Re: [sidr] 4-byte vs 2 byte ASN (was re: I-D Action: draft-ietf-sidr-pfx-validate-03.txt)

Pradosh Mohapatra <pmohapat@cisco.com> Wed, 02 November 2011 06:10 UTC

Return-Path: <pmohapat@cisco.com>
X-Original-To: sidr@ietfa.amsl.com
Delivered-To: sidr@ietfa.amsl.com
Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 2F0C311E807F for <sidr@ietfa.amsl.com>; Tue, 1 Nov 2011 23:10:27 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -6.599
X-Spam-Level:
X-Spam-Status: No, score=-6.599 tagged_above=-999 required=5 tests=[BAYES_00=-2.599, RCVD_IN_DNSWL_MED=-4]
Received: from mail.ietf.org ([12.22.58.30]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ags1JAhlv-id for <sidr@ietfa.amsl.com>; Tue, 1 Nov 2011 23:10:25 -0700 (PDT)
Received: from mtv-iport-1.cisco.com (mtv-iport-1.cisco.com [173.36.130.12]) by ietfa.amsl.com (Postfix) with ESMTP id 19B2B11E80B1 for <sidr@ietf.org>; Tue, 1 Nov 2011 23:09:30 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=pmohapat@cisco.com; l=1151; q=dns/txt; s=iport; t=1320214169; x=1321423769; h=subject:mime-version:from:in-reply-to:date:cc: content-transfer-encoding:message-id:references:to; bh=lEJwOoZqhJKRHzOuHSPGwAkWjVBY0BZcwyw6s4oMfLY=; b=IIIlAvvnXiy/aDQ8sL/YxY+JerespgGVY79MaP6iS7AwnxexjAtQTuWO jqZfJ4x+wzj8ge+GtUKarzfR75iVbcjxXfymTfyLzl5qW1DGV2FhWQuZ4 r+rrkS/mA03rHIahZDm6UdoqBA6l+hhjHJXSjymW8QuS7s73d3QNm9BL7 o=;
X-IronPort-Anti-Spam-Filtered: true
X-IronPort-Anti-Spam-Result: Av0EAL/dsE6rRDoG/2dsb2JhbABEqVGBBYFyAQEBAwESASUCPwULC0ZXBjWHYJZgAZ44iCdhBIgGjAuSAQ
X-IronPort-AV: E=Sophos;i="4.69,442,1315180800"; d="scan'208";a="10487727"
Received: from mtv-core-1.cisco.com ([171.68.58.6]) by mtv-iport-1.cisco.com with ESMTP; 02 Nov 2011 06:09:29 +0000
Received: from sjc-vpn5-1887.cisco.com (sjc-vpn5-1887.cisco.com [10.21.95.95]) by mtv-core-1.cisco.com (8.14.3/8.14.3) with ESMTP id pA269TR0021231; Wed, 2 Nov 2011 06:09:29 GMT
Mime-Version: 1.0 (Apple Message framework v1075.2)
Content-Type: text/plain; charset="us-ascii"; format="flowed"; delsp="yes"
From: Pradosh Mohapatra <pmohapat@cisco.com>
In-Reply-To: <DCC302FAA9FE5F4BBA4DCAD4656937791451740474@PRVPEXVS03.corp.twcable.com>
Date: Tue, 01 Nov 2011 23:09:36 -0700
Content-Transfer-Encoding: 7bit
Message-Id: <01D94DBA-0B91-4AA8-9666-A4B22B13FE4A@cisco.com>
References: <20111031182058.24592.70473.idtracker@ietfa.amsl.com> <DCC302FAA9FE5F4BBA4DCAD4656937791451740474@PRVPEXVS03.corp.twcable.com>
To: "George, Wes" <wesley.george@twcable.com>
X-Mailer: Apple Mail (2.1075.2)
Cc: "sidr@ietf.org" <sidr@ietf.org>
Subject: Re: [sidr] 4-byte vs 2 byte ASN (was re: I-D Action: draft-ietf-sidr-pfx-validate-03.txt)
X-BeenThere: sidr@ietf.org
X-Mailman-Version: 2.1.12
Precedence: list
List-Id: Secure Interdomain Routing <sidr.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/sidr>, <mailto:sidr-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/sidr>
List-Post: <mailto:sidr@ietf.org>
List-Help: <mailto:sidr-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/sidr>, <mailto:sidr-request@ietf.org?subject=subscribe>
X-List-Received-Date: Wed, 02 Nov 2011 06:10:27 -0000

> Posing the question about 4-byte ASNs in my review of the BGPSec  
> design reqs draft yesterday makes me wonder about the same in pfx- 
> validate. The draft makes reference to AS_PATH in several locations.  
> I'm thinking that we need a comment early in the draft stating that  
> for the remainder of the draft no distinction is being made between  
> AS_PATH and AS4_PATH, and that this standard is expected to support  
> origin validation of both. Or alternatively, specify that this  
> validation is performed on AS4_PATH and require support for 4893 as  
> a prerequisite for SIDR.
> If we don't explicitly require hosts that support SIDR origin  
> validation to support 4-byte ASN, we may also need some direction  
> regarding specific handling for AS23456, such as to always treat as  
> unknown since there is no way to determine validity for the  
> combination of a prefix and a non-unique placeholder ASN (except for  
> local TA), but we don't necessarily want those routes to be treated  
> as invalid.


I think it's fair to assume that routers supporting origin validation  
also support 4893.

- Pradosh