UDP with wrong checksum and ICMP messaging

[dms5]

I have a question regarding UDP datagrams and checksum. If a UDP packet arrives with a wrong checksum and the receiver replies to the sender with a ICMP error message that holds 28 bytes (20 for IP header and 8 byte UDP header), can the sender then use that info and guess what UDP packet was bad and resend that packet?

 

[burtsbees]

No---UDP packets are not connection-oriented and have no sequence numbers. The UDP packets are not resent.

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!

 

[dms5]

Thanks for the clarification burtsbees...

 

[jimbopalmer]

I would have said "Tracking and resending lost UDP frames is up to the application, not the protocol." But most applications do not track or resend frames, so Burtsbees is right, at least most of the time

I tried to remain child-like, all I acheived was childish.

 

[burtsbees]

Thanks, Jimbo---I try not to be right all the time on purpose, because then people would start praying to me...

lol

/

tim@tim-laptop ~ $ sudo apt-get install windows
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Couldn't find package windows...Thank Goodness!