IP address reputation, BorderWare

Glenn Steen glenn.steen at gmail.com
Sat Mar 24 15:28:50 CET 2007

On 24/03/07, Res <res at ausics.net> wrote:
> On Fri, 23 Mar 2007, Chris Yuzik wrote:
> > Res wrote:
> >>
> >> It's simple, if anyone is so concerned about a few extra bytes of traffic
> >> in SV, you can solve all of your paranoia simply like this
> >>
> >> telnet core
> >> conf t
> >> access-list 191 deny tcp any any eq 25
> >>
> >> int FastEthernet0
> >> ip access-group 191 in
> >>
> >>
> > Res,
> >
> > Somebody's gonna type that in! Hopefully they won't. But somebody might! Oy!
> Oh yeah, I forgot... If anyones silly enough to type that in without
> knowing what it does, they *deserve* the end result ;)
And that is the reason I dubbed you the evil bunny in the first
place... An evil bunny we like and respect (well, at least I do:-),
but still an evil bunny;-):-).

On the subject, someone (was that Rick? Antoni? don't remember...)
mentioned SAV not being part of the RFCs, which is technically
correct... But AV _is_ part of them... A stupid, useless and unusable
form (VRFY & EXPN), but still part of them. Not that anyone should
have those enabled. Going from that thought to SAV isn't that far a
leap (yeah, I'm playing devils advocate here:-).
Another "devils advocate" perspective... Since we have publicly
available mailservers, conforming to the RFCs (hopefully:-), we _have_
accepted the possibility of someone using the normal SMTP conversation
commands to verify if the sender indeed is a legitimate address (which
is more than an implied requirement in the RFCs, IIRC... always
doubtful, that last bit, so please correct me if I do remember
wrong:), so moaning about the little waste of resources it introduces
becomes ... somewhat ludicrous...

Having said that... For me, recipient verification is far more
important than sender verification... I don't use it simply because
it'd be less than effective, for me/my organization.

But basically I'm with the Evil Bunny on this one;-).

-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se

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