Network Trouble-Shooting Technical Rehearsals Matter! Bob Riddle, Internet 2 14 January 2004
Rehearse, rehearse, & rehearse Questions to answer before opening night • Can I “stretch” the stage from here to there? – do you need a 2 lane road or an expressway? – will you need the highway during rush hour? –do you need to be able to “talk”, “listen”, or both? • Do I live in the right kind of “neighborhood” ? – time to think about FDX, multicast, & switches – time to make some new friends & acquire new toys • What sort of guarantees can I offer my boss?
Stretching the “Stage” Issues to consider when “stretching” the stage • Speed: do you need a freeway, city street, or a dirt road? (mbps) • Latency: is it a “telephone” call or a “movie”? (rtt) • Packet Loss: how much of the content do you care about? (100% … 90% … 50% … 10% …)
Stretching the “Stage” -cont. Plan for a meaningful rehearsal What kind of highway do you need? • • • H. 323 Mpeg 1 Mpeg 2 DV HDTV ~= ~= ~= 384 kbps 1. 5 mpbs 4 – 16 mbps 30 mbps 19. 2 – 270 mbps What kind street do you really need? • One way? (streaming, broadcast) • Two way? (interactive voice & video) • Many way? (more than 2 end points) Do the math! (and budget for the asphalt!)
Rush hour traffic or 3 a. m. traffic? Some lessons learned from the Bing Theater • Good idea - Test early & test often – Sunday evening exercising the network – Monday morning “exercise” – Monday afternoon “exercise” • Result – Hayward suffered from congestion • Lessons learned: – Sun night traffic != to weeknight network traffic – Mon a. m. traffic != to Mon p. m. network traffic it’s important to rehearse the network during show time
You have to live in the Right Neighborhood Take a look at your local neighborhood 1. Run internal tests across your LAN 2. Make sure to test what you hope to use! 3. Find a friend “next door” to test with 4. Learn about ping, traceroute, iperf, Internet 2 Detective, VRVS & what they can tell you 5. Start thinking about what “roads” you’ll need to travel to the next neighborhood(s)
My list or “normal” E 2 E tests Bandwidth tests • iperf (http: //dast. nlanr. net/Projects/Iperf/) – allows for tcp, udp, multicast, bi-directional – allows testing for FDX needs – allows testing at various rates (Kk. Mm) Multicast Tests • iperf (http: //dast. nlanr. net/Projects/Iperf/) • Vic, rat (http: //www. vrvs. org) • in. SORS (http: //internet 2. insors. net) • rc. Bridge (http: //if. anu. edu. au/SW/rcbridge. html)
Use the tools! Results of such tests – NWS example! • bandwidth tests: – discovered DHCP server gateway problem at NWS – discovered 30 mbps with 0% packet loss was the best • FDX testing: – discovered misconfiguration between PC & switch in Ann Arbor Internet 2 office – PC diagnostics said everything was fine, switch display indicated HDX connection to the PC • Human tests: – involve participants in “successful” network testing – need someone with the correct event perspective
Can I buy these tools at Wal-Mart? What did we learn from the Rialto event? • 2 days to learn/fix/configure the network (help!) • What if we could have shipped a no-brainer PC to “almost” endpoint that would all you to remotely exercise all these tools? Introducing the “cakebox” • No operator, no monitor, keyboard, or mouse required • Small, inexpensive, and easy to ship PC • Just plug in a network cable & a power cable • Provide user interface for non-network geeks 8 http: //envoy. internet 2. edu/pioneer/
Tools - cont - http: //detective. internet 2. edu 8 Runs on Windows XP 8 Runs on Mac OSX 8 Runs E 2 E on detective machines 8 Its purpose is to tell you if there is any “hope”!
Other tools you can use 8 http: //e 2 epi. internet 2. edu// 8 http: //www. pingplotter. com/ 8 http: //www. insecure. org/nmap/ 8 http: //www. traceroute. org/ 8 E 2 EP (end-to-end performance group) 8 Questions?
www. internet 2. edu
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