On Wed, Jul 07, 2010 at 08:07:07AM -0400, Drew Weaver wrote:
> 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
>
>
Yeah... I've seen this type of behaviour w/ folks picking random source
addresses
from the IPv6 /32... Sure wish I could announce something smaller.
--bill
