TCP/IP ????

1
TCP/IP ????

• ? 8? Traceroute ????

2
? ?

• 8.1 ??
• 8.2 Traceroute ???? ??
• 8.3 LAN ??
• 8.4 WAN ??
• 8.5 IP ?? ??? ??
• 8.6 ??

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8.1 ??

• Van Jacobson ??
• ?? ????? ?? ???? ?? IP ?????? ?? ??
• IP ?? ??? ?? ?? ??

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8.2 Traceroute ???? ??

• traceroute? ??? ??
• ?? ???? ??? ??? ??? ???? ?? ?? ??? ??? ??? ??? ?
  ?? ??? ??
• tracerout? ?? ???? ?? ????? ???? ??? ???? ??
• ??? ???? ??? ??
• traceroute ???? UDP ??? ???? ???? ??? ??? ?? ???
  ???? ??
• IP ??? ??? ???? ?? ??? ??
• traceroute? ICMP? IP ??? TTL ?? ??

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8.2 Traceroute ???? ??(contd)

• TTL ?? ??? ??? ?????? ?? ??? ???? ?? ???? ?? ??
• ???? ??? ?? ????? 8?? ??
• ??? ?? 64? ??
• ??? 255
• Hop counter ??? ?? ???? ?? TTL ??? 1? ??
• TTL 0 or 1?? ??? ?? ??
• ??? ????? ICMP time exceeded ???? ??
• ICMP ????? ??? ???? router? IP??? ??

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8.2 Traceroute ???? ??(contd)
Traceroute? ?? ??? ???? TTL? 1? IP ?????? ?? ???
???? TTL? ????? ?????? ???, ICMP ???? ??? ?? ????
??? ??? ?? ??
Traceroute? TTL2? ?? ?? IP ??? ?? ? ??? ????
?????? ?????? ?? ??? ???? ???? ICMP ???? ????
???? ??
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8.2 Traceroute ???? ??(contd)

• ?????? ?? ?? ??.
• ??? UDP ??? ??? ??? ??? ? ??? ???? ???? ? ?? ??.
• ??? ???? UDP ??? ICMP Port unreachable ?? ??
• ICMP ???? Time Exceeded? Port unreachable? ??? ??

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8.3 LAN ??
Traceroute ??
internet
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8.3 LAN ??(contd)

• svr4 traceroute slip
• traceroute to slip (140.252.13.65), 30 hops
  max, 40 byte packets
• 1 bsdi (140.252.13.35) 20 ms 10 ms 10ms
• 2 slip (140.252.13.65) 120 ms 120
  ms 120ms
• ??? ??? IP ??
• 30 hops max TTL30?? ????? ??
• 40 byte packet
• 20 byte IP header
• 8 byte UDP
• 12 byte ??? ???(?????? ??? ??? ??? ????, ??TTL?
  ???, ??? ??? ??? ??? ??)

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8.3 LAN ??(contd)
??? ?? ??? ??? IP?? TTL ?? ?? 3?? ?????? ?? ???
???? ICMP ???? ?? ???? TTL 1 ?? ICMP ???? 20,
10, 10ms TTL 2 ?? ICMP ???? ? 120ms ?????
Traceroute ?????? ?? ?????? RTT ??
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8.3 LAN ??(contd)
1 0.0
who-has bsdi tell svr4 2 0.000586
arprepy bsdi is-at
00c06f2d40 3 0.00.067
svr4.42804 gt slip.33435 udp 12 ttl 1 4
0.004325 bsdigtsvr4
icmptime exceeded in-transit 5
0.069810 (0.0655) svr4.42804 gt slip.33436
udp 12 ttl 1 6 0.071149 (0.0013)
bsdi gtsvr4 icmptime exceeded in-transit 7
0.085162 (0.0140) svr4.42804 gt
slip.33437 udp 12 ttl 1 8 0.086375
(0.0012) bsdi gtsvr4 icmptime exceeded
in-transit 9 0.118608 (0.0322)
svr4.42804 gt slip.33438 udp 12 10
0.226464 (0.1079) bsdi gtsvr4 icmpslip
udp port 33438 unreachable 11 0.287296
(0.0608) svr4.42804 gt slip.33439 udp 12 12
0.395230 (0.1079) bsdi gtsvr4
icmpslip udp port 33439 unreachable 13
0.409504 (0.0143) svr4.42804 gt slip.33440
udp 12 14 0.517430 (0.1079) bsdi
gtsvr4 icmpslip udp port 33440 unreachable
svr4?? slip??? trancetoute? ?? tcpdump
??
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8.3 LAN ??(contd)

• Traceroute? ?? tcpdump? ??
• ??? UDP ??? 33435?? ????, ?????? ?????? 1? ??
• UDP ?????? 12byte ?????? ??
• IP ?????? TTL1? ??? ?? ? ttl1 ??? ??
• ?????? ?? ??? ??? ?? ??
• ?????? ??????? ???? ??? ??
• ICMP Time exceeded ??? ??
• TTL2? 3?? ?????? ??? ???? ???? ICMPPort
  unreachable ??? ??

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8.3 LAN ??(contd)

• Traceroute? ???
• ?? ??? ??? ???? ????? ?? ?? ??? IP ??? ??? ??
  ???? ????? ?? ?? ?? ??
• ????? ???? ??? ???? Traceroute? ??? TTL? ???
  IP??? ???? ???.
• ???? ICMP ???? ?? ??? traceroute? ?? ??? UDP
  ?????? ??? ??? ??? ??
• ??????,??? ?????? ??? ?????? ????? ???? ???? ??.

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8.3 LAN ??(contd)
???? ICMP ???? ??? IP??? ???? UDP ?????? ???
?????? IP??.
Slip traceroute svr4 trcerote to svr4
(140.252.13.30), 30hops max, 40byte packets 1
bsdi (140.252.13.66)110ms 110ms 110ms svr
(140, 252, 13, 34) 110ms 120ms 110ms
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8.3 LAN ??(contd)
????1
if1
????3
if4
????2
???1
???2
if3
if2
Traceroute? ?? ??? ????? ID

• ????1?? ???? 3??? ???? ?? IP??
• if1, if3
• ????3?? ???? 1??? ???? ?? IP??
• if4, if2
• ???? ID
• if2 if3, if1, if4

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8.4 WAN ??
sun traceroute nic.ddn.mil traceroute to
nic.ddn.mil (192.112.36.5), 30 hops max, 40
byte packets 1 netb.tuc.noao.edu
(140.252.1.183) 218 ms 227 ms 233 ms 2
gateway.tuc.noao.edu (140.252.1.183) 233 ms
229 ms 233 ms 3 butch.telcom.arizona.edu
(140.252.104.2) 204 ms 228 ms 234 ms 4
Gabby.telcom.Arizona.EDU (128.196.128.1) 234 ms
228 ms 234 ms 5 NSIgate.telcom.Arizona.ED
U (192.80.43.3) 203 ms 228 ms 234 ms 6
JPL1.NSN.NASA.GOV (128.161.88.2) 234 ms 590
ms 262 ms 7 JPL3.NSN.NASA.GOV
(192.100.15.3) 238 ms 223 ms 234 ms 8
GSFC3.NSN.NASA.GOV (128.161.3.33) 293 ms 318
ms 324 ms 9 GSFC8.NSN.NASA.GOV
(192.100.13.8) 294 ms 318 ms 294 ms 10
SURA2.NSN.NASA.GOV (128.161.88.2) 234 ms 590
ms 262 ms 11 Nsn-FIX-pe.sura.net
(192.80.252.253) 294 ms 318 ms 294 ms 12
GSI.NSN.NASA.GOV (128.161.252.2) 293 ms 318
ms 324 ms 13 NIC.DDN.MIL (192.112.36.5)
324 ms 318 ms 324 ms ??? sun ????
nic.ddn.mil? ?? traceroute
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8.4 WAN ??(contd)

• ??? sun???? ?????(nic)??? ??? ??
• tuc.noao.edu gt telcom.arizona.edu gt
  nsn.nasa.gov gt sura.net gt nic.ddn.mil
• TTL6 ??? RTT 590 ms, ???(234? 262ms) IP
  ???? ???? ??
• TTL 3 ??? RTT 204?? TTL 2 ??? RTT 233
  ?? ??
• ????? ???? ?????? ?? ???? ???

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8.5 IP ?? ??? ??

• Sourse routing? ?? ??
• ???? ??? ??? ??
• source routing? ??
• strict source routing
• ???? IP ??? ??? ???? ??? ??? ??
• ?? ???? ??? ?? ???? ???? ?? ???? ???? ?? ??? ICMP
  source router failed ??? ??
• loose source routing
• ???? ?????? ???? IP ?? ?? ??
• ??? ?? ??? ??? ??? ??? ???? ?? ??? ?? ???? ???? ??

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8.5 IP ?? ??? ??(contd)
39 ???
.
??
??
???
IP ??1
IP ??2
IP ??9
1
1
1
4 ???
4 ???
4 ???
IP header?? source route option? ??

• ?????? IP????? ???? ? ??? ????? ????
  
  
  
  
  ?? ?????. ?? 9???
  ????? ??? ????.
• ????? IP??? ??? IP ?????? ?????? ??.
  
  
  
  
  ??? ???? ???? 9????
  IP??? ??? ???
• IP??? ?? IP??????? ?????? ??
• ??
• 0x83 loose source routing
• 0x89 strict source routing
• ??, ??? RR option? ???

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8.5 IP ?? ??? ??(contd)
?? ??? ?? ?? ?? ??? ?????? ?? ??? ??? ??? ???
???? ????, ?? ???? ???? ??? ???? ??? ??? ??? ???
??? ???? ??, ???? ???? ??? ?? ???? ??
(? ??? ?4) ? ???? ?? ??? ?????? ??? ???? ?? ???
??? ??? ??? ???? ??? ?? ???? ??? ????? ???? ?
???? ?? ??? (1) ??? ?? ?? ??? ??? ??? ???? ?? (2)
?? ?????? ???? IP??? ?? ??? ??? ??? ???? (3) ????
4?? ??
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8.5 IP ?? ??? ??(contd)
??? D R1, R2, R3
??? R1 R2, R3, D
??? R2 R1, R3, D
??? D R1, R2, R3
??? R3 R1, R2, D
s
R1
R2
R3
D
R1
IP?? ???? ?

• ??? ?() 4, 8, 12, 16
• ?? 15(3 ?? IP ?? 3?? ????)

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8.5 IP ?? ??? ??(contd)

• ??? ?????? traceroute ?
• Traceroute? -g ??
• ?????? loose source routing??
• 8??? ????
• ????????? ??? ?? ???????? ? ?? ?? ?????

???? routing?? ?? default route 13 hops, ?? RTT
322 ms loose source routing option 16 hops,
?? RTT 350 ms ??? ??? default route? ? ?? ??
??? ??.
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8.5 IP ?? ??? ??(contd)
Sun tracetoute g 192.31.39.21
nic.ddn.mil traceroute to nic.ddn.mil(192.112.36.5
), 30 hops max, 40 bytes packets 1
netb.tuc.noao.edu(140,252.1.183) 259 ms 256ms
235ms 2 butch.telcom.arizone.edu
(140.252.104.2) 234ms 228ms 234ms 3 Gabby,
Telcom,Arizona.EDU (128.196.128.1) 234ms 257ms
233ms 4 enssl42. UT.westnet.net
(192.31.39.21) 294ms 288ms 295ms 5 t3-2.
Denver-cnss97.t3.ans.net (140.222.97.3) 294ms
288ms 293ms 6 t3-3. Denver-cnss96.t3.ans.net
(140.222.96.4) 294ms 288ms 294ms 7 t3-1.
St-Louis-cnss80.t3.ans.net (142.222.80.2) 294ms
318ms 294ms 8 t3-1. Chicago-cnss24.t3.ans.net
(140.222.24.2) 318ms 295ms 9 t3-2.
Cleveland-cnss40.t3.ans.net (140.222.40.3) 319ms
318ms 324ms 10 t3-1. New-York-cnss32.t3.ans.net
(140.222.32.2) 324ms 318ms 324ms 11 t3-1.
Washington-DC-cnss56.t3.ans.net (140.222.56.2)
353ms 348ms 325ms 12 t3-0. Washington-DC-cnss58
.t3.ans.net (140.222.58.1) 348ms 347ms 325ms 13
t3-0. Enss145.t3.ans.net (140.222.145.1) 353ms
348ms 325ms 14 nsn-FIX-pe.sura.net
(192.80.214.253) 353ms 348ms 325ms 15
GSI.NSN.NASA.GOV (128.161.252.2) 353ms 348ms
354ms 16 NIC.DDN.MIL (192.112.36.2) 354ms 347ms
354ms NSFNET ???? ???
?? ???? ????
nic.ddn.mil? traceroute? ??
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8.5 IP ?? ??? ??(contd)

• ??? ?? ???? trace route ?
• Traceroute? -G ?? ?????? ??
• ???? IP ?????? ???? ??? ?? ??
• ex) sun traceroute -G netb -G
  gateway -G gabby westgate
• traceroute to westgate
  (192.80.43.2), 30 hope max, 40 byte
• packets.
• 1 netb
  (140.252.1.183) 272ms 257ms 26ms
• 2 gateway
  (140.252.1.4) 263ms 259ms 234ms
• 3 gateway
  (140.252.1.4) 263ms !s 235ms !s
  
• ??? ??? ?? ???? traceroute

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8.5 IP ?? ??? ??(contd)
TTL 3 !S ICMP ????? ?? ?? ??? () ??? ??
??? ??? ??, ? gateway?? gabby?? ?? ?? ??? ?? ???
ICMP source route failed ?? ???? ??
??? ?? ???? ??? traceroute ?? A?? B? ??? B?? A??
??? ????? ?? ? ?? ??. ?? ???? ??? ????? ??? ????
?? ???? ?? ??? ?????? ??.
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8.5 IP ?? ??? ??(contd)
Sun traceroute -g bruno.cs.colorado.edu
sun tracerouute to sun (140.252.13.33), 30 hops
max, 40 byte packets 1 netb.tuc.noao.edu
(140.252.1.183) 230ms 227ms 233ms 2
gateway.tuc.noao.edu (140.252.1.4) 233ms 229ms
234ms 3 butch.telcom.arizona.edu
(140.252.104.2) 234ms 229ms 234ms 4
Gabby.Telcom.Arizona.EDU (128.196.128.1) 233ms
231ms 234ms 5 NSIgate.telcom.Arizona.EDU
(192.80.43.3) 294ms 258ms 234ms 6
JPL1.NSN.NASA.GOV (128.161.88.2) 264ms 258ms
264ms 7 JPL2.NSN.NASA.GOV (192.100.15.2)
264ms 258ms 264ms 8 NCAR.NSN.NASA.GOV
(128.161.97.2) 324ms 295ms 9
cu-gw.ucar.edu (192.43.244.4) 294ms 318ms
294ms 10 engr-gw.Colorado.EDU (128.138.1.3)
294ms 288ms 294ms 11 bruno.cs.colorado.edu
(128.138.243.151) 293ms 317ms 294ms 12
engr-gw-ot.cs.colorado.edu (128.138.243.151)
293ms 317ms 294ms 13 cu-gw.Colorado. EDU
(128.138.1.1) 294ms 318ms 294ms 14
enss.ucar.edu (192.43.244.10) 323ms 318ms
294ms 15 t3-1.Denver-cnss97.t3.ans.net
(140.222.97.2) 293ms 288ms 384ms 16
t3-0.enss142..t3.ans.net (140.222.97.2) 293ms
288ms 294ms 17 Gabby.Telcom.Arizona.EDU
(192.80.43.1) 294ms 288ms 294ms 18
Butch.Telcom.Arizona.EDU (128.196.128.88) 293ms
317ms 294ms 19 gateway.tuc.noao.edu
(140.252.104.1) 294ms 289ms 294ms 20
netb.tuc.noao.edu (140.252.1.183) 324ms 321ms
294ms 21 sun.tuc.noao.edu (140.252.13.33)
534ms 529ms 564ms
????? ??? ??? ????
traceroute ?
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8.6 ??
traceroute? TCP/IP ????? ???? traceroute????
?? traceroute? ???? LAN? WAN?? IP ?? ???? ??
IP ???????? strict source routing ? loose source
routing?? ?? ??? ?????? ??? traceroute ??