CS610 Assignment No 4 Solution & Discussion Due Date: 10-01-2012

[fawad]

Q1. If the application selects a datagram size greater than MTU along the path to the destination. How to handle this situation? Illustrate your answer with your own words.

Q2: How can ICMP be used for automated tool and Path discovery? Illustrate your answer with your own words.

[akram ul haq]

kisi ko iss ki ha samajh................pls

[Dream Girl]

Na samjh any wali kon c bat hy is men.. :P   Question tu always samjh ajata hy Solution men tension ho jati hy...lolxxxx

[akram ul haq]

well set.............hahahahahahaha

[Dream Girl]

1st Q to ker lia mene..2nd Half kia hy..koi or b karoo..idea ho kinna theek kia hy mene :D

[+((who am I))+امجد]

the second question is so simple 

you just put a command in your command prompt 

c:/> tracert www.vu.edu.pk

C:\>tracert www.google.com

Tracing route to www.l.google.com [74.125.236.84]
over a maximum of 30 hops:

1 25 ms 29 ms 30 ms 121.52.150.161
2 17 ms 30 ms 28 ms 121.52.150.161
3 3 ms 3 ms 2 ms s11-0-4-0.rwp44d2.pie.net.pk [221.120.235.125]
4 5 ms 12 ms 8 ms rwp44.pie.net.pk [221.120.253.121]
5 27 ms 28 ms 26 ms rwp44.pie.net.pk [221.120.254.38]
6 28 ms 30 ms 28 ms static-khi-ni01-swb.pie.net.pk [202.125.128.142]

7 138 ms 137 ms * 72.14.219.209
8 137 ms 191 ms 139 ms 216.239.43.156
9 138 ms 138 ms 137 ms 209.85.252.194
10 148 ms 187 ms 172 ms 216.239.43.68
11 226 ms 238 ms 223 ms 216.239.46.218
12 242 ms 242 ms 240 ms 209.85.251.9
13 241 ms 259 ms 241 ms 66.249.94.22
14 301 ms 304 ms 296 ms 64.233.174.140
15 290 ms 318 ms 321 ms 64.233.174.177
16 287 ms 286 ms 297 ms 209.85.255.37
17 286 ms 284 ms 295 ms 64.233.175.2
18 285 ms 292 ms 293 ms 66.249.94.93
19 317 ms 317 ms 317 ms 66.249.94.73
20 317 ms 316 ms 315 ms 209.85.249.235
21 321 ms 319 ms 319 ms maa03s05-in-f20.1e100.net [74.125.236.84]

you will get complete path from your computer to the destination . this command used in windows as a tracert and in linux it is usad as traceroot ..,   

how many IP based devices are in the way from source to destination like routers ..

this is ICMP echo used to trace the complete path from source to destination 

[+ M.Tariq Malik +]

CS610 Assignment No 4 Solution Fall 2011

See the attached file please

[+ M.Tariq Malik +]

Assignment Statements:
Q1. If the application selects a datagram size greater than
MTU along the path to the destination. How to handle this
situation? Illustrate your answer with your own words.
Sol:

MTU:
Every hardware technology specification includes the definition of the maximum size of
the frame data area, which is called the Maximum Transmission Unit (MTU). Any
datagram encapsulated in a hardware frame must be smaller than the MTU for that
hardware.
FRAGMENTATION:
One technique is to limit datagram size to smallest MTU of any network. IP uses
fragmentation i.e. datagrams can be split into pieces to fit in network with small MTU.
Router detects datagram larger than network MTU and then it splits into pieces and each
piece is smaller than outbound network MTU.
Each fragment is an independent datagram. It includes all header fields. Bit in header
indicates that the datagram is a fragment. Other fields have information for reconstructing
original datagram. Fragment offset gives original location of fragment.
Router has local MTU to computer size of each fragment. It puts part of data from
original datagram in each fragment and puts other information into header.

[+ M.Tariq Malik +]

Q2: How can ICMP be used for automated tool and Path
discovery? Illustrate your answer with your own words.
Sol:

AN ERROR REPORTING MECHANISM (ICMP)
INTRODUCTION:
IP provides best-effort delivery. Delivery problems can be ignored; datagrams can be
‘dropped on the floor’. Internet Control Message Protocol (ICMP) provides error
reporting mechanism.

INTERNET CONTROL MESSAGE PROTOCOL:
Some errors can be reported. Router sends message back to source in datagram. Message
contains information about problem. It is encapsulated in IP datagram.

USING ICMP TO TEST REACHABILITY:
ICMP can also be used to test different tools. An Internet host A, is reachable from
another host B, if datagrams can be delivered from A to B. Ping program tests reachability.
It sends datagram from B to A, that echoes back to B. it uses ICMP echo request
and echo reply messages. Internet layer includes code to reply to incoming ICMP echo
request messages.

USING ICMP FOR PATH MTU:
Fragmentation should be avoided. Source can configure outgoing datagrams to avoid
fragmentation. Source determines path MTU- smallest network MTU on path from
source to destination. Source probes path using IP datagrams with don’t fragment flag.
Router responds with ICMP fragmentation required message. Source sends smaller
probes until destination reached.

[+ M.Tariq Malik +]

Q1. If the application selects a datagram size greater than MTU along the path to the destination. How to handle this situation? Illustrate your answer with your own words.

Sol:MTU:

Every hardware technology specification includes the definition of the maximum size of
the frame data area, which is called the Maximum Transmission Unit (MTU). Any
datagram encapsulated in a hardware frame must be smaller than the MTU for that
hardware.
FRAGMENTATION:
One technique is to limit datagram size to smallest MTU of any network. IP uses
fragmentation i.e. datagrams can be split into pieces to fit in network with small MTU.
Router detects datagram larger than network MTU and then it splits into pieces and each
piece is smaller than outbound network MTU.
Each fragment is an independent datagram. It includes all header fields. Bit in header
indicates that the datagram is a fragment. Other fields have information for reconstructing
original datagram. Fragment offset gives original location of fragment.
Router has local MTU to computer size of each fragment. It puts part of data from
original datagram in each fragment and puts other information into header.[FONT='Trebuchet MS', Trebuchet, 'Lucida Sans Unicode', 'Lucida Grande', Arial, sans-serif]
[/FONT]
Q2: How can ICMP be used for automated tool and Path discovery? Illustrate your answer with your own words.Sol:AN ERROR REPORTING MECHANISM (ICMP)
INTRODUCTION:
IP provides best-effort delivery. Delivery problems can be ignored; datagrams can be
‘dropped on the floor’. Internet Control Message Protocol (ICMP) provides error
reporting mechanism.INTERNET CONTROL MESSAGE PROTOCOL:
Some errors can be reported. Router sends message back to source in datagram. Message
contains information about problem. It is encapsulated in IP datagram.USING ICMP TO TEST REACHABILITY:
ICMP can also be used to test different tools. An Internet host A, is reachable from
another host B, if datagrams can be delivered from A to B. Ping program tests reachability.
It sends datagram from B to A, that echoes back to B. it uses ICMP echo request
and echo reply messages. Internet layer includes code to reply to incoming ICMP echo
request messages.USING ICMP FOR PATH MTU:
Fragmentation should be avoided. Source can configure outgoing datagrams to avoid
fragmentation. Source determines path MTU- smallest network MTU on path from
source to destination. Source probes path using IP datagrams with don’t fragment flag.
Router responds with ICMP fragmentation required message. Source sends smaller
probes until destination reached.[FONT='Trebuchet MS', Trebuchet, 'Lucida Sans Unicode', 'Lucida Grande', Arial, sans-serif]
[/FONT]

[Jannat Azaan BS(5th sem)]

THANKS A LOTT...

[fawad]

Today is last date of assignment.

[nabeel.ahmed]

Yaar 2nd question ki thek se smj nahi lagi.........Is main sirf ICMP ka intro krwaya hy ye nahi btaya k how can??????