From: Valdis.Kletnieks@vt.edu
> From: Valdis.Kletnieks@vt.edu
Date: Fri, 03 Dec 2010 20:00:15 -0500
> It is speculated that no later than Q1, two more /8's will be allocated,
> triggering a policy that will give the remaining 5 /8's out to the
> RIR's. That means, prior to end of Q1, the bogon list will be:
>
> 0/8
> 10/8
> 127/8
> 172.16/12
> 192.168/16
> 224/3
Oh. And don't forget to do *bidirectional* filtering of these addresses. 
Ahh, not quite. Blocking 224/3 bi-directionally might cause a few issues
if you accept multicast traffic from anyone.
"Kevin Oberman" <oberman@es.net> writes:
From: Valdis.Kletnieks@vt.edu
> From: Valdis.Kletnieks@vt.edu
Date: Fri, 03 Dec 2010 20:00:15 -0500
> It is speculated that no later than Q1, two more /8's will be allocated,
> triggering a policy that will give the remaining 5 /8's out to the
> RIR's. That means, prior to end of Q1, the bogon list will be:
>
> 0/8
> 10/8
> 127/8
> 172.16/12
> 192.168/16
> 224/3
Oh. And don't forget to do *bidirectional* filtering of these addresses.
Ahh, not quite. Blocking 224/3 bi-directionally might cause a few issues
if you accept multicast traffic from anyone.
You mean like other routers that are speaking OSPF? 
(people should understand the side effects of filtering before they conf t).
-r
From: Valdis.Kletnieks@vt.edu
From: Valdis.Kletnieks@vt.edu
Date: Fri, 03 Dec 2010 20:00:15 -0500
224/3
Oh. And don't forget to do *bidirectional* filtering of these addresses.
Ahh, not quite. Blocking 224/3 bi-directionally might cause a few issues
if you accept multicast traffic from anyone.
240/4 appears to be reserved for "Future use"...
"[15] Reserved for future use (formerly "Class E") [RFC1112]"
Bidirectional blocking of traffic with source addresses in 224/3 -- that should never happen unless I badly misunderstand multicast.
    --Steve Bellovin, http://www.cs.columbia.edu/~smb
If you're smart enough to actually do multicast, you're smart enough to remove
the filter for 224/3. If you're not smart enough to remove the filter, or
you're smart enough but you're one of the 95% that doesn't do multicast, your
site should be doing bidirectional filtering of 224/3.
(Do you really want your users emitting outbound packets to/from 224/3 if you
don't actually do multicast? Probably not...)