Pitfalls of annoucing /24s

Wed Oct 15 21:54:10 UTC 2003

On Oct 15, 2003, at 4:46 PM, Phil Rosenthal wrote:

>
> 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.

Also worth noting that Verio does a loose-rpf check on their borders, 
so there's a possibility your packets will be dropped to multihomed 
customers who *do* have your /24 (if your best-path back to them is via 
verio.)..

>
> --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 at vitalstream.com>
>> To: <nanog at 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.
>
>
>
--
Matt Levine <matt at deliver3.com>
"The Trouble with doing anything right the first time is that nobody 
appreciates how difficult it was."  -BIX