計網(wǎng)DHCP報告41212022劉佳樂

1、41212022計算機網(wǎng)絡(luò)實驗報告年級：計算機科學(xué)與技術(shù)一班姓名：劉佳樂 學(xué)號:實驗名稱：wireshark lab:dhcp實驗日期：2014. 12. 11實驗?zāi)康模毫私鈩討B(tài)分配地址的過程實驗器材：安裝wireshark的可以聯(lián)網(wǎng)的電腦實驗步驟：開啟windows命令提示符，輸入：ipconfig /release這個命令釋放你當前的tp地址，因而主機的ip地址就變成了 0. 0. o.oo1. 開啟ethereal network analyzer,開始捕捉數(shù)據(jù)包；2. 現(xiàn)在返回windows命令提示符并輸入：ipconfig /renew這將使你的主機去獲取一個網(wǎng)絡(luò)配置（包括一個新的t

2、p地址）。3等待ipconfig/renew執(zhí)行完畢，然后再次輸入：ipconfig /renew4等第二個ipconfig/rcncw執(zhí)行完畢后輸入命令：ipconfig /release來釋放之前你計算機被分配到的tp地址；5.最后，再次輸入：ipconfig /renew以便再次讓你的計算機分配到ip地址；7 停止數(shù)據(jù)包捕獲。回答以下問題：1. are dhcp messages sent over udp or tcp?答：udprc a a a nc -7c-icri/frir r ncr nr rrr巧 r.»/-r> n一只，-rrj lni圧 frame 27:

3、 342 bytes on wire (2736 bits), 342 bytes captured (2736 bits) on interface 0+ ethernet ii, src: honhaipr_67:65:dd (08:ed:b9:67:65:dd), dst: broadcast (ff:ff汁f:ff汁f:ff)e internet protocol version 4, src: 10.13&97.171 (71), dst: 55 (55)version: 4header length:

4、 20 bytes3 differentiated services field: 0x00 (dscp 0x00: default; ecn: 0x00: not-ect (not ecn-capable transport)total length: 328identification: 0x0686 (1670)e) flags: 0x00fragment offset: 0time to live: 64protocol: udp (17)± header cnecksum: uxueea correctsource: 71 (71

5、)destination: 55 (55)source geoip: unknowndestination geoip： unknown± user datagram protocolf src port: bootpc (68), dst port: bootps (67)£ bootstrap protocol2 draw a timing datagram illustrating the sequence of the first four-packet discover/offer/request/ack dhc

6、p exchange between the client and server. for each packet, indicated the source and destination port numbers. are the port numbers the same as in the example given in this lab assignment?答：與上述實驗屮給出的67, 68端口號一致177 35.527592ooo55 dhcp 342 dhcp discover - transaction id ox372896fdi

7、i aw ve ve ve vme u"tv&u&wv1=耳1134- ii cuuavu ivii av vavf uuvu9<m_+ frame 177: 342 bytes on wire (2736 bits)( 342 bytes captured (2736 bits) on interface 0± ethernet ii, src: liteonte_c2:2d:99 (74:e5:43:c2:2d:99), dst: broadcast (ff:ff:ff汁+ internet protocol version 4, src: 0.0

8、.0.0 (), dst: 55 (55)e user datagram protocol sc port: b?otpc (68), dst port: bootps (67)source port: bootpc (68)oestination port: bootps (67)178 35.64019600055 dhcp 358 dhcp offer transaction id ox372896fd4 iii5 frame 178: 358 bytes on wire (2

9、864 bits), 358 bytes captured (2864 bits) on interface 0s ethernet ii, src: junipern.f7:bo:o9 (a8:d0:e5:f7:b0:09), dst: broadcast (ff:ff:ff:ff:ff:ff)± internet protocol version 4, src: (), dst: 55 (55) 三 usgr datagram protocol, src port: bootps (67

10、), dst port: bootpc (68)source port: bootps (67)destination port: bootpc (68)35.64117900055dhcp356 dhcp request transaction id 0x372896fd |± frame 179: 356 bytes on wire (2848 bits), 356 bytes captured (2848 bits) on interface 0± ethernet ii, src: liteonte_c2:2d:99 (74:e5:43:c

11、2:2d:99), dst: broadcast (ff:ff:ff:ff:ff:ff) ± internet protocol version 4, src: (), dst: 55 (55) ijqar datagram prnr仃廠仃1pcrt： hnptp (68), dst port： bootps (67)source port: bootpc (68)destination port: bootps (67)180 36.14829300055

12、 dhcp 363 dhcp ack - transaction id 0xb72896fde frame 180: 363 bytes on wire (2904 bits), 363 bytes captured (2904 bits) on interface 05 ethernet ii, src: junipern.f7:b0:09 (a8:do:e5:f7:bo:o9), dst: broadcast (ff:ff:ff:ff:ff:ff)± internet protocol version 4, src: (), dst: 2

13、55 (55) c pqpr dazgram prorcrol. 5rr pert: hqzpq (67), dst port： bootpc (68)source port: bootps (67)destination port: bootpc (68)3. what is the link-layer (e.g., ethernet) address of your host?答：主機鏈路層的以太網(wǎng)地址是honhaipr_67:65:dd (08:ed:b9:67:65:dd)。0 frame 27: 342 bytes on wire

14、(2736 bits), 342 bytes captured (2736 bits) on interface 00 ethernet ii, src: honhaipr_67:65:dd (o8:ed:b9:67:65:dd), dst: broadcast£ destination: broadcast (ff:ff:ff:ff:ff:ff)t source: honhaipr_67:65:dd (o8:ed:b9:67:65:dd)type: ip (0x0800)s internet protocol version 4, src: 71 (10.13

15、6.97.171), dst: 55 (255.255.2 0 user datagram protocol, src port: bootpc (68), dst port: bootps (67)0 bootstrap protocol4. what values in the dhcp discover message differentiate this message from the dhcp requestmessage?答：根據(jù)dhcp message type的值加以區(qū)分。160 31.84628200055d

16、hcp347 dhcp request-transaction id 0x67c88689177 35.527592ooo55dhcp342 dhcp discover-transaction id 0x372896fdaflf、a bootstrap protocolmessage type: boot request (1)hardware type: ethernethardware address length: 6hops: 0transaction id： ox372896fde) seconds elapsed: 11田 bootp fla

17、gs: 0x8000 (broadcast)client ip address: ()your (client) ip address: ()next server ip address: ()relay agent ip address: ()client mac address: liteonte_c2:2d:99 (74:e5:43:c2:2d:99)client hardware address padding: 00000000000000000000 server

18、 host name not givenboot file name not givenmaqic cookie: dhcp option: (53) dhcp message typelength: 1dhcp： discover (1)e option: (bl； client ldentirier4 nie bootstrap protocolmessage type: boot request (1)hardware type: ethernethardware address length: 6hops: 0transaction id： ox372896fdq seconds el

19、apsed: 11 bootp flags: 0x8000 (broadcast)client ip address: ()your (client) ip address: ()next server ip address: ()relay agent ip address: ()client mac address: liteonte_c2:2d:99 (74:e5:43:c2:2d:99)client hardware address padding: 00000000

20、000000000000server host name not givenboot file name not givenmagic cookie: dhcpi i option: (5?) ph®tyo©length: 1dhcp： request (3)5. what is the value of the transaction-id in each of the first four (discover/offer/request/ack) dhcp messages? what are the values of the transaction-id in th

21、e second set (request/ack) set of dhcp messages? what is the purpose of the transaction-id field?答：前四個都是0x372896fd ,第二組request/ack dhcp消息中是 0xb75f380d,這個字段的目的是為了區(qū)分每組dhcp的數(shù)據(jù)。177 35.52759200055dhcpj42 dhcp discover - transaction id ox372896fd17835.64019600055

22、dhcp358 dhcp offer-transaction id 0x"2896fd179 35.64117900055dhcp356 dhcp request-transaction id ox372896fd18036.14829300055dhcp363 dhcp ack-transaction id ox?72896fdaw> vi wvvi i wt » w vw www八 awvmv*4918 169.00480000c)55dh

23、cp342 dhcp discover-transaction id oxb75f38od4920 25 .255.255.255dhcp358 dhcp offer-transaction id oxb75f38od4921 169.06995500c25 .255.255.255dhcp356 dhcp request transaction id oxb75f38od4934 174.54317500(25 .255.255.255dhcp356 dhcp request-transaction id oxb75f?8od4935 10.

24、136.0.1174.59397600c55dhcp363 dhcp ack transaction id oxb75f38od6. a host uses dhcp to obtain an ip address, among other things. but a host" s ip address is not confirmed until the end of the four-message exchange! if the ip address is not set until the end of the four-message exch

25、ange, then what values are used in the ip datagrams in the four-message exchange? for each of the four dhcp messages (discover/offer/request/ack dhcp), indicate the source and destination ip addresses that are carried in the encapsulating ip datagram答：客戶機一直以作為自己的原地址，服務(wù)器以響應(yīng)的服務(wù)器地址作為自己的原地址?？蛻魴C與服

26、務(wù)器一直以55最為目的地址。177 o.o.o.o35.52759200055342 dkp discover - transaction id ox372896fd1781-35.6401960002 找 255.255.255dhcp358 dhcp offer transact ion id ox372896fd179 o.o.o.o35.64117900055dhcp356 dhcp request transaction id ox372896fd180 36.148

27、29300055dhcp363 dhcp ack transaction id ox372896fd7. what is the ip address of your dhcp server? 答：我的dhcp服務(wù)器的ip地址是。177 o.o.o.o35.52759200055dhcp342 dhcp discover - transaction id 0x372896fd1178 |35.64019600055dhcp358 dhcp offer transaction i

28、d 0x372896fd179 o.o.o.o35.64117900055dhcp356 dhcp request transaction id ox372896fd180 36.14829300055dhcp363 dhcp ack - transaction id ox372896fd& what ip address is the dhcp server offering to your host in the dhcp offer message? indicatewhich dhcp message co

29、ntains the offered dhcp address答:提供給主機的ip地址是1 o178 35.64019600055 dhcp 358 dhcp offer - transaction id 0x372896f|177 35.527592ooo55 dhcp 342 dhcp discover - transaction id ox372896fi丄transaction id： 0x372896fdseconds elapsed: 0 a bootp flags: 0x8

30、000 (broadcast)your (client) ip address: 16'1369841 (1) intxl sti ver ip dddrsss. 202:覽丹t44.40(202:1 好4軸活mrelay agent ip address: ()client mac address: liteonte_c2:2d:99 (74:e5:43:c2:2d:99)client hardware address padding: 00000000000000000000server host name not givenbo

31、ot file name: bootx86magic cookie: dhcp3 option: (53) dhcp message typelength: 1dhcp： offer (2) option: (1) subnet masklength: 4subnet mask: ()日 option: (58) renewal time valuelength: 4renewal time value: (3600s) 1 hour option: (59) rebinding time value9. in the example screen

32、shot in this assignment, there is no relciy agent between the host and the dhcp server. what values in the trace indicate the absence of a relay agent? is there a relay agent in your experiment? if so what is the ip address of the agent?答：屮介代理的ip地址是o.o.o.o177 35. 52759200055 dhcp

33、 342 dhcp discover - transaction id 0x372896f178 35.64019600055 dhcp 358 dhcp offer - transaction id ox372896fill丄transaction id： 0x372896fdseconds elapsed: 03 bootp flags: 0x8000 (broadcast)client ip address: ()your (client) ip address: 1 (10.136.98.

34、41)next server ip address: 0 (2o2.ll?.144.40)relay agent ip address: ()icli(mt毛電ent住二eihmd30 (749!:c2:2d:99)client hardware address padding: 00000000000000000000server host name not givenboot file name: bootx86magic cookie: dhcp option: (53) dhcp message typelength: 1dhcp

35、： offer (2)3 option: (1) subnet masklength: 4subnet mask: 255. 254.o.o (255.254.o.o)t option: (58) renewal time valuelength: 4renewal time value: (3600s) 1 hour option: (59) rebinding time value10. explain the purpose of the router and subnet mask lines in the dhcp offer message 答：供dhcp用戶在最后收到ack后啟動

36、ip配置時設(shè)置掩碼和網(wǎng)關(guān)。il in the dhcp trace file noted in footnote 2, the dhcp server offers a specific if address to the client (see also question 8 above). in the client，s response to the first server offer message, does the client accept this ip address? where in the client* s response is the client' s requested address?答:1179 35.64117900055 dhcp356 dhcp reiinhardware type: eth