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question regarding multi-homing
by Simon Chen 31 Dec '09

31 Dec '09

Hi all, Happy new year... I have a question regarding multi-homing, mostly from stub network's operational point of view. My big question is: what kind of failures do you usually see from your providers? Link down? Link up, but withdraw some routes? Link up, no route change, but blackholing partial or all traffic? Anything else? Let's say that I have two local routers (Ra and Rb) connecting to two providers, A and B. If router Ra sees provider A with problems of the first two cases (link down, link up but withdraw routes), the Rb can easily step up. My question is, if I am using provider A as the default, but provider A has the third problem (link up, no route change, but blackholing traffic), how can I detect it and switch provider automatically? To state this problem in detail: I use a static default route on Ra to forward traffic to provider A, or receive 0/0 from provider A via BGP. For some reason, provider A can no longer reach a /24. My network cannot be notified (unless, I receive a full internet routing table). In this case, all I know is that my traffic to /24 is blackholed through provider A. In this case, is there an automatic way for my stub network to switch over to provider B? Do I have to do the detection and switch over manually? I don't think VRRP can help here, right? Thanks. -Simon

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Out of the office
by Andrew.Claybaugh＠securian.com 31 Dec '09

31 Dec '09

I will be out of the office starting 12/30/2009 and will not return until 01/04/2010. If you need immediate assistance please call TechSupport at 651-665-5000.

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ip-precedence for management traffic
by Luca Tosolini 31 Dec '09

31 Dec '09

Experts, what is the general opinion of using ipp 7 'network control' for management traffic like: telnet ssh snmp ..... The idea is that ipp 0 1 2 3 4 5 are used for user traffic ipp = 6 is used by default by routing protocols like BGP, OSPF, LDP ... this leaves out only ipp 7 for management traffic, on the premise that routing and management should not share the same queue and resources..... Thanks, Luca.

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Consumer-grade dual-homed connectivity options?
by Paul Bennett 31 Dec '09

31 Dec '09

Not sure whether this is an appropriate place to post this, but I thought I'd give it a shot, since you're all knowledgeable folks with regard to networking things... At home, I currently run two DSL lines. Right now, we just have two separate LANs, one connected to each line, with my wife's devices attached to one, and my devices attached to the other. For a while now, I've been thinking about setting up a load-balancing routing solution to give both of us access to both lines. I have the opportunity to acquire a refurbed Cisco Catalyst 2960 at a ridiculously low price. I also have access to a (nominally) spare quad-core 64-bit PC with 8GB of RAM. I say "nominally" because I'm thinking about setting it up as a media center / gaming rig connected to the TV in the den. That's largely beside the point, but it bears pointing out that keeping the PC available for my other needs would be a good thing. So. Is it going to be a more-effective solution to drop a few bucks on the 2960 and go through the hassle of learning how to set it up (and then setting it up), or would I be better off putting a secured Linux distro (e.g. gentoo-hardened, or something) on the semi-spare PC and running the load-balancing via iproute2 and friends? Either way, I'm looking at a learning curve, and a good amount of time fannying around getting the damn thing working -- there's a good chance I'd spend almost as much cash on the PC-based solution getting good-quality network cards, and maybe fast HDD tech (though it seems like RAM and cores would be more important than disk IO). What are your opinions? -- Paul

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just...wow.
by Jerry Pasker 31 Dec '09

31 Dec '09

I got this email inquiring about data center space, from the most honest scumbag, *EVER* today. Operational relevance? Well, if everyone would turn these people down, we'd have a lot less problems to deal with. Sadly, requests like these happen far too often, but never have I had someone come right out and explain what they were doing up front like this without having to dig in to it. Scumbag email: ------------ Hello, I need servers to host botnet controller. Botnet controller is software that sends tasks to bots. Bots are hosts which send spam emails to millions of addresses. It's not direct spam but abuses on botnet contoller are received from time to time. What is your policy in case of receiving abuses and what is your policy in case of receiving a lot of abuses? What is policy about spam (not direct from your ips as I mentioned above)? Is it possible to host botnet controller in your datacenter during long-term time? Thank you. -------------- The part that leaves me feeling good is that they do get abuse complaints from time to time. There's hope.

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Re: ip-precedence for management traffic
by David Hiers 30 Dec '09

30 Dec '09

> Totally out of the box, but here goes: why don't we run the entire > Internet management plane "out of band" This has been one of my favorite conversation-stoppers for years. The PSTN fought tooth and nail against the need for OOB control, but 2600hz was a problem that they could not solve, so they bucked up and paid for a control plane. Where do you think we'd be now if Phreakers, Inc. still had access to a PSTN with an audio frequency, inband control plane? Don't we insist on, and brag over, data/control seperation within our devices? Isn't it groovy when a frame is never seen by the switch's CPU/SUP? Sure, I'm streching the analogy a bit here to make a point: many of our problems arise from giving bearer traffic access to the control plane. If the world wants an internet that is as predictable and reliable as the PSTN, it'll bear the cost of protecting the control plane. A fundamental choice in the protection scheme is physical architecture. IB or OOB, it's always a good thing to be explicit in design decisions, and not adopt legacy/heritage decisions without consideration. David PS: If you want OOB access to your gear when your core switches freak out, don't let those switches touch any frame between your WAN link and console ports.

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Out of the office
by Andrew.Claybaugh＠securian.com 30 Dec '09

30 Dec '09

I will be out of the office starting 12/30/2009 and will not return until 01/04/2010. If you need immediate assistance please call TechSupport at 651-665-5000.

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why it happens short packet. Which network device is problem?
by Deric Kwok 29 Dec '09

29 Dec '09

Hi all I got the following message. UDP: bad checksum. From 67.204.26.203:1054 to 66.49.0.97:55290 ulen 43 UDP: short packet: From 67.55.92.141:23801 30368/46 to 66.49.0.0:24617 What is this meaning? Which network device is problem? Why it happens in the network? Thank you

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Robert Carlson/The Siemon Company is out of the office.
by Robert_Carlson＠siemon.com 28 Dec '09

28 Dec '09

I will be out of the office starting 12/28/2009 and will not return until 01/04/2010. I will be traveling in Asia and will be checking my emails frequently, but please be aware of the time difference.

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Revisiting the Aviation Safety vs. Networking discussion
by Owen DeLong 28 Dec '09

28 Dec '09

Those that remember the discussion may find this article interesting: http://abcnews.go.com/Health/wireStory?id=9394406 Owen

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