Speaking of broadcasts, is this a security threat?

[Micah Anderson <micah@riseup.net>]

Every few minutes I see the following show up in my log:

Aug  8 00:03:17 riseup kernel: Packet log: input DENY eth0 PROTO=17
+10.0.0.1:1999 255.255.255.255:1999 L=94 S=0x00 I=638 F=0x4000 T=1 (#4)   
Aug  8 00:49:40 riseup kernel: Packet log: input DENY eth0 PROTO=17   
+10.0.0.1:1999 255.255.255.255:1999 L=94 S=0x00 I=639 F=0x4000 T=1 (#4)
Aug  8 00:03:17 riseup kernel: Packet log: input DENY eth0 PROTO=17
+10.0.0.1:1999 255.255.255.255:1999 L=94 S=0x00 I=638 F=0x4000 T=1 (#4)
Aug  8 00:49:40 riseup kernel: Packet log: input DENY eth0 PROTO=17
+10.0.0.1:1999 255.255.255.255:1999 L=94 S=0x00 I=639 F=0x4000 T=1 (#4)

Now if I interpret this correctly this means that my internal network
interface is broadcasting protocol 1999 (which is like a kerberos thing? I
dont know, I don't have kerberos installed, enabled or anything on my
system) - but it seems to be blasting it out and I am trying to deny
it. Is this actually something on my end that I need to tell to shutup, or
is someone doing this to me? Either one, how can I make it stop??

Thanks!
Micah