nanog mailing list archives
RE: Pitfalls of annoucing /24s
From: "H. Michael Smith, Jr." <michael () awtechnologies com>
Date: Wed, 15 Oct 2003 17:24:12 -0400
What about the /24's that many ISPs (especially tier 2-3) are assigning to multi-homed customers? What about an IX or "critical infrastructure providers" that may be issued a /24 from ARIN (Policy 2001-3)? Although it may be rare that a large aggregate would become unreachable to a "large" network, doesn't the possibility exist that a customer with a /24 would become unreachable (to some) due to the aggregate dropping out even though the /24 should still be reachable? That scenario may not be very likely, but the question of assymetric routing and one's ability to balance traffic become issues. Assigning a lower preference to /24's would be a lot friendlier than just throwing them away. If I am way off base, I fully expect to be corrected (with volume). My flame retardant suit is in place. Michael -----Original Message----- From: owner-nanog () merit edu [mailto:owner-nanog () merit edu] On Behalf Of Phil Rosenthal Sent: Wednesday, October 15, 2003 4:47 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 /24sIn 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.
Current thread:
- Pitfalls of annoucing /24s Jean-Christophe Smith (Oct 15)
- Re: Pitfalls of annoucing /24s John Palmer (Oct 15)
- Re: Pitfalls of annoucing /24s Phil Rosenthal (Oct 15)
- Re: Pitfalls of annoucing /24s Matt Levine (Oct 15)
- Re: Pitfalls of annoucing /24s Andrew - Supernews (Oct 15)
- Re: Pitfalls of annoucing /24s Phil Rosenthal (Oct 15)
- Re: Pitfalls of annoucing /24s Sean Donelan (Oct 15)
- <Possible follow-ups>
- RE: Pitfalls of annoucing /24s Jean-Christophe Smith (Oct 15)
- RE: Pitfalls of annoucing /24s william (Oct 15)
- RE: Pitfalls of annoucing /24s William Caban (Oct 15)
- RE: Pitfalls of annoucing /24s H. Michael Smith, Jr. (Oct 15)
- Re: Pitfalls of annoucing /24s Phil Rosenthal (Oct 15)
- Re: Pitfalls of annoucing /24s Andy Ellifson (Oct 15)
- Re: Pitfalls of annoucing /24s K. Scott Bethke (Oct 15)
- Re: Pitfalls of annoucing /24s Phil Rosenthal (Oct 15)
- Re: Pitfalls of annoucing /24s John Palmer (Oct 15)
- RE: Pitfalls of annoucing /24s Forrest (Oct 15)
- RE: Pitfalls of annoucing /24s H. Michael Smith, Jr. (Oct 15)
- RE: Pitfalls of annoucing /24s H. Michael Smith, Jr. (Oct 15)
- RE: Pitfalls of annoucing /24s Forrest (Oct 15)
- Re: Pitfalls of annoucing /24s Marshall Eubanks (Oct 18)
- Pitfalls of _accepting_ /24s jlewis (Oct 18)
- RE: Pitfalls of _accepting_ /24s Terry Baranski (Oct 18)
- Re: Pitfalls of annoucing /24s Marshall Eubanks (Oct 18)