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I am sending UDP packets using ttcp to another machine which is connected via a Cisco router. However, when I analyze the packets sent in Wireshark, there is a UDP packet sent before the payload packets are sent, and 5 packets sent after the payload, which all look like this:

159 841.055676000    UDP 46  Source port: 57128  Destination port: krb524

So when I issue the command:

ttcp -u -t -p 4444 -n 20 -l 1000

The transfer looks like this:

  • 1 Packet sent with Length 46
  • 20 Packets of Length 1046 (as expected)
  • 5 Packets sent with Length 46

What are those additional packets? Do they belong to UDP or is it specific to the ttcp implementation? Thanks

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