DNS traffic sourced from my address space to myself.

Wed Jul 7 12:07:07 UTC 2010

Howdy,

Recently I have been noticing a good amount of totally bogus DNS traffic coming in on my transit links via my own IP addresses (spoofed). 

SLOT 2:Jul  2 11:26:02 EDT: %SEC-6-IPACCESSLOGP: list 119 permitted udp x.x.145.161(0) -> x.x.145.235(0), 1 packet
SLOT 2:Jul  2 11:26:02 EDT: %SEC-6-IPACCESSLOGP: list 119 permitted udp x.x.146.74(0) -> x.x.145.235(0), 1 packet
SLOT 2:Jul  2 11:26:02 EDT: %SEC-6-IPACCESSLOGP: list 119 permitted udp x.x.146.70(0) -> x.x.145.235(0), 1 packet
SLOT 2:Jul  2 11:26:02 EDT: %SEC-6-IPACCESSLOGP: list 119 permitted udp x.x.146.57(0) -> x.x.145.235(0), 1 packet

There are multiple different instances of this traffic, the pattern seems to be:

-The source is always 'my own IPs' and obviously spoofed.
-It's DNS traffic
-The "source addresses" all seem to be randomly chosen from the same /23 as the destination address (they cycle through randomly).

Has anyone else noticed anything similar coming in on their transit links or am I just lucky?

Normally my iACL catches this but I've just been noticing more of it lately.

-Drew