I do believe, as has been pointed out to me elsewhere that this is what shows up when there's a 64 bit ASN and router software that doesn't grok 64 bit ASNs
So, completely by chance that one such as belongs to what looks like a bulk mailer --srs (htc one x) On 03-Feb-2013 9:02 PM, "Dave Pooser" <[email protected]> wrote: > On 2/3/13 9:04 AM, "Rich Kulawiec" <[email protected]> wrote: > > >On Sun, Feb 03, 2013 at 06:12:32PM +0530, Suresh Ramasubramanian wrote: > >> AS23456 is currently announcing a good few netblocks (which don't have a > >> very good smtp reputation, by the way). > > > >To say the least. A quick rDNS scan reveals that those netblocks include: > > > > 8448 addresses > > 6932 return nxdomain > > 512 return servfail > > 1004 with rDNS entries > > > >Those 1004 hosts with rDNS account for 36 domains: > > <snip long list of spammy domains> > > Just as another data point, the domain names you listed hit on enough URL > blacklists that Spamassassin quarantined the message for me (and would > have rejected it during the SMTP transaction had the NANOG server not been > listed on DNSWL-High). Spam hosts plus fake ASN = paging the Spamhaus DROP > maintainers to the white courtesy phone.... > -- > Dave Pooser > Manager of Information Services > Alford Media http://www.alfordmedia.com > > > >
