Junos Automation (Scripting)
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Distinguished Expert
aarseniev
Posts: 1,741
Registered: ‎08-21-2009
0

Re: Just stay there!

Hello there,

Well, I guess you know the network and keeping interface down could be a solution.

But if you route statically, I'd suggest to look at using event-scripts to swap preferences/metrics of primary static and backup static routes. This way if the backup path has problems, application packets can use old-primary-new-backup route again and as you said, it is able to recover from pkt loss.

Regards

Alex

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New User
JR@RA
Posts: 2
Registered: ‎07-27-2010
0

Re: Just stay there!

Yes I have a feeling it has to do with out of order packets. We are running Oracle streams 10g and the initial convergence using BFD along with metrics works great because we get that packet loss. However, no packet loss on return back....

 

1. Original path is down but network does converge till 20sec later (Oracle Streams recovers! due to packet loss)

2. On return back to original path (no dropped packets) while BFD changes state. Oracle Streams is unaware and crashes.

 

We are trying this script on our J series to force the interface down and keep it down.

 

event-options {
    policy enable-alternate-nexthop {
        events ping_test_failed;
        within 30 {
            trigger on 14;
        }
        then {
            event-script enable-alternate-nexthop.slax {
                arguments {
                    next-hop-interface ge-0/0/3;

services {
    rpm {
        probe icmp-ping-probe {
            test ping-probe-test {
                probe-type icmp-ping;
                target address 10.192.168.2;
                test-interval 2;
            }
        }
    }
}

 

How do You route the traffic?

static mostly

 

Do you use MPLS, either LDP or RSVP?

NO MPLS

 

Do you use traffic engineering?

No

Distinguished Expert
aarseniev
Posts: 1,741
Registered: ‎08-21-2009
0

Re: Just stay there!

Hello,

There is not enough information to determine best course of action.

Does your application tolerate packet loss? Does it tolerate out-of-order packets? If yes to what extent?

How do You route the traffic? Along IGP best path? Or statically? Or along BGP best path? Do you use MPLS, either LDP or RSVP? Do you use traffic engineering?

Regards

Alex

___________________________________
Accept as Solution = cool !
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New User
JR@RA
Posts: 2
Registered: ‎07-27-2010
0

Just stay there!

Hi everyone. Has anyone experienced problems with other applications when the network is converging? Well I a right now. Does anyone know how to coverge once to an alternate path and actually stay there and no reconverge? Currently, I am exploring automated scripts (SLAX) to do this, as our current BFD implemenation is not working.

 

Thanks. 

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