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

[Uma Chunduri <[e-mail]>]

Hi Acee,

You asked a good question.

Time and again it's required to identify the node to  establish dynamic connection, without having to worry if the route is hosted by 
the node or not (same properties as of  IS-IS TLV 134 and TLV 140, i.e., routable IP addresses, except not specific to TE)

I can see these -
1.  RLFA TLDP session without having to worry a PQ node supports TE or not
2. Orchestration software on a controller or an application which is having access to 
   the topology database of the network may determine the node IP address without having to go through the hoops (to determine if it's redistributed or leaked etc..)
   with this TLV.


--
Uma C.


-----Original Message-----
From: Isis-wg [mailto:[e-mail]] On Behalf Of Acee Lindem
Sent: Friday, May 09, 2014 5:11 AM
To: Xuxiaohu
Cc: [e-mail]; Wes George; Anton Smirnov; [e-mail]; Joel jaeggli; OSPF List; [e-mail]; [e-mail]
Subject: Re: [Isis-wg] [OSPF] 答复: 答复: [sunset4] IPv6 router IDs

Xiaohu, 

The reason the use case is confusing is that the term L3VPN is commonly used to refer to RFC 4364 VPNs. In your use case, you are hypothesizing something for Segment Routed L3VPNs that I’m not sure is needed with MPLS. Can you add some real use cases to your drafts with justification that it is needed? 

Acee
On May 9, 2014, at 5:31 AM, Xuxiaohu <[e-mail]> wrote:

> Hi Karsten,
> 
> Your understanding is completely correct. 
> 
> Best regards,
> Xiaohu
> 
>> -----邮件原件-----
>> 发件人: Isis-wg [mailto:[e-mail]] 代表 Karsten Thomann
>> 发送时间: 2014年5月9日 16:58
>> 收件人: Xuxiaohu; Anton Smirnov
>> 抄送: [e-mail]; George, Wes; [e-mail]; joel 
>> jaeggli; OSPF List; [e-mail]; [e-mail]
>> 主题: Re: [Isis-wg] [OSPF] 答复: 答复: [sunset4] IPv6 router IDs
>> 
>> Hi Xiaohu,
>> 
>> I think I've understand your problem now, but please don't call it a 
>> Router ID, the router ID must not be an IP address.
>> To avoid any confusion about it please call it a router ip or router 
>> address within the TLV.
>> Please correct me if I'm wrong, but if I understand your drafts right 
>> you're not requesting a real IPv6 Router ID instead of the 
>> (arbitrary) 32bit ID, but a simple TLV to carry the routable IPv6 
>> address of the router which advertises the capability.
>> 
>> If I understand it right, we should maybe fix the text of the other 
>> rfc to refect that it is an routable IP address, instead of a 
>> (possible) arbitrary but unique Router ID.
>> 
>> Kind regards
>> Karsten
>> 
>> Am 09.05.2014 02:53, schrieb Xuxiaohu:
>>> Hi Anton,
>>> 
>>> When ISIS capability TLVs are flooded across areas, routers in one 
>>> area may
>> need to establish correlations between IP 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. When router A needs to send L3VPN traffic to router B via a 
>> MPLS-SR tunnel, router A wants to know whether router B (identified 
>> by an IP address) has the ELC
>> (http://tools.ietf.org/html/draft-xu-isis-mpls-elc-00) before 
>> inserting an EL into the MPLS-SR packet. In such case, it needs to 
>> contain at least one routable IP address in the capability TLV which 
>> has been flooded across area boundaries. In the IPv4 network, the 
>> 4-octect router ID field could contain such routable IPv4 address. 
>> However, in the IPv6 network, there is no counterpart field to contain a routable IPv6 address.
>>> 
>>> Best regards,
>>> Xiaohu
>>> 
>>>> -----邮件原件-----
>>>> 发件人: Anton Smirnov [mailto:[e-mail]]
>>>> 发送时间: 2014年5月8日 22:49
>>>> 收件人: Xuxiaohu
>>>> 抄送: [e-mail]; George, Wes; [e-mail]; joel 
>>>> jaeggli; OSPF List; [e-mail]; [e-mail]
>>>> 主题: Re: [OSPF] 答复: 答复: [Isis-wg] [sunset4] IPv6 router IDs
>>>> 
>>>>     Hello Xiaohu,
>>>>     this whole thread started from George Wes stating that even in 
>>>> pure
>>>> IPv4 world Router ID in many protocols is NOT an IPv4 address. For 
>>>> convenience it frequently is but on the binary scale "ID guaranteed 
>>>> to be routable IPv4 address"/"ID is just a number" - the Router ID 
>>>> is NOT an
>> IPv4 address.
>>>> 
>>>>     So, before you convince people that IPv6 Rtr ID is needed you 
>>>> must start from discussing when and why Router ID is being used as
>>>> IPv4 address in pure
>>>> IPv4 world. I believe this in other words is what Acee asking you.
>>>> 
>>>> Anton
>>>> 
>>>> 
>>>> On 05/07/2014 03:10 AM, Xuxiaohu wrote:
>>>>> Hi Acee,
>>>>> 
>>>>> 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 
>>>> 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 fo
>>>> r router A to know the ELC of router B.
>>>>> Best regards,
>>>>> Xiaohu
>>>>> 
>>>>>> -----邮件原件-----
>>>>>> 发件人: Acee Lindem [mailto:[e-mail]]
>>>>>> 发送时间: 2014年5月6日 21:14
>>>>>> 收件人: Xuxiaohu
>>>>>> 抄送: joel jaeggli; Acee Lindem; George, Wes; [e-mail]; 
>>>>>> OSPF List; [e-mail]; [e-mail]; 
>>>>>> [e-mail]
>>>>>> 主题: Re: [OSPF] 答复: [Isis-wg] [sunset4] IPv6 router IDs
>>>>>> 
>>>>>> 
>>>>>> On May 5, 2014, at 9:48 PM, Xuxiaohu <[e-mail]> wrote:
>>>>>> 
>>>>>>> 
>>>>>>>> -----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.
>>>>>> 
>>>>>> Independent of what you call it, you didn’t answer my question.
>>>>>> Other than TE, what the use cases where it is needed?
>>>>>> 
>>>>>> Acee
>>>>>> 
>>>>>> 
>>>>>>> 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.
>>>>>>>>> 
>>>>>>>>>     -----------
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> --------------------------------------------------------------
>>>>>>>>> --
>>>>>>>>> --
>>>>>>>>> --
>>>>>>>>> --
>>>>>>>>> --
>>>>>>>>> 
>>>>>>>>>     This E-mail and any of its attachments may contain Time 
>>>>>>>>> Warner
>>>> Cable
>>>>>>>>>     proprietary information, which is privileged, confidential, or
>>>>>>>>>     subject to copyright belonging to Time Warner Cable. This
>> E-mail is
>>>>>>>>>     intended solely for the use of the individual or entity to which it
>>>>>>>>>     is addressed. If you are not the intended recipient of this E-mail,
>>>>>>>>>     you are hereby notified that any dissemination, distribution,
>>>>>>>>>     copying, or action taken in relation to the contents of and
>>>>>>>>>     attachments to this E-mail is strictly prohibited and may be
>>>>>>>>>     unlawful. If you have received this E-mail in error, please notify
>>>>>>>>>     the sender immediately and permanently delete the original 
>>>>>>>>> and
>>>> any
>>>>>>>>>     copy of this E-mail and any printout.
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> _______________________________________________
>>>>>>>>> sunset4 mailing list
>>>>>>>>> [e-mail]
>>>>>>>>> https://www.ietf.org/mailman/listinfo/sunset4
>>>>>>>>> 
>>>>>>> _______________________________________________
>>>>>>> OSPF mailing list
>>>>>>> [e-mail]
>>>>>>> https://www.ietf.org/mailman/listinfo/ospf
>>>>> _______________________________________________
>>>>> OSPF mailing list
>>>>> [e-mail]
>>>>> https://www.ietf.org/mailman/listinfo/ospf
>>>>> 
>>> _______________________________________________
>>> OSPF mailing list
>>> [e-mail]
>>> https://www.ietf.org/mailman/listinfo/ospf
>> 
>> _______________________________________________
>> Isis-wg mailing list
>> [e-mail]
>> https://www.ietf.org/mailman/listinfo/isis-wg
> _______________________________________________
> Isis-wg mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/isis-wg

_______________________________________________
Isis-wg mailing list
[e-mail]
https://www.ietf.org/mailman/listinfo/isis-wg