[mdlug] Strange Log Entry

[A. Zimmer]

Hello,

Recently, a strange entry has been occasionally appearing in my kernel
log.  I cannot relate it to any activity that I am doing.  Here is the
entry:

kernel: UDP: bad checksum. From 196.21.79.50:53 to 192.168.0.4:2657 ulen 279

The only thing that changes is the port number on the receiving side
(in this case 2657) and, as best as I can recall, also the originating
address.

My machines are all connected to a router which is in turn connected
to a cable modem.  The address 192.168.0.4 refers not to my Linux
machine but to another computer on my home network which is usually
switched off.

A whois lookup of 196.21.76.50 gives a location in South Africa.

I do not engage in any kind of network activity beyond Internet
surfing and email, so why should this strange message be appearing
in my kernel log?