Re: [OSPF] 答复: 答复: Inconsistency between OSPF extention and IS-IS extension for segment routing

[Peter Psenak <[e-mail]>]

Xiaohu,

there is no LDP in the SR network, so RFC5283 is not applicable.

thanks,
Peter

On 11/7/13 17:28 , Xuxiaohu wrote:
> Hi Peter,
> 
> The 'longest-match algorithm' for LIB installation has been proposed by RFC5283.
> 
> Best regards,
> Xiaohu
> 
> ________________________________________
> 发件人: Peter Psenak [[e-mail]]
> 发送时间: 2013年11月8日 8:39
> 收件人: Xuxiaohu
> 抄送: [e-mail]; [e-mail]
> 主题: Re: 答复: [OSPF] Inconsistency between OSPF extention and IS-IS extension for segment routing
> 
> Xiaohu,
> 
> On 11/7/13 16:23 , Xuxiaohu wrote:
>>
>> Hi Peter,
> ]
>> if you aggregate on area/L1L2 boundary, SIDs/labels for individual
>> prefixes that are covered by the aggregate are useless in the area to
>> which you aggregate - there will be no FIB entries for these individual
>> prefixes in such area. So if you aggregate, there is no need to
>> propagate SIDs/labels for aggregated prefixes.
>>
>> [Xiaohu] "In the multi-area/level
>>      scenario where route summary between areas/levels is required, the IP
>>      longest-match algorithm SHOULD be used by SR-capable routers when
>>      processing label bindings advertised by the mapping server" For more details, please read the Introduction section of http://tools.ietf.org/html/draft-xu-rtgwg-global-label-adv-00
> 
> I don't understand. If you summarize, then only the summary prefix will
> be visible in the backbone (and remote areas) and installed in the FIB
> on all routers in these areas.
> 
> Where would you apply 'longest-match algorithm' when you only see the
> single summary? How would you use the SID/label for prefixes that are
> covered by the summary?
> 
> thanks,
> Peter
>