Re: Gen-ART review of draft-ietf-ospf-dynamic-hostname-03
"Spencer Dawkins" <spencer@wonderhamster.org> Fri, 12 June 2009 10:25 UTC
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From: Spencer Dawkins <spencer@wonderhamster.org>
To: "Sanjay Harwani (sharwani)" <sharwani@cisco.com>, Subbaiah Venkata <svenkata@google.com>, Danny McPherson <danny@tcb.net>, "Carlos Pignataro (cpignata)" <cpignata@cisco.com>
References: <CA58015D3E7448B79071CC084809C49A@china.huawei.com> <2D9DC4E509A67045894D4EA745FCA398517C90@XMB-BGL-416.cisco.com>
Subject: Re: Gen-ART review of draft-ietf-ospf-dynamic-hostname-03
Date: Fri, 12 Jun 2009 05:24:26 -0500
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Cc: Ross Callon <rcallon@juniper.net>, General Area Review Team <gen-art@ietf.org>, "Abhay Roy (akr)" <akr@cisco.com>, ietf@ietf.org, Acee Lindem <acee@redback.com>
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Hi, Sanjay, please see inline starting with SD: And thanks for a quick response (before I leave for vacation today). Spencer ----- Original Message ----- From: "Sanjay Harwani (sharwani)" <sharwani@cisco.com> To: "Spencer Dawkins" <spencer@wonderhamster.org>; "Subbaiah Venkata" <svenkata@google.com>; "Danny McPherson" <danny@tcb.net>; "Carlos Pignataro (cpignata)" <cpignata@cisco.com> Cc: <ietf@ietf.org>; "General Area Review Team" <gen-art@ietf.org>; "Ross Callon" <rcallon@juniper.net>; "Acee Lindem" <acee@redback.com>; "Abhay Roy (akr)" <akr@cisco.com> Sent: Thursday, June 11, 2009 11:38 PM Subject: RE: Gen-ART review of draft-ietf-ospf-dynamic-hostname-03 Adding in Carlos who holds the pen for us, Please see inline starting with SH: -----Original Message----- From: Spencer Dawkins [mailto:spencer@wonderhamster.org] Sent: Friday, June 12, 2009 3:55 AM To: Subbaiah Venkata; Sanjay Harwani (sharwani); Danny McPherson Cc: ietf@ietf.org; General Area Review Team; Ross Callon; Acee Lindem; Abhay Roy (akr) Subject: Gen-ART review of draft-ietf-ospf-dynamic-hostname-03 I have been selected as the General Area Review Team (Gen-ART) reviewer for this draft (for background on Gen-ART, please see http://www.alvestrand.no/ietf/gen/art/gen-art-FAQ.html). Please resolve these comments along with any other Last Call comments you may receive. Document: draft-ietf-ospf-dynamic-hostname-03 Reviewer: Spencer Dawkins Review Date: 2009-06-11 IETF LC End Date: 2009-06-16 IESG Telechat date: (not known) Summary: This document is almost ready for publication as a Proposed Standard. I identified two minor issues listed below. 2. Possible solutions Another approach is having a centralized location where the name-to- Router ID mapping can be kept. DNS can be used for the same. A disadvantage with this centralized solution is that its a single Spencer (nit): s/its/it's/ point of failure; and although enhanced availability of the central mapping service can be designed, it may not be able to resolve the hostname in the event of reachability or network problems. Also, the response time can be an issue with the centralized solution, which can be particularly problematic in times of problem resolution. If Spencer (minor): good point on response times, but I'd also think you'd point out that looking up attributes on a centralized mapping table is exactly the wrong thing to do when you're resolving problems with routing - the centralized resource may not even be reachable. SH: I think we already have it covered just above in the same paragraph. (single point of failure) <snip> A disadvantage with this centralized solution is that its a single point of failure; and although enhanced availability of the central mapping service can be designed, it may not be able to resolve the hostname in the event of reachability or network problems. </snip> SD: I'll call for my eye exam appointment when they open :-). What I liked about the response time text was that it clearly called out the impact on problem resolution - if it was possible for this to be clearly stated for reachability, that seems helpful to me. If I was suggesting text, it might be something like: SD: A disadvantage with this centralized solution is that it's a single point of failure; and although enhanced availability of the central mapping service can be designed, it may not be able to resolve the hostname in the event of reachability or network problems, which can be particularly problematic in times of problem resolution. Also, the response time can be an issue with the centralized solution, which can be equally problematic. 3. Implementation The Dynamic Hostname TLV (see Section 3.1) is OPTIONAL. Upon receipt of the TLV a router may decide to ignore this TLV, or to install the symbolic name and Router ID in its hostname mapping table. Spencer (minor): I'm suspecting that if this attribute becomes widely deployed, network operators would train themselves to read the hostname and pay very little attention to the numeric router ID, so I'm wondering if it's worth saying anything (either here or in an Operations and Management Considerations section <ducks> :-) about the possibility that two different routers may both insist they are "routerXYZ". That would be a misconfiguration, and the text as written allows the router to ignore the second attempt to claim the name "routerXYZ", but it would be irritating to troubleshoot a problem looking at logs that conflate two disjoint "routerXYZ" routers. I'm not a router guy, so I don't know what other responses might be appropriate - I don't think you'd declare an error for a perfectly good next-hop who's confused about its hostname, and I don't know if suggesting that this be SNMP TRAPped would make sense - but you guys would be the right ones to suggest an appropriate response. SH: This is a mis-configuration issue. Network Administrators need to be careful while configuring hostnames on the routers. I think we have text around this in <snip> 5. Security Considerations Since the hostname-to-Router ID mapping relies on information provided by the routers themselves, a misconfigured or compromised router can inject false mapping information. </snip> However I am open to the idea of elaborating it somewhere else too if every body else feels its needed. SD: I actually saw THAT text :-). I was hoping for an explicit mention of the possibility that two routers might both insist they had the same hostname. the beautiful thing about last call comments is that you guys get to do the right thing. Regards Sanjay
- Gen-ART review of draft-ietf-ospf-dynamic-hostnam… Spencer Dawkins
- RE: Gen-ART review of draft-ietf-ospf-dynamic-hos… Sanjay Harwani (sharwani)
- Re: Gen-ART review of draft-ietf-ospf-dynamic-hos… Spencer Dawkins
- Re: Gen-ART review of draft-ietf-ospf-dynamic-hos… Carlos Pignataro
- Re: Gen-ART review of draft-ietf-ospf-dynamic-hos… Spencer Dawkins
- Re: Gen-ART review of draft-ietf-ospf-dynamic-hos… Carlos Pignataro