February 2012 - NANOG - lists.nanog.org

[NANOG-announce] Tutorials starting today, some available via webcast!
by Dave Temkin 05 Feb '12

05 Feb '12

For the first time, NANOG will be webcasting (and archiving) some of our tutorials. Beginning at 2PM PT, you can see John Kristoff give an Introduction to Shell and Perl Scripting for Network Operators, with a break from 3:30-4 and then starting back at 4PM PT with Intermediate Perl Scripting for Network Operators. Both tutorials will be available later for review. You may see all streaming options at http://www.nanog.org/streaming.php -Dave Temkin For the NANOG Program Committee _______________________________________________ NANOG-announce mailing list NANOG-announce(a)nanog.org https://mailman.nanog.org/mailman/listinfo/nanog-announce

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bgp history lookup tool?
by Mike 04 Feb '12

04 Feb '12

Hi, I am trying to diagnose an event yesterday where our provider appears to have dropped our routes and we were inaccessible from outside our provider. I thought somewhere someone was keeping a searchable database of bgp announce/withdrawals and it would be useful to have a peek and see if any such event concerning our prefix/as was seen anywhere. Mike-

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Please help our simple bgp
by Ann Kwok 04 Feb '12

04 Feb '12

Hello Our router is running simple bgp. "one BGP router, two upstreams (each 100M from ISP A and ISP B) We are getting full feeds tables from them We discover the routes is going to ISP A only even the bandwidth 100M is full Can we set the weight to change to ISP B to use ISP B as preference routes? Can the following configuration work? What suggest to this weight no. too? neighbor 1.2.3.4 description ISP B neighbor 1.2.3.4 remote-as 111 neighbor 1.2.3.4 weight 2000 If this works, how is ISP B upstream connection is down? Can it still be failover to ISP A automatically? If it won't work, Do you have any suggestion? Thank you for your help

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Some Smokeping doubts
by Grupo IPv6 04 Feb '12

04 Feb '12

Hi all, I’m using Smokeping (http://oss.oetiker.ch/smokeping/) and I have some doubs that maybe you can answer: - Why Smokeping needs to be connected to internet even when I have only one Target to a host in my LAN ? - What is exactly the Standard deviation calculated at the bottom right of the graphs? Can it be interpreted as Jitter? Or is there another way to know the jitter? - Why sometimes when I add a new host, for the first minute I get a list of errors saying that the RDD file doesn’t exist? This happens commonly? Is there any way to solve this problem? Many thanks, Gabriel

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Question about prefix list
by Ann Kwok 04 Feb '12

04 Feb '12

Hi I read this prefix list. Can I know why there is "le 24" after network block in /22 and /21 Why don't have "le 24" after /24? I also saw another prefix list before. They use "le 32" instead of "le 24" What are their different? ip prefix-list prefix-filter-as100 seq 10 permit 202,168.136.0/22 le 24 ip prefix-list prefix-filter-as100 seq 20 permit 202,22.92.0/22 le 24 ip prefix-list prefix-filter-as100 seq 30 permit 202,21.148.0/22 le 24 ip prefix-list prefix-filter-as100 seq 40 permit 203,178.88.0/21 le 24 ip prefix-list prefix-filter-as100 seq 50 permit 178.88.74.0/24 Thank you so much

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bufferbloat videos are up.
by Jim Gettys 04 Feb '12

04 Feb '12

If people have heard of bufferbloat at all, it is usually just an abstraction despite having had personal experience with it. Bufferbloat can occur in your operating system, your home router, your broadband gear, wireless, and almost anywhere in the Internet. Most still think that if experience poor Internet speed means they must need more bandwidth, and take vast speed variation for granted. Sometimes, adding bandwidth can actually hurt rather than help. Most people have no idea what they can do about bufferbloat. So I’ve been working to put together several demos to help make bufferbloat concrete, and demonstrate at least partial mitigation. The mitigation shown may or may not work in your home router, and you need to be able to set both upload and download bandwidth. People like Fred Baker, with fiber to his house and Cisco routers, need not pay attention.... Two of four cases we commonly all suffer from at home are: 1. Broadband bufferbloat (upstream) 2. Home router bufferbloat (downstream) Rather than attempt to show worst case bufferbloat which can easily induce complete failure, I decided to demonstrate these two cases of “typical” bufferbloat as shown by the ICSI data. As the bufferbloat varies widely as theICSI data <http://gettys.files.wordpress.com/2010/12/uplink_buffer_all.png>shows <http://gettys.files.wordpress.com/2010/12/downlink_buffer_all.png>, your mileage will also vary widely. There are two versions of the video: 1. A short bufferbloat video <http://www.youtube.com/watch?v=npiG7EBzHOU>, of slightly over 8 minutes, which includes both demonstrations, but elides most of the explanation. It’s intent is to get people “hooked” so they will want to know more. 2. The longer version of the video <http://www.youtube.com/watch?v=-D-cJNtKwuw>clocks in at 21 minutes, includes both demonstrations, but gives a simplified explanation of bufferbloat’s cause, to encourage people to dig yet further. Best regards, Jim Gettys

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not excactly on-topic Server Cabinet question
by Erik Amundson 04 Feb '12

04 Feb '12

I apologize for this being off-topic in the NANOG list, but I'm hoping some of you have experience with the particulars of what I'm looking for... I am looking for a server cabinet which has an electric latching mechanism on it. I want to use my existing security system and proximity card reader, but have a cabinet door that would open when the card reader is read. Does anyone sell anything like this? I've looked into Rittal, APC, Hoffman, Wrightline (now Eaton), Knurr (via Liebert/Emerson), Middle Atlantic, and Panduit. So far, nothing. Any suggestions? Feel free to reply off-list. - Erik

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AT&T / prodigy.net mail admin
by Robert Glover 04 Feb '12

04 Feb '12

Hello, Can an AT&T mail admin contact me off-list please? I have attempted to get a resolution for an issue through the normal channels and have not gotten anywhere. Sincerely, Bobby Glover Director of Information Services SVI Incorporated

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IPv6 dual stacking and route tables
by -Hammer- 03 Feb '12

03 Feb '12

So, we are preparing to add IPv6 to our multi-homed (separate routers and carriers with IBGP) multi-site business. Starting off with a lab of course. Circuits and hardware are a few months away. I'm doing the initial designs and having some delivery questions with the carrier(s). One interesting question came up. There was a thread I found (and have since lost) regarding what routes to accept. Currently, in IPv4, we accept a default route only from both carriers at both sites. Works fine. Optimal? No. Significantly negative impact? No. In IPv6, I have heard some folks say that in a multi-homed environment it is better to get the full IPv6 table fed into both of your edge routers. Ok. Fine. Then, The thread I was referring to said that it is also advisable to have the entire IPv4 table fed in parallel. Ok. I understand we are talking about completely separate protocols. So it's not a layer 3 issue. The reasoning was that DNS could potentially introduce some latency. "If you have a specific route to a AAAA record but a less specific route to an A record the potential is for the trip to take longer." That was the premise of the thread. I swear I googled it for 20 minutes to link before giving up. Anyway, can anyone who's been thru this provide any opinions on why or why not it is important to accept the full IPv6 table AND the full IPv4 table? I have the hardware to handle it I'm just not sure long term what the reasoning would be for or against. Again, I'm an end customer. Not a carrier. So my concern is (A) my Internet facing applications and (B) my users who eventually will surf IPv6. Any guidance would be appreciated. Thanks. -Hammer- "I was a normal American nerd" -Jack Herer

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This network is too good...
by Robert E. Seastrom 03 Feb '12

03 Feb '12

Hi all, Any thoughts on products that screw up networks in deterministic (and realistic found-in-the-wild) ways? I'm thinking of stuff like PacketStorm, Dummynet, etc. Dial up jitter, latency, tail drop, RED, whatever... (I know someone's gonna say "Just buy a Brand Z FubarSwitch 3k, they will screw up your whole network and you don't even have to configure it to do so!") I'm all-ears like Ross Perot. Thanks, -r

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