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Showing posts from February 22, 2009

Cisco IOS causes Internet disruption

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在Internet上每一個AS(Autonomous System自治系統,如:一家ISP/固網業者/網路組織)都是組成Internet的一部份,只要一個AS BGP出錯就有可能造成Internet無法正常運作,2009/02/16就發生了一個很經典的錯誤 - 因為某ISP宣告的BGP AS-Path Prepend過長,導致全世界的網路只要有使用Cisco Router的AS都出現網路中斷的情況,因為Cisco IOS無法處理直接Reset BGP neighbor…所以明智的老闆們請不要吝惜於員工培養的教育訓練,小小的教育訓練成本有可能可以挽救全世界~ Cisco IOS causes Internet disruption Author: Fabio Semperboni Feb.24, 2009 in Stories On February 16th, SuproNet , a local Czech provider, single-handedly caused a global Internet meltdown for upwards of an hour today. SuproNet accomplished this feat by sending out a rather unusual routing update, one which a lot of routers did not handle very well. The result was Internet bedlam. “What we think happened next is the Internet equivalent of a massive buffer overflow . While most of the core routers run by major ISPs fared just fine, processing the ridiculous path and sending it on, others choked. Perhaps they weren’t as well maintained or were running buggy software. These routers viewed the up

Cisco專業認證介紹(updated on 02/23/2009)

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昨天應Cisco邀請協助到CHT去介紹目前Cisco認證所有Track的現況及相關課程。我想這份資料對許多不了解Cisco認證的人都或多或少有所幫助,因此我把這份文件放到 Scribd 供各位下載參閱,如有任何不清楚或是其他更好的建議也歡迎給我批評及指教。 Cisco專業認證介紹 Publish at Scribd or explore others: Business Presentations & Slid ccna CCNP