Pitfalls of annoucing /24s

Marshall Eubanks tme at multicasttech.com
Thu Oct 16 16:30:30 UTC 2003


Hello;

On Wednesday, October 15, 2003, at 11:57 PM, Forrest wrote:

>
>
> True enough, but are there any providers currently that filter /24's 
> from
> the old Class C space that /24's were assigned directly from?
>

As someone who is multihomed but uses others /24's, I am sensitive to
this.

I do not _think_ that any major provider filters on /24's now - but it's
fairly common to filter on /25 and longer.


> I realize that if proposal 2002-3 does get passed but everyone filters
> those prefixes then it will be a completely worthless proposal, and 
> even
> worse than using PA space.
>

I had good luck contacting the ISP's that were filtering and asking them
nicely not to. I think that providers will mostly follow ARIN's lead.


> It seems to me that proposal 2002-3 could enable providers to filter 
> more
> efficiently however.  They could accept the long prefixes out of the
> micro-assignment block, while filtering out all the garbage /24's in 
> the
> other space caused by people needlessly announcing every /24 out of 
> their
> large aggregate.
>

I would agree.

> Forrest
>

Regards
Marshall Eubanks

> On Wed, 15 Oct 2003, Andrew Dul wrote:
>
>> Forrest,
>>
>> Even if ARIN passes this policy that will not make any provider change
>> their filtering policy.  It is true that many providers do use the 
>> ARIN
>> allocation sizes to create their filtering rules but the two are not
>> inherently linked.  Any ASN can choose the filter on what ever rule 
>> set
>> they choose.
>>
>> Andrew
>>
>
>
                                  Regards
                                  Marshall Eubanks

T.M. Eubanks
e-mail : tme at multicasttech.com
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