[j-nsp] 6PE without family inet6 labeled-unicast

[Andrey Kostin]

Hi Pavel, 

Thanks for details. Looks like it's all documented
except next-hop conversion... 

I guess that in "show route
advertised-protocol" the address is shown before conversion because
overwise it would be invalid and could not be announced... 

Kind
regards, 

Andrey 

Pavel Lunin писал 22.07.2018 17:55: 

> Errata 
>>
So your BGP route will not be inactive because of the unreachable
next-hop. 
> So your BGP route *will be* inactive because of the
unreachable next-hop. 
> 
> On Sun, Jul 22, 2018 at 11:52 PM, Pavel
Lunin wrote:
> 
>> On Sun, Jul 22, 2018 at 9:45 PM, Andrey Kostin
wrote:
>> 
>>> Hi Pavel, 
>>> 
>>> Thanks for replying. I understand how
it works as soon as proper next-hop is present in a route. My attention
was attracted by implicit next-hop conversion from pure IPv4 address to
IPv4-mapped IPv6 next-hop from "Nexthop: YYY.YYY.155.141" in the
advertised route to "Protocol next hop: ::ffff:YYY.YYY.155.141" in the
received route.
>> 
>> This is normal. In order to announce AFI/SAFI 2/1
update, you must have an IPv6 next-hop. This is why it gets
automatically converted. If you enable BGP-LU, nothing will change in
this terms, your next-hop address will still be an IPv4-mapped IPv6
address. It will just be labeled. 
>> Same thing happens when you
perform next-hop-self (or it's eBGP) for an IPv6 route, announced via an
MP-BGP session over IPv4. 
>> And ipv6-tunneling under mpls stanza is
what makes your LDP/RSVP routes be leaked from inet.3 to inet6.3 with
automatic v4-to-v6 mapping. It's a syntactic sugar, you can do the same
with policies, explicitly leaking inet.3 to inet6.3.
>> 
>>> I'm also
wondering what could happen is there are no LSP available, which is
rather unreal situation because everything will be broken anyway in this
case.
>> 
>> If no LSP/FEC is available for the v4-mapped IPv6 next-hop,
you won't have an LDP/RSVP route in inet.3, thus it won't be leaked to
inet6.3. So your BGP route will not be inactive because of the
unreachable next-hop. And not, it's not so unusual. You can easily have
your IGP up and running, but someone forgot to add MPLS on one of the
core interfaces. So your BGP session and routes are up, IGP works but
there is no labeled next-hop in inet.3. 
>> -- 
>> Pavel



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