[j-nsp] Output for "show bgp summary" is showing different on two REs

[saurabh sood]

Thanks for this good answer.

Even I was thinking the same but unfortunately when I tried the same on one
of my other router then i saw the following:

Master RE:

{master}
lab> show bgp summary
Groups: 2 Peers: 2 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State
Pending
inet.0                 0          0          0          0
0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last
Up/Dwn State|#Active/Received/Accepted/Damped...
1.1.1.1                 100         11         12       0       0
4:25 0/0/0/0              0/0/0/0
21.1.1.2                300         12         13       0       0
4:43 0/0/0/0              0/0/0/0


Backup RE:

{backup}
lab> show bgp summary
Groups: 2 Peers: 2 Down peers: 0
Table          Tot Paths  Act Paths Suppressed    History Damp State
Pending
inet.0                 0          0          0          0
0          0
Peer                     AS      InPkt     OutPkt    OutQ   Flaps Last
Up/Dwn State|#Active/Received/Accepted/Damped...
1.1.1.1                 100          5          5       0       0
2:00 0/0/0/0              0/0/0/0
21.1.1.2                300          5          5       0       0
2:00 0/0/0/0              0/0/0/0

Please let me know your thoughts about this as it seems to be different what
we think.

Cheers,

Sunny

On Sat, Jun 25, 2011 at 7:39 PM, Stefan Fouant <
sfouant at shortestpathfirst.net> wrote:

> > -----Original Message-----
> > From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-
> > bounces at puck.nether.net] On Behalf Of saurabh sood
> > Sent: Saturday, June 25, 2011 9:41 AM
> > To: juniper-nsp at puck.nether.net
> > Subject: [j-nsp] Output for "show bgp summary" is showing different on
> > two REs
> >
> > Hello,
> >
> > I have observed a different scenario, i don't know wthr it is by
> > expected or
> > not.
> >
> > Router has two REs and GRES, NSR is enabled also commit synchronize is
> > there.
> > But while checking the output for "show bgp summary" then on Master RE
> > everything is showing ok.
> >
> > On the other hand backup RE is showing all bgp states IDLE.
> >
> > Is it an expected behavior?
>
> IIRC, this is normal behavior.  You don't actually want RPD on each
> respective RE attempting to form BGP adjacencies with remote peers at the
> same time.
>
> On the other hand, all the kernel state is replicated - as BGP packets come
> in they are replicated to both REs so that they both have local copies of
> the RIB and based on this should compute identical copies of the FIB
> tables,
> etc. (The reason we don't simply synchronize the state of the Backup RE to
> the Primary is because of Fate Sharing - if there is a problem on the
> Primary you don't want the Backup to be synched and therefore have similar
> problems).
>
> I believe as soon as you perform GRES (or should the Primary fail for some
> reason), the BGP finite state machine should immediately toggle from the
> Idle state to the Established state (or whatever a particular peering state
> happened to be on the Primary RE).
>
> Sorry I don't have more specifics, this is covered in more detail in 'Junos
> High Availability' by James Sonderegger, Orin Blomberg, Kieran Milne, and
> Senad Palislamovic.  This is an excellent book if you want more details
> regarding operations such as the above.
>
> HTHs.
>
> Stefan Fouant
> JNCIE-M #513, JNCIE-ER #70, JNCI
> http://www.shortestpathfirst.net
> GPG Key ID: 0xB4C956EC
>
>