[Isis-wg] 答复: [sunset4] IPv6 router IDs

[Xuxiaohu <[e-mail]>]

> -----邮件原件-----
> 发件人: Isis-wg [mailto:[e-mail]] 代表 joel jaeggli
> 发送时间: 2014年5月5日 23:55
> 收件人: Acee Lindem; Xuxiaohu; George, Wes
> 抄送: [e-mail]; [e-mail]; [e-mail];
> [e-mail]; [e-mail]
> 主题: Re: [Isis-wg] [sunset4] IPv6 router IDs
> 
> On 5/5/14, 9:28 AM, Acee Lindem wrote:
> > Xiaohu – what are precisely the situations that you think you need
> > this
> > IPv6 address?
> > Acee
> 
> if you're using router-id's as equivalency as an ipv4 unicast addresses.
> you're doing so at your peril because there is zero assurance that those actually
> map. the first time you have a router id of
> 11100000000000000000000000000101 well bummer.

The IPv6 router ID sub-TLV of the ISIS router capability TLV must carry a "routable" IPv6 address. If the name of the sub-TLV seems confusing, it can be changed to IPv6 address sub-TLV.

Best regards,
Xiaohu

> I don't find the embedding of semantic meaning in router-ids to be more
> compelling then it was in ip addresses.
> 
> > From: Xuxiaohu <[e-mail] <mailto:[e-mail]>>
> > Date: Sunday, May 4, 2014 1:29 AM
> > To: "George, Wes" <[e-mail]
> > <mailto:[e-mail]>>
> > Cc: OSPF - OSPF WG List <[e-mail] <mailto:[e-mail]>>,
> > "[e-mail] <mailto:[e-mail]>" <[e-mail]
> > <mailto:[e-mail]>>, "[e-mail]
> > <mailto:[e-mail]>" <[e-mail]
> > <mailto:[e-mail]>>, "[e-mail]
> > <mailto:[e-mail]>" <[e-mail]
> > <mailto:[e-mail]>>, "[e-mail]
> <mailto:[e-mail]>"
> > <[e-mail] <mailto:[e-mail]>>
> > Subject: Re: [Isis-wg] [sunset4] IPv6 router IDs
> >
> >     Hi Wes,
> >
> >
> >
> >     Thanks for pointing out these two drafts.
> >
> >
> >
> >     The motivation for these two drafts
> >     (http://tools.ietf.org/html/draft-xu-isis-ipv6-router-id-00 and
> >     http://tools.ietf.org/html/draft-xu-ospf-ipv6-router-id-00) is very
> >     simple: the IPv6 ISIS|OSPF capability TLV/RI-LSA which are used for
> >     advertising router capabilities can be flooded across areas,
> >     however, only a 4-octect router ID is carried in them. As a result,
> >     it’s hard for routers in one area to establish correlations between
> >     IPv6 addresses and capabilities of routers in another area. For
> >     example, assume IS-IS router A in one area has established a L3VPN
> >     session with IS-IS router B in another area over their own IPv6
> >     addresses. When router A needs to send L3VPN traffic to router B via
> >     a MPLS-SR tunnel, router A wants to know whether router B has the
> >     ELC (http://tools.ietf.org/html/draft-xu-isis-mpls-elc-00) before
> >     <http://tools.ietf.org/html/draft-xu-isis-mpls-elc-00)%20before>
> >     inserting an EL into the MPLS-SR packet . However, the Capability
> >     TLV originated by router B doesn’t carried an IPv6 address of its
> >     own. As a result, it’s hard for router A to know the ELC of router B.
> >
> >
> >
> >     Best regards,
> >
> >     Xiaohu
> >
> >
> >
> >     *发件人:*George, Wes [mailto:[e-mail]]
> >     *发送时间:*2014年5月2日1:51
> >     *收件人:*Xuxiaohu
> >     *抄送:*[e-mail] <mailto:[e-mail]>;
> >     [e-mail] <mailto:[e-mail]>;
> >     [e-mail] <mailto:[e-mail]>
> >     *主题:*Re: [sunset4] IPv6 router IDs
> >
> >
> >
> >     I got a bounce-back on all 3 draft aliases, trying again with the
> >     authors’s email addresses directly.
> >
> >
> >
> >     *From: *<George>, "George, Wes" <[e-mail]
> >     <mailto:[e-mail]>>
> >     *Date: *Thursday, May 1, 2014 at 1:42 PM
> >     *To: *"[e-mail]
> >     <mailto:[e-mail]>"
> >     <[e-mail]
> >     <mailto:[e-mail]>>,
> >     "[e-mail]
> >     <mailto:[e-mail]>"
> >     <[e-mail]
> >     <mailto:[e-mail]>>
> >     *Cc: *"[e-mail]
> >     <mailto:[e-mail]>"
> >     <[e-mail]
> >     <mailto:[e-mail]>>,
> >     "[e-mail] <mailto:[e-mail]>" <[e-mail]
> >     <mailto:[e-mail]>>
> >     *Subject: *[sunset4] IPv6 router IDs
> >
> >
> >
> >     I see that you have submitted two drafts for IPv6 router IDs in ISIS
> >     and OSPF, noting that the existing router ID is only 4 octets. This
> >     has also come up in IDR for BGP. The authors of that draft are
> >     copied. I’ll give you a similar set of feedback to what I gave
> > them -
> >
> >
> >
> >     It is important to distinguish between places where a unique
> >     identifier is needed, and by *convention* an IPv4 address assigned
> >     to the device has been used to provide that unique ID, vs. places
> >     where the actual IP address has some sort of importance to the
> >     protocol (I.e. That information must be available to take action on).
> >
> >     In other words, is the protocol requirement that the ID be unique
> >     across some domain, but that the actual value does not matter, or is
> >     the protocol requirement that the value must correspond to something
> >     on the router? In many of the former cases, the fact that the value
> >     isn’t relevant has been used to make recommendations that are easier
> >     for humans to deal with (I.e. Tying the router ID to an IP address)
> >     but that value as a human-readable set of info does not necessarily
> >     justify  changes to the protocol to support that convention as we
> >     move to IPv6.
> >
> >     I would argue that the router ID used in routing protocols must
> >     merely be unique, but it doesn’t have to be an IP address at all.
> >     Thus it is not strictly necessary to create a new field to carry
> >     IPv6 addresses when operating without IPv4 addresses on a network.
> >     If you believe otherwise, the justification needs to be documented
> >     in the draft.
> >
> >
> >
> >     There are many places in IETF protocols where a 32 bit unique
> >     identifier is needed, and by convention an IPv4 address has been
> >     used. It would be far more useful to write a general draft
> >     identifying this problem and discussing several solutions, including
> >     simply generating unique IDs manually, systematically generating a
> >     random ID, etc.  the place for such a draft may be in Sunset4,
> >     either as a part of the existing gap analysis draft or as another
> >     standalone draft.
> >
> >
> >
> >     There was rather a long discussion about this on IDR, thread
> >     here:
> > https://mailarchive.ietf.org/arch/search/?qdr=a&email_list=idr&q=%22%5
> > Bidr%5D+%5Bv6ops%5D+BGP+Identifier%22&as=1&gbt=1
> >
> >
> >
> >     And in the IDR meeting, minutes:
> >
> >     http://www.ietf.org/proceedings/89/minutes/minutes-89-idr (see
> > page 11)
> >
> >
> >
> >     I’d encourage the authors of these drafts to work together on this.
> >
> >
> >
> >     Thanks,
> >
> >
> >
> >     Wes George
> >
> >
> >
> >     Anything below this line has been added by my company’s mail server,
> >     I have no control over it.
> >
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> >
> >
> >
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