[j-nsp] improving global unicast convergence (with or without BGP-PIC)

[Luis Balbinot]

Even on newer Junos if you don't enable the indirect-next-hop toggle
you'll still see krt entries with 0x2 flags.

On Tue, Apr 18, 2017 at 6:30 PM, Dragan Jovicic <draganj84 at gmail.com> wrote:
> As mentioned on mx trio indirect-nh is enabled and can't be disabled.
> You could check with > show krt indirect-next-hop protocol-next-hop
> commands (0x3 flag should mean it is enabled).
> However this was not the case in older Junos versions where
> indirect-next-hop was in fact not enabled and had to be enabled even on mx
> mpc (it escapes me when was this, pre-13 or so).
>
> If your uplink fails, with indirect-nh change is almost instantaneous,
> given your BGP next-hop is unchanged, as only one pointer needs to be
> rewritten (or you have equal cost uplinks...). However you still need
> composite-next-hop feature for L3VPN labeled traffic and this is NOT
> enabled by default (might be important if you run lots of routes in vrf)...
>
> If your BGP next-hop changes and you have routes in rib (add-paths,
> advertise-external, multiple RRs....), and you have them installed in FT
> (pre- or post- 15.1), you still rely on failure detection of upstream BGP
> router or upstream link (even slower, but you could put upstream links in
> IGP).
>
> There's also egress-protection for labeled traffic..
>
> Before we implemented bgp pic/add-paths, we used multiple RR and iBGP mesh
> in certain parts and spread BGP partial feeds from multiple upstream
> routers to at least minimize time to update FIB, as none of this required
> any upgrade/maintenance.
>
> If you find your FIB update time is terrible, bgp pic edge will definately
> help..
>
> BR,
>
>
> -Dragan
>
> ccie/jncie
>
>
>
>
>
> On Tue, Apr 18, 2017 at 10:07 PM, Vincent Bernat <bernat at luffy.cx> wrote:
>
>>  ❦ 18 avril 2017 21:51 +0200, Raphael Mazelier <raph at futomaki.net> :
>>
>> >> Is this the case for chassis MX104 and 80? Is your recommendation to run
>> >> with indirect-next-hop on them as well?
>> >>
>> >
>> > Correct me if I'm wrong but I think this is the default on all the MX
>> > since a long time. There as no downside afaik.
>>
>> Documentation says:
>>
>> > By default, the Junos Trio Modular Port Concentrator (MPC) chipset on
>> > MX Series routers is enabled with indirectly connected next hops, and
>> > this cannot be disabled using the no-indirect-next-hop statement.
>> --
>> Harp not on that string.
>>                 -- William Shakespeare, "Henry VI"
>> _______________________________________________
>> juniper-nsp mailing list juniper-nsp at puck.nether.net
>> https://puck.nether.net/mailman/listinfo/juniper-nsp
>>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp