# A packet of 6,000 Bytes arrives at a router and must be forwarded to a link with an MTU of 1500 bytes.

• How many fragments may be generated? Explain.
• What are the flags and offset values for each fragment, assuming the DF flag was not set, and the IP datagram header is 20 bytes? Show your answer.

Fragment 1: Length=         byte,  D= 0 ,M=   ,      Offset= 0

Fragment 2: Length=          byte,  D= 0 ,M=   ,      Offset=

.....

Fragment N

• When a large datagram is fragmented into multiple smaller datagrams, where are these smaller datagrams reassembled? Explain.

by (user.guest)

When a large datagram is fragmented into smaller datagrams, these smaller data grams are reassembled at the destination, before being passed into the transport layer.

Answer to the first part of the Question;

We have our IP datagram as 6000 Bytes

we have our MTU as = 1500 bytes

We have IP header as 20 bytes

• Now the Size of data that can be transmitted is size of datagram - size of header which is =  6000 - 20 = 5980  bytes
• Now the size of data that can be transmitted in each fragment is = 1500 - 20 = 1480
• The total number of fragments is = 5980/ 1480 which gives us 4.0 fragments.

+1 vote