[j-nsp] Graceful restart & Graceful switchover

[William Phang]

Hi Hemant,

Actually, it is depend on your network topology. If you are only using 1
router then you don't need to enable graceful-restart for all protocols.

Suppose that you have the topology like below:

R1---R2----R3

And You want to do a graceful-switch-over RE on R2, then you need to enable
graceful-restart for the protocols that running on the boxes, like IGP,
MPLS, RSVP, etc. If the graceful-restart is working, when you do remove
master RE, then the protocol state will change to down. But with
Graceful-restart, it will tell to the neighbor routers, it is going to down,
but please continue forwarding to me, so the traffic will be continue
forwarding to the R2. 

If you don't enable Graceful-restart, when you remove master RE, the
protocols will be down, so the neighbor router will not forward traffic to
R2, so all traffic is dropped until the protocols come up.

I have tested this scenario on M10i, M40e, and M320 without packet drop.

You should never see the FPC reboot if you remove master RE or switch the RE
to the backup one. 


Regards,

William


-----Original Message-----
From: Hemant Narkhede [mailto:hemantn at houstontechnologies.com] 
Sent: Sunday, June 05, 2005 8:51 PM
To: 'William Phang'; gtate at juniper.net
Cc: juniper-nsp at puck.nether.net; pekkas at netcore.fi
Subject: RE: [j-nsp] Graceful restart & Graceful switchover

 
Hi Wlliam,

But do u think enabling Graceful restart for all protocols going to affect
routers RE's graceful switchover process ?

When I switch from RE 0 to RE 1 failover works fine. But when switch from RE
1 to RE 0 then all FPC reboots. That means switchover takes place
successfully but packet drop will be there since FPC rebooting/initialising.

Still I will check this & get back to you,

Thanks & Regards,

Hemant N.

-----Original Message-----
From: William Phang [mailto:phangjk at hotpop.com] 
Sent: Monday, June 06, 2005 9:05 AM
To: hemantn at houstontechnologies.com; gtate at juniper.net
Cc: juniper-nsp at puck.nether.net; pekkas at netcore.fi
Subject: RE: [j-nsp] Graceful restart & Graceful switchover

I think you may need to delete the "failover on-loss-of-keepalives".

The following config which I have tested with zero packet loss:

chassis {
    redundancy {
        routing-engine 0 master;
        routing-engine 1 backup;
        graceful-switchover {
            enable;
        }
    }

To enable the Graceful-Restart for all protocols use the following config:

routing-options {
    graceful-restart;
   }

We need to configure Grateful-Restart for all protocols which running on the
router. 


Regards,

William

-----Original Message-----
From: juniper-nsp-bounces at puck.nether.net
[mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Hemant Narkhede
Sent: Friday, June 03, 2005 2:06 PM
To: gtate at juniper.net
Cc: juniper-nsp at puck.nether.net; pekkas at netcore.fi
Subject: [j-nsp] Graceful restart & Graceful switchover

hi,

I am having M40e router with dual RE.

I am facing problem with Graceful swithover. When I do configuration as
follows:

RE1

chassis {
    redundancy {
        routing-engine 0 master;
        routing-engine 1 backup;
        sfm 0 preferred;
        failover on-loss-of-keepalives;
        graceful-switchover {
            enable;
        }

RE0

chassis {
    redundancy {
        routing-engine 0 master;
        routing-engine 1 backup;
        sfm 0 preferred;
        failover on-loss-of-keepalives;
        graceful-switchover {
            enable;

Is this a right configuration for graceful switchover? If yes, then traffic
should forward through router without interupting.

I am running OSPF,BGP & MPLS on my M40e. Is it necssary to configure
Graceful-restart for those protocol so that graceful switchover between RE's
work ?

Hemant Narkhede


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