計(jì)算機(jī)網(wǎng)絡(luò)管理第四章網(wǎng)絡(luò)測(cè)量和監(jiān)控(編輯修改稿)
2024-10-23 01:18 本頁面
【文章內(nèi)容簡(jiǎn)介】 rosstraffic T1 T0 Size/BW Tn+1 Tn Tn+1 Tn = max(S/BW, T1 – T0) 45 MRTG ? Highly portable SNMP based tool ? Provides only 5 min averages of link utilization ? Used by the work operators only as router SNMP munity string information required ? Linkbylink measurement ? 46 通過端口的流量推測(cè)端到端的流量，發(fā)現(xiàn)流量分布特征 。 47 Pathload ? Sends SelfLoading Periodic Streams at increasing rates till the rate is larger than the tight link available bandwidth and the relative one way delays of packets show an increasing trend. ? This scheme is highly intrusive even though the scheme measures the available bandwidth of the tight link ? Endtoend available bandwidth measurement 48 Measurement tool: PingER ? PingER( Ping Endtoend Reporting ) monitor endtoend performance of Inter links ? /pinger/tools/l 49 路由器流量監(jiān)測(cè) ? 緣由 線速增長(zhǎng)速度遠(yuǎn)遠(yuǎn)高于內(nèi)存訪問速度 不可能對(duì)每個(gè)數(shù)據(jù)包進(jìn)行記錄 必須對(duì)流量進(jìn)行抽樣 ? 問題的關(guān)鍵 如何抽樣 ? 如何將少數(shù)的大流和大量的小流區(qū)分開 對(duì)于網(wǎng)管和計(jì)費(fèi)意義重大 50 Routerbased Passive Measurement 51 NETRAMET METERMIB NeTraMet rulesets meter reader(s) manager analysis application flowdata PME packets (pcap NetFlow LFAP) 52 EXAMPLE OF A RULESET if SourcePeerType == IPv4 { if DestPeerAddress == ( ) { count。 } } 53 MEASURING LIMITS ? WHAT ARE THE LIMITS OF THESE MEASUREMENT TOOLS? CAN, FOR EXAMPLE, SNIFFERS HANDLE MEGABITS OF TRAFFIC? ? Tsinghua CAMPUSNET 20220 USERS 500 Mbps PEAK 54 MEASURING LIMITS CONCLUSIONS ? CURRENT PCs CAN EASILY HANDLE GIGABITS ? WITH SOPHISTICATED NETWORK CARDS SPEEDS OF SEVERAL GIGABITS SEEM POSSIBLE 55 UNIX Command ? SAR System Activity Report, a sampling tool ? ps ? vmstat ? iostat ? stat ? logfiles 56 Commercial Tools ? Netflow（ CISCO） ? ENTERASYS (CABLETRON) ? NetMetrics（ HP OpenView） ? Performance Monitor（ Windows NT） 57 MEASURING TOOLS CONCLUSIONS ? MANY TOOLS EXIST ? SOME ARE COMMERCIAL ? MANY ARE OPEN SOURCE 58 MEASUREMENT RESULTS ? BANDWIDTH CONSUMPTION FOR TOP USERS ? BANDWIDTH CONSUMPTION FOR AVERAGE USERS ? POPULAR PROTOCOLSS / APPLICATIONS（Campus） ? POPULAR PROTOCOLS / APPLICATIONS（Backbone） 59 TOP USERS 60 AVERAGE USERS 61 WHAT STUDENTS DO 0 . 0 0 E + 0 05 . 0 0 E + 0 81 . 0 0 E + 0 91 . 5 0 E + 0 92 . 0 0 E + 0 92 . 5 0 E + 0 93 . 0 0 E + 0 93 . 5 0 E + 0 94 . 0 0 E + 0 94 . 5 0 E + 0 9A l l H T T P K a Z a a N e w s M a i l2 0 0 2 5 2 3 1 8 : 3 52 0 0 2 5 2 4 1 1 : 1 52 0 0 2 5 2 4 1 4 : 0 02 0 0 2 5 2 5 1 1 : 1 52 0 0 2 5 2 5 1 6 : 2 5 62 POPULAR APPLICATIONS（ Backbone） 0102030405060K a Z a a G n u te l l a O th e rP2 PN N T P H T T P F T P SSH G a m e s Ma i l U n k n o w nT e r a o c t e t sG i g a P a c k e t sData collected: 04032022 / 10032022 專題 4：網(wǎng)絡(luò)安全測(cè)量 64 How much security? security convenience 65 Common methods of attack ? password guessing/cracking ? denial of service ? spoofing/masquerading ? buffer overruns ? eavesdropping (sniffing) ? viruses, worm, trojan horses 66 Common scenario of the attack ? find a scanner for latest OS/server vulnerabilities and scan a wide range of address space ? use available exploits to gain access Bugtraq mailing list ? hide yourself on attacked host ? prepa
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