I've been yelling at them about that as well as not being able or willing
to reverse trace spoof attacks. This attack, however, would not have been
stopped by such filters, this is just the address that someone used to
break into a server with.
Thanks for your help.
Brandon Ross Network Engineering 404-815-0770 800-719-4664
Director, Network Engineering, MindSpring Ent., Inc. info@mindspring.com
ICQ: 2269442
Stop Smurf attacks! Configure your router interfaces to block directed
broadcasts. See http://www.quadrunner.com/~chuegen/smurf.cgi for details.
> > 1Cust76.tnt1.sfo2.da.
>
> Id say that looks like uunet. Again. Sigh.
>
> UUnet uses ascend TNT's which they claim you cant filter
> directed-broadcast on. Ive ranted at them since October 20 to get this
> serious security hole closed.
If they can't turn this off on ascend access server, they anyway can
filter out broadcast addresses in their border routers (CISCO's)
forwarding traffic to this access servers. The result is (almost) the
same.
I've been yelling at them about that as well as not being able or willing
to reverse trace spoof attacks. This attack, however, would not have been
stopped by such filters, this is just the address that someone used to
break into a server with.
Thanks for your help.
Brandon Ross Network Engineering 404-815-0770 800-719-4664
Director, Network Engineering, MindSpring Ent., Inc. info@mindspring.com
ICQ: 2269442
Stop Smurf attacks! Configure your router interfaces to block directed
broadcasts. See http://www.quadrunner.com/~chuegen/smurf.cgi for details.
Aleksei Roudnev, Network Operations Center, Relcom, Moscow
(+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 239-10-10, N 13729 (pager)
(+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)
Filtering broadcast addresses is pretty ugly. Consider that a single Class
C broken down into /30's can have 64 broadcast addresses. Maybe if it was
just filtering your own assigned subnets, it would be possible, but this
also applies to customer-subnetted broadcast addresses, so you'd have to
coordinate your filter with every one of your customers, every time they
change subnets. Not impossible, but pretty close.
Pete.
IFF they *only* sub-net into /30's and not have irreguilar sub-nets below
that.
The best I can think of is to just cover your own subnets and let your
down-stream worry about theirs. Otherwise, it's no do-able, like you said.