kernel way too verbose about eth0

[sumguy231]

Since yesterday, I noticed that about every several seconds or so this shows up in the dmesg output and /var/log/kern.log:

<snip>
Sep  5 20:07:58 formalwear kernel: [422055.557462] Unknown OutputIN= OUT=eth0 SRC=169.254.8.183 DST=169.254.255.255 LEN=176 TOS=0x00 PREC=0x0
0 TTL=64 ID=0 DF PROTO=UDP SPT=631 DPT=631 LEN=156
Sep  5 20:08:11 formalwear kernel: [422068.455796] Unknown OutputIN= OUT=eth0 SRC=169.254.8.183 DST=169.254.255.255 LEN=185 TOS=0x00 PREC=0x0
0 TTL=64 ID=0 DF PROTO=UDP SPT=631 DPT=631 LEN=165
Sep  5 20:08:29 formalwear kernel: [422086.428980] Unknown OutputIN= OUT=eth0 SRC=169.254.8.183 DST=169.254.255.255 LEN=176 TOS=0x00 PREC=0x0
0 TTL=64 ID=0 DF PROTO=UDP SPT=631 DPT=631 LEN=156
Sep  5 20:08:42 formalwear kernel: [422099.430548] Unknown OutputIN= OUT=eth0 SRC=169.254.8.183 DST=169.254.255.255 LEN=185 TOS=0x00 PREC=0x0
0 TTL=64 ID=0 DF PROTO=UDP SPT=631 DPT=631 LEN=165
<snip>

And so on for hundreds of entries. I have a wireless connection on ath0, and I've pretty much never used an ethernet connection with this computer. I guess it's not really hurting anything, but I'm worried about log filesize and the resource overhead of logging this so often.

What's causing it, and can I at least get it to shut up?