Hi Alia, Shraddha, From: Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> Date: Monday, November 16, 2015 at 1:00 PM To: Shraddha Hegde <shrad...@juniper.net<mailto:shrad...@juniper.net>> Cc: Acee Lindem <a...@cisco.com<mailto:a...@cisco.com>>, OSPF WG List <ospf@ietf.org<mailto:ospf@ietf.org>>, OSPF ADs <ospf-...@tools.ietf.org<mailto:ospf-...@tools.ietf.org>> Subject: Re: [OSPF] Alvaro's DISCUSS on OSPF Admin Tags
Hi Shraddha & Acee, On Mon, Nov 16, 2015 at 12:52 PM, Shraddha Hegde <shrad...@juniper.net<mailto:shrad...@juniper.net>> wrote: Hi Acee/Alia, Pls see inline.. From: Acee Lindem (acee) [mailto:a...@cisco.com<mailto:a...@cisco.com>] Sent: Wednesday, November 11, 2015 2:11 AM To: Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> Cc: Shraddha Hegde <shrad...@juniper.net<mailto:shrad...@juniper.net>>; OSPF WG List <ospf@ietf.org<mailto:ospf@ietf.org>>; OSPF ADs <ospf-...@tools.ietf.org<mailto:ospf-...@tools.ietf.org>> Subject: Re: [OSPF] Alvaro's DISCUSS on OSPF Admin Tags Hi Alia, Shraddha, From: Alia Atlas <akat...@gmail.com<mailto:akat...@gmail.com>> Date: Sunday, November 8, 2015 at 1:59 AM To: Acee Lindem <a...@cisco.com<mailto:a...@cisco.com>> Cc: Shraddha Hegde <shrad...@juniper.net<mailto:shrad...@juniper.net>>, OSPF WG List <ospf@ietf.org<mailto:ospf@ietf.org>>, OSPF ADs <ospf-...@tools.ietf.org<mailto:ospf-...@tools.ietf.org>> Subject: Re: [OSPF] Alvaro's DISCUSS on OSPF Admin Tags Hi Acee, Thanks very much for reading through and pulling out the relevant questions. I'd like to see this conversation resolve quickly. On Sat, Nov 7, 2015 at 9:58 AM, Acee Lindem (acee) <a...@cisco.com<mailto:a...@cisco.com>> wrote: Hi Shraddha, I’ve read through this discussion and I’m wondering why we just can’t remove this normative text with respect to the interpretation of OSPF Node Admin tags? 1. Since the tags are advertised by a single node, why is do they have to be unordered? It seems there should be a reason for this even if this semantic is retained. I can understand this restriction in terms of implementation complexity & assumptions. A router that receives the tag list might want to store them in numerical order or such for easier searching. If the tag order matters, there can be rather different requirements in terms of how the listener uses the information. Perhaps the answer is that we don’t see a use case for maintaining tag order given that they may come from multiple sources it adds a lot of complexity to try and maintain order. Note that the order independence is also in RFC 5130 (IS-IS prefix admin tags) - see section 4. <Shraddha> The restriction of keeping the tag set unordered ensures that the vendor policy implementations will use node tags as a set and not as an ordered list. Since there are no standards defined for policy module, its hard for the operators to guess how the vendor policy implementations behave. I think the explicit mention of the tag ordering ensures there is no ambiguity in interpreting the tags. Ok - this makes sense to me. Let's keep that restriction. I’m ok with this as well. There is precedence with non-order dependence with the IS-IS Admin Tags (Section 4 in RFC 5140). 2. Why can’t they be advertised in multiple flooding scopes? There could be one set of tags applicable at the area scope and another applicable at the AS wide scope. I agree that I don't see implementation complexity logic driving this. Perhaps it allows for storing tags per device in a flat structure instead of requiring that they are stored per area? I wouldn’t think so. Regardless, this feels like it has more impact on operational complexity of having to define the same meaning for different tags for different areas. This restriction of a single flooding scope wouldn’t preclude this. <Shraddha> Tags are independent characteristics of a node. It’s perfectly valid to advertise same tag in different areas so operator need not Define different tags having same meaning for different areas. Since tags are independent characteristics it is well defined whether that characteristic need to be seen by AS wide nodes Or area wide nodes. This sounds like an assumption on the meaning for tags that they won't need to be sent in different scopes. I'm not hearing a strong reason to force this assumption. Let's relax it in the draft. Agreed. If the WG is ok with this resolution, could we get an updated draft this week so I can approve the draft? Sounds good. Thanks, Acee Thanks, Alia Thanks, Acee Regards, Alia In essence, since the tags are purely opaque, it seems you could simply remove the last 2-3 paragraphs of section 3.2.1 and the last paragraph of section 3.2.2 as these seem to be rather arbitrary restrictions. Thanks, Acee _______________________________________________ OSPF mailing list OSPF@ietf.org<mailto:OSPF@ietf.org> https://www.ietf.org/mailman/listinfo/ospf
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