Khoa Khoa hc v K thut My tnh i Hc Bch Khoa Tp.HCM

BI THC HNH S 2H tn sinh vin: ......................................................................... Nhm: ..................................MSSV: ........................................... I.

Mc tiu Hiu bit v Ethernet. Hiu bit v ARP. Hiu bit v ICMP.

II.1.

Cc bc thc hinHiu bit v EthernetKhi ng trnh duyt IE hoc Firefox, loi b cc thng tin trong cache: o IE: Tools Internet Options Delete Files

o Firefox: Nhn Ctrl-Shift-Del, chn Cache Loi b vic s dng proxy server nu c th: o IE: Tools Internet Options Connections LAN Settings

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Khoa Khoa hc v K thut My tnh i Hc Bch Khoa Tp.HCM

Khi ng li phn mm Ethereal, bt u tin trnh bt gi. Nhp URL: http://www.cse.hcmut.edu.vn/ vo trnh duyt IE, trang web hin th. Dng li tin trnh bt gi trn Ethereal. Chn Frame cha thng ip HTTP GET. Xem xt thng tin (t chi tit n tng qut) trong Frame trn v tr li cc cu hi sau: o a ch default gateway: ...................................................................................... o Kch thc ca Frame (bytes): ........................................................................... o a ch Ethernet 48-bit ca my tnh bn ang s dng: .................................. o a ch ch 48-bit trong Ethernet frame l g: .................................................... o a ch ch trn l a ch ca my tnh no (www.cse.hcmut.edu.vn hay default gateway): ................................................................................................. o Cc a ch trn c phi l a ch IP khng?...................................................... o Cho bit gi tr thp lc phn ca trng Frame type (2 bytes): ....................... o Cho bit ngha ca trng Frame type:........................................................... o Cho bit c bao nhiu byte k t k t ASCII G trong t kha GET (hay chiu di thng ip tng ng dng): ............................................................. o Hy cho bit s khc nhau gia nh dng ca Ethernet Frame trn so vi nh dng Ethernet Frame hc chng 3 l thuyt: .......................................... Tng t xem xt thng tin (t chi tit n tng qut) trong Frame cha thng ip HTTP response v tr li cc cu hi sau:

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Khoa Khoa hc v K thut My tnh i Hc Bch Khoa Tp.HCM

o o o o

Kch thc ca Frame (bytes): ........................................................................... a ch ch 48-bit c phi l a ch Ethernet my tnh ca bn hay khng? ... a ch ngun 48-bit trong Ethernet frame: ........................................................ a ch ngun trn l a ch ca my tnh no (www.cse.hcmut.edu.vn hay default gateway): ................................................................................................. o Cho bit gi tr thp lc phn ca trng Frame type: ...................................... o Cho bit c bao nhiu byte k t k t ASCII O trong OK: ..........................2.

Hiu bit ARP (Address Resolution Protocol)Xem li l thuyt chng 4, v cc URL sau nm cc thng tin v ARP. o ftp://ftp.rfc-editor.org/innotes/std/std37.txt o http://www.erg.abdn.ac.uk/users/gorry/course/inet-pages/arp.html M DOS prompt, thc hin lnh arp, lnh ny hin th cc thnh phn ca ARP cache trn my tnh ca bn. o Cho bit c php ca lnh arp xem thng tin ARP cache: ........................... o Cho bit ngha ca tng ct trong ARP cache: ............................................... Xa ARP cache bng lnh arp d * Khi ng trnh duyt v loi b cc thng tin trong cache. Khi ng li phn mm Ethereal, bt u tin trnh bt gi. Nhp URL: http://www.cse.hcmut.edu.vn/ vo trnh duyt, trang web hin th. Dng li tin trnh bt gi trn Etherea, lc cc thng ip vi arp. Xem xt thng tin 02 Frame thuc v protocol ARP request v reply, sau tr li cc cu hi sau: o Gi tr thp lc phn ca a ch ngun v ch trong Ethernet Frame ca thng ip ARP request l g: ....................................................................................... o Tm Ethernet Frame bao gm thng ip ARP reply, cho bit gi tr thp lc phn ca a ch ngun v ch, v cho bit l a ch ca my tnh no: ...

3.

Hiu bit v ICMP

a. ICMP v ping Khi ng li phn mm Ethereal, bt u tin trnh bt gi. M DOS prompt v thc hin lnh ping n 10 www.hcmut.edu.vn hoc ping n 10 www.google.com (nu lnh ping www.hcmut.edu.vn tht bi) Sau khi lnh ping kt thc, dng li tin trnh bt gi trn Ethereal. Lc cc thng ip vi icmp. Xem xt thng tin (t chi tit n tng qut) trong cc gi ping trn v tr li cc cu hi sau: o a ch IP my tnh ca bn: ............................................................................... o a ch IP ca website www.hcmut.edu.vn (www.google.com): ........................ o V sao mi ICMP packet khng c ch s port ngun v ch? ......................... o Xem xt mt ICMP packet request, cho bit nh dng ca packet ny: .......... o Xem xt mt ICMP packet reply, cho bit nh dng ca packet ny: .............. b. ICMP v tracert Khi ng li phn mm Ethereal, bt u tin trnh bt gi. M DOS prompt v thc hin lnh tracert www.cse.hcmut.edu.vn hoc tracert www.google.com (nu lnh tracert www.cse.hcmut.edu.vn tht bi). Sau khi lnh tracert kt thc, dng li tin trnh bt gi trn Ethereal. Lc cc thng ip vi icmp. Xem xt thng tin (t chi tit n tng qut) trong cc gi icmp trn v tr li cc cu hi sau: o Cho bit a ch IP ca my tnh c tn l www.cse.hcmut.edu.vn (hoc www.google.com): .............................................................................................. o Cho bit s khc nhau gia gi ICMP ping reply v gi ICMP ping request: ...Trang 3/4

Khoa Khoa hc v K thut My tnh i Hc Bch Khoa Tp.HCM

o Pht tho ng i t my tnh ca bn n www.cse.hcmut.edu.vn(www.google.com): ............................................................................................. --HT--

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