support and 1st level call center tells you to reboot everything, tell them to F off and transfer directly to my desk unless you want to learn the joys of route flap dampening. Rule 2 is hilarious when there's a genuine catastrophic failure and like 30 customers all want to talk to me personally because all their sessions dropped when the Juniper caught fire or whatever it was... so beware.

      There are only three things funnier than a fat finger BGP route advertisement:
      1) Why can't I advertise my old /28 from AT&T on your network? Well dumbass thats their space not "your" /28, and secondly on the civilized internet everyone filters at /24 or bigger to keep out the riff raff so even if I was dumb enough to advertise a subnet of another ISPs space, no one gonna see it past our borders.
      2) Multihomed people who basically accidentally try to turn themselves into a transit network. Oh, you connect to L3? How nice. You don't really want to advertise that the whole freaking internet can route thru you to reach it, do you?
      3) Advertising space in BGP, maybe redistributing a static or null route, doesn't mean you can actually route it on your internal network. OK I see your measly little /20 and now that you let me know to update our filters, we can all see it via us on any looking glass in the world. Yes I'm quite sure it doesn't work and no its not BGPs fault, go fix your internal routing protocol and filters and GTF off my phone so I can go back to sleep. No for the 20th time its not a BGP problem just look at the looking glass I'm not filtering you anymore.

      The primary problem is BGP is a social layer 8 protocol for how network managers... manage. You don't learn that shit in a weekend training class where they teach you the exact syntax of "show ip bgp neighbor" or by memorizing AS path regex syntax or whatever. At least up till I got out of the business half a decade ago, no one was teaching anything like "this is how to use BGP while not making an ass outta yourself" class. No book either. I think "Internet Routing Architectures" and maybe the name Halabi sticks in my mind as a good theoretical book as I recall, but no one had a practical "real" hands on class or book. I suppose I shouldda done something about that but its been a long time now. Then again I've probably forgotten more about BGP that most one week CCNP bootcampers will ever know, so maybe its not too late anyway. Another "in my infinite spare time" project.

      Sorry if I've offended any /.er I've actually talked to on the job who Fed up, nothing personal... But since I carefully identified noone by name, at least no one knows you Fed up. If today I failed to offend anyone who Fed up while I was doing front line BGP support then I'll try harder next time. BGP is kind of the network engineering version of giving little kids boxes of matches. Its surprising more networks don't burn down, but boxes of matches are so blasted useful if you actually know how to use them safely so its not like we'll ever get rid of it.

    • by steelfood ( 895457 ) on Tuesday November 06, 2012 @05:34PM (#41900591)

      In the age of information, there is one thing people continue to forget: information relies on trust. And like sociology tells us, trust as a commodity is only easy to trade on a small scale. Trust is very hard to acquire in large populations.

      There are two fundamental flaws with the internet. The first is that it was originally designed and built on a small scale. Trust was not an issue. This is apparent everywhere, at every layer. Every piece of information received is inherently considered true. Validation is limited only to determining the accuracy of the reproduction.

      When trust became a problem, people attempted to address this issue via a glorified whitelist. Certificates were meant to address both concerns of the accuracy of the information, and the validity of the origin. Trust in the contents of the whitelist was implicit. It worked on small scales, but on large scales, it fails.

      The whitelist was used because of the second fundamental problem: statelessness. Trust relies on the continual accuracy throughout many interactions. It cannot be calculated or created out of materials, but is acquired over time. The more times the information is accurate from a particular source, the greater the trust in the information. Time requires state. It requires having both a before, and an after.

      The stateless nature of the internet makes it impossible to be fully trusted. Even if the internet had state, it is difficult to enough to devise an algorithm that will accurately calculate the trustworthiness of a piece of information. Trust is a judgment call. It is a product of emotion, not of logic. Without state, it is an impossibility.

    • by jon3k ( 691256 )
      And how exactly do you know which portable AS that a particular peer should be allowed to announce? If I have a customer come online tomorrow and they want to announce their own portable AS, what happens when I try to announce it upstream, and then the next AS peering relationship? Do I have to call you and have you update a prefix list, and everyone down the line? You're only thinking in terms of a stub AS not a transit AS (which is where the problem starts to really appear).

      See if you trust A and A
  • by DamonHD ( 794830 ) <d@hd.org> on Tuesday November 06, 2012 @04:00PM (#41899171) Homepage

    This sort of 'feature' did allow me once to escape from a misbehaving ISP holding me hostage and preventing me getting my mail to, for example, change my DNS glue records many many years ago. A helpful friendly new ISP managed to reroute traffic to me via them with a "bogus" routing announcement long enough for me to fix those records and then escape the old ISP when the new records propagated.

    Rgds

    Damon

  • Hardware failure? Sure, Indonesia hasn't attempted to censor the internet so far.

  • by hydrofix ( 1253498 ) on Tuesday November 06, 2012 @04:03PM (#41899229)
    China Telecom also hijacked web traffic to US government websites [cnet.com] in April 2010 for 17 minutes. At least that incident seems to have been a purposeful disruptions to capture sensitive data and/or try out a novel cyberwarfare tactic.
    • by jon3k ( 691256 )
      They're probably STILL going through that stuff. Crazy. I wonder how much traffic they dumped into pcap files before the route announcement got fixed.
  • Do the editors even read the submissions?

  • by Todd Knarr ( 15451 ) on Tuesday November 06, 2012 @04:35PM (#41899645) Homepage

    I get the feeling that upstreams should start to not completely trust BGP announcements from peers. I know in my firewalls the configuration knows which networks ought to appear where, and the rules are set to block traffic when that network shouldn't be able to appear on that interface. Perhaps it's time to look into having an administrative communication of which ASes each peer ought to be handling, and having the BGP system at the upstream filter out or ignore announcements for ASes that that peer isn't supposed to be handling. The problem I see with that though is that it works well at the edges, but the closer to the core you get the larger the list of potentially valid ASes and I can see it getting unmanageable pretty quickly. But with the number of these incidents, I think we need to do something to change the assumption that you can unconditionally trust peers to only hand you valid routing data, because that assumption pretty clearly isn't true anymore.

    • Re:Filtering (Score:4, Interesting)

      by vlm ( 69642 ) on Tuesday November 06, 2012 @05:03PM (#41900121)

      I get the feeling that upstreams should start to not completely trust BGP announcements from peers.

      Start? This was BAU at respectable ISPs a decade ago. Guess what I was doing at that time, endless Fing around with filtering. Bureaucratic level varied a lot over time but when I left that part of the biz it was crystallizing around something like the 800 number letter of agency process, where you need a company officer to fax a signed sheet verifying thats really your space and yes we really do have permission to advertise it. At least at that time ARIN did not do dun and bradstreet numbers and there's no way to verify via whois and everyones merging, so we needed that signed letter to protect us legally just as much as the internet needed it so we could protect the internet from them. At least as I recall.

      Basically if you are "Ford dealer of chicago" I have no legal idea if you're allowed to advertise ARIN's ford.com space, but if we have a LOA then at least if it all hits the legal fan we have a signed letter from a corporate officer at the dealership to get us off the hook (at least partially) when the real ford goes after us, or at least we can tell the "real ford" who to add to the lawsuit. Many a time I had to call the ARIN registered owners to verify an apparently unrelated minion should be advertising some of their space. Sometimes yes, sometimes no. It was always an entertaining conversation. Except for when the ARIN contact info was invalid. Then the swearing began.

      Most of the time, obviously, its just a dude advertising additional space with identical ARIN contact info as the old space, so it doesn't come to this level of paperwork.

      I don't know if the situation has gotten better or worse since the mid 00s.

      but the closer to the core you get the larger the list of potentially valid ASes

      Ah but that's not where you need it. At least not for black hole events like this. If I'm properly filtering at the border, I don't need to filter in the middle, in fact it shouldn't ever be even theoretically necessary and its none of the cores business what business deal I've signed at the border anyway. Also god help us there were people trying to what amounts to dynamically load balance and disaster recovery using BGP, not necessarily a "stable" situation anyway. Route flap dampening is enough of a PITA.

      • If I'm properly filtering at the border, I don't need to filter in the middle

        You absolutely have to filter when crossing an international border. National security requires it. Maliciousness can be of a military nature, and you'd better be expecting it. The network admin on the other side may be coerced, an eager participant, or unaware. You ever can't trust what he does or what he says.

        • by vlm ( 69642 )

          LOL I'm talking about AS borders you're talking about map borders.

          • by r00t ( 33219 )

            OK, but AS borders don't exist in some theoretical world where everybody plays nice. They exist in our normal world.

            International borders aren't just map borders. They are legal jurisdiction borders. Unfortunately, a corporation or AS can span an international border. This means an insider threat. Portions of your corporation may be acting against each other, and you can't make them stop.

            Maybe it could be **you** being ordered by your government to do something sneaky. Perhaps you will even eagerly voluntee

      • If I'm properly filtering at the border, I don't need to filter in the middle, in fact it shouldn't ever be even theoretically necessary and its none of the cores business what business deal I've signed at the border anyway.

        That's the thing though: this problem happened in part because the networks that peer with PCCW trusted PCCW not to advertise any ASes that weren't supposed to be attached to their network. And you can't assume that these days.

  • I don't know what says more about the change in the average Slashdot reader--the fact that the summary for this story assumes that the reader doesn't know anything at all about BGP, or the fact that this is the first comment to bemoan that.

    • Re:Shift (Score:5, Funny)

      by 93 Escort Wagon ( 326346 ) on Tuesday November 06, 2012 @05:18PM (#41900355)

      It's okay, those of us who aren't network admins just need to type "Border Gateway Protocol" into Google and... oh crap!

    • by mk1004 ( 2488060 )

      I don't know what says more about the change in the average Slashdot reader--the fact that the summary for this story assumes that the reader doesn't know anything at all about BGP, or the fact that this is the first comment to bemoan that.

      Even if most /. readers are technically literate, not all technical disciplines require even the slightest knowledge of networking. So why wouldn't it be OK for the summary to assume the reader may not know anything about BGP. If this were an article about IC processing, I might make the same comment if the summary assumed that the reader didn't know anything about IC fabrication. But I wouldn't, because I know that you can't be knowledgeable in all fields.

    • Slashdot is targeted at the tech-oriented crowd. The set of all tech-oriented people is quite a bit larger than the set of network administrators. It's therefore a good idea to explain what BGP is so that the mathematicians, scientists, engineers, etc, can understand what the article is about. Even for many network administrators BGP will be a thing they learned about and then mostly forgot, since it's not used directly by smaller organizations, and larger organizations likely have some admins responsible o
  • by guttentag ( 313541 ) on Tuesday November 06, 2012 @05:15PM (#41900321) Journal
    The Google logo got caught [google.com] with its hand in the ballot box cookie jar! It's all over Google's front page!
  • Google keeps having error messages and random reloads on Gmail, Adsense, but not in Adwords at least. Their websites are dependent on JavaScript and the scripts can not cope with load errors, so they keep reloading the page until the servers are overloaded. I suspect that they are not aware of this too, becasue I have seen it last month already and they did nothing. I suspect that they run buggy code.
    • by SuperQ ( 431 ) *

      I suspect you don't know what the fuck you're talking about. Also, that has nothing to do with PCCW not filtering BGP announcements.

  • by jroysdon ( 201893 ) on Wednesday November 07, 2012 @01:51AM (#41904441)

    UCLA's Cyclops [ucla.edu] is a great tool to monitor your own IP space and make sure you know immediately when this sort of this occurs.

  • Why the hell not? I thought the reason for the internet was to provide a way for data packages to get to their destination without having to have a particular fixed route. Does it says somewhere in the internet standard that data packets *must* be delivered using the shortest route possible?

  • Here's a summary of the summary: someone broke the internet. That's right, "the internet is broken" actually applies here, lol.

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