RE: Pitfalls of annoucing /24s

[william () elan net]

Don't know for certain, but I announce from time-time singular /24s out 
of my 64.x block (without announcing entire block, although at times 
I'd announce entire block as two /20s well) and have seen no problems with 
verio or anybody else.

On Wed, 15 Oct 2003, Jean-Christophe Smith wrote:

> I noticed the verio filter policy, in relation to inbound:
>  - In the traditional Class A space (i.e., 0/1), we accept /22 and shorter.
>
> If I want to announce a /24 in the 64.x.x.x space(traditional Class A space)
> am I'm going to have a problem with other networks that have peer filters
> similar to Verios?
>
> Thanks,
> Jean-Christophe Smith
>
> -----Original Message-----
> From: Phil Rosenthal [mailto:pr () isprime com] 
> Sent: Wednesday, October 15, 2003 1:47 PM
> To: John Palmer
> Cc: nanog () merit edu
> Subject: Re: Pitfalls of annoucing /24s
>
>
> http://info.us.bb.verio.net/routing.html#PeerFilter
>
> That's how Verio does it, and I assume, that's how most people who 
> filter by length do it as well.
>
> --Phil
> On Oct 15, 2003, at 4:40 PM, John Palmer wrote:
>
> > Good question.
> >
> > You know there are thousands of legacy /24's out there that were 
> > allocated by
> > IANA as /24's How can you aggregate them up if all you have is the /24?
> >
> > To those who filter out /24's - how is this done - just by the netmask 
> > size?
> >
> > ----- Original Message -----
> > From: "Jean-Christophe Smith" <jsmith () vitalstream com>
> > To: <nanog () merit edu>
> > Sent: Wednesday, October 15, 2003 15:34
> > Subject: Pitfalls of annoucing /24s
> >
> >
> > > In current practice would there be serious jeopardy of portions of the
> > > internet not being able to reach this address space due to bgp 
> > > filters or
> > > other restrictions? What is the smallest acceptable block of IPs that 
> > > can be
> > > announced without adverse or unpredictable results? Verio would most 
> > > likely
> > > be picking up these routes from us. I don't want to cause a religious
> > > debate, but I am interested in what the industry consensus is.
> > >
> > > I'm just doing some research, any comments would be appreciated.
> > >
> > > Thanks,
> > > Jean-Christophe Smith
> --Phil Rosenthal
> ISPrime, Inc.