[j-nsp] MPLS OAM not triggering LSP

Dario dario.donsion at soporte.rediris.es
Thu Apr 26 05:18:44 EDT 2007


Sail,

Just one error in my last e-mail:

On the static route at Router B

 [Router B]
 	route 10.0.0.1/32 {
 	    next-hop public_address_1;    ----> not _2!!
 	    bfd-liveness-detection {
 	        minimum-interval 1000;
 	        multiplier 1;
 	    }
 	    no-readvertise;
 	}

Have you tried this conf? It works fine for me :)

Regards,

	Dario D.

El Miércoles, 25 de Abril de 2007 13:25, Dario escribió:
> Sail,
> 
> The Tunnel is only for be informed when the triggered interface is failing or not. 
> When the interface is ok the tunnel will be up and when it fails the tunnel is down.
> 
> Is a bit tricky ;) I'll try to explain it.
> 
> Suposse you want to check the ge between router A and B:
> 
> 	RouterA --- [GE] --- SW1--SW2--SW2 --- [GE] --- RouterB
> 
> The interface you want to monitor: (Router A)
> 
> 	ge-0/0/0 {
> 		description "-- Triggered interface --";
> 		vlan-tagging;
> 		unit X {
> 			    vlan-id X;
> 			    family inet {
> 			        no-redirects;
> 			        address "public_address_1/30;   --> the end-point is public_address_2
> 			    }
> 			}
> 	}
> 
> No way to monitor when it fails due to the path in the middle.
> I've tried LSP's/BFD but... never works!
> 
> Then I configure a tunnel interface: (Router A)
> 
> 	ip-x/x/x {
> 		unit 666 {
> 		    description "-- Tunel CANT-CANL --";
> 			    tunnel {
> 			        source 10.0.0.1;         ---> these addreses are not used in your network
> 			        destination 10.0.0.2;
> 			    }
> 		}
> 	}
> 
> The tunnel goes up when you define an static route via the triggered interface:
> 
> (Router A)
> 	route 10.0.0.2/32 {
> 	    next-hop public_address_2;
> 	    no-readvertise;
> 	}
> 
> No traffic will go via this tunnel, is only UP or (as you can see  when BFD is configured :) ) DOWN.
> 
> To force the tunnel to be down I use BFD.
> 
> [Router A]
> 	route 10.0.0.2/32 {
> 	    next-hop public_address_2;
> 	    bfd-liveness-detection {
> 	        minimum-interval 1000; ---> hello packets every second
> 	        multiplier 1;
> 	    }
> 	    no-readvertise;
> 	}
> 
> [Router B]
> 	route 10.0.0.1/32 {
> 	    next-hop public_address_2;
> 	    bfd-liveness-detection {
> 	        minimum-interval 1000;
> 	        multiplier 1;
> 	    }
> 	    no-readvertise;
> 	}
> 
> (this static route in router B is only to establish the BFD session)
> 
> When the GE fails (but it's UP), the BFD goes DOWN, the static route dissapear and the Tunnel IP goes 
> DOWN too, then you receive an SNMP_TRAP_LINK_DOWN from this Tunnel and you can be sure the GE
> is failing.
> 
> The Tunnel is only to be noticed of the GE fails, no used for traffic. No way to force the GE to goes DOWN,
> but you can monitor it in this indirect way.
> 
> Hope it helps.
> 
> Regards,
> 
> 	Dario D.
> 
> 
> El Miércoles, 25 de Abril de 2007 12:38, Sailendra Mahanty escribió:
> > Hi Dario,
> > 
> > Removing the j-nsp list.
> > 
> > Good to know that you have explored these options however the lt interface (of tunnel pic) may be a bottle neck for the traffic if you are making your traffic pass thru this interface. I am sure you are aware of this.
> > 
> > BTW, is it possible to share your config with me to check if there are any other potential problems.
> > 
> > Thanks,
> > -sail
> > 
> > 
> > -----Original Message-----
> > From: Dario [mailto:dario.donsion at soporte.rediris.es] 
> > Sent: Wednesday, April 25, 2007 3:28 AM
> > To: juniper-nsp at puck.nether.net
> > Cc: Sailendra Mahanty; Sinan Ilkiz
> > Subject: Re: [j-nsp] MPLS OAM not triggering LSP
> > 
> > Dear all,
> > 
> > I've tried BFD with LSPs but I wasn't able to make it work.
> > 
> > If you've the possibility to use a Tunnel PIC - with a ficticious interface (f.e. with private address) 
> > and static routes (via the end-point of the interface you want to trigger) with BFD - is a good option, 
> > it works for me: in the instant the triggered interface fails, BFD goes down and the tunnel too.
> > 
> > If you finally can use LSP's pleas keep us informed :)
> > 
> > Regards,
> > 
> > 	Dario D.
> > 
> > El Miércoles, 25 de Abril de 2007 12:13, Sailendra Mahanty escribió:
> > > Hi Sinan,
> > > 
> > > Current version of JunOS that you are using, logs an error message when LSP goes down because of BFD as mentioned in page-191 of the following doc. However it doesn't make the LSP down.
> > > 
> > > http://www.juniper.net/techpubs/software/junos/junos81/swconfig81-mpls-apps/download/swconfig81-mpls-apps.pdf
> > > 
> > > thanks,
> > > -sail
> > > 
> > > -----Original Message-----
> > > From: juniper-nsp-bounces at puck.nether.net [mailto:juniper-nsp-bounces at puck.nether.net] On Behalf Of Sinan Ilkiz
> > > Sent: Wednesday, April 25, 2007 1:55 AM
> > > To: juniper-nsp at puck.nether.net
> > > Subject: [j-nsp] MPLS OAM not triggering LSP
> > > 
> > > Hi all,
> > >  
> > > We are trying to achieve fast convergence times for one of our links. We can not detect link failures in this link directly, i.e. interface never goes down in case of failures. We decided that we can benefit from BFD for LSPs. We are testing this configuration;
> > >  
> > > label-switched-path lsp_to_bt_j_2_sifir {
> > >     from 192.168.100.1;
> > >     to 192.168.100.2;
> > >     ldp-tunneling;
> > >     no-cspf;
> > >     link-protection;
> > >     primary via_sifir {
> > >         oam {
> > >             bfd-liveness-detection {
> > >                 minimum-interval 300;
> > >                 multiplier 3;
> > >             }
> > >         }
> > >     }
> > > }
> > >  
> > >  
> > > When we simulate an indirect failure, we see that BFD session goes down but LSP's path does not change. So this causes extended downtimes as long as RSVP states time out. We couldn't find out what we are doing wrong. In my opinion, when BFD detects the failure, it should signal to the local router and say "this path is no longer available, you should find another way". We tested both secondary standby and link-protection options but nothing changed. We used both 7.6R4 and 8.1R3. Test lab consists of one m7i and J4300 connected via their ethernet links.
> > >  
> > > M7i === switch1 === switch2 === J4300
> > >  
> > > One ethernet link is used as LSP path and other is used as backup link. Switch configuration is done in such a way that (using VLANs) fe-1/3/0 of M7i and fe-0/0/0 of J4300 form the first path; fe-1/3/1 of M7i and fe-0/0/1 of J4300 form second path. To simulate a failure we plug off the fist cable between switch1 and switch2 so neither M7i nor J4300 knows this problem directly and only the first path (between fe-1/3/0 and fe-0/0/0) is affected. This way, we tried to simulate an indirect failure.
> > >  
> > > lab at BT-M-1> show mpls lsp ingress extensive    
> > > Ingress LSP: 1 sessions
> > >  
> > > 192.168.100.2
> > >   From: 192.168.100.1, State: Up, ActiveRoute: 0, LSPname: lsp_to_bt_j_2_sifir
> > >   ActivePath: via_sifir (primary)
> > >   Link protection desired
> > >   LoadBalance: Random
> > >   Encoding type: Packet, Switching type: Packet, GPID: IPv4
> > >  *Primary   via_sifir        State: Up
> > >     SmartOptimizeTimer: 180
> > >     Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
> > >           10.1.1.2(Label=3)
> > >     OAM state : BFD session up   LSP-ping up
> > >     5 Apr 25 08:34:23.102 Link-protection Up
> > >     4 Apr 25 08:33:29.085 Selected as active path
> > >     3 Apr 25 08:33:29.084 Record Route:  10.1.1.2(Label=3)
> > >     2 Apr 25 08:33:29.084 Up
> > >     1 Apr 25 08:33:29.073 Originate Call
> > >   Created: Wed Apr 25 08:33:28 2007
> > > Total 1 displayed, Up 1, Down 0
> > >  
> > > Then we plug off the appropriate cable at "2007-04-25 08:37:55 UTC"
> > >  
> > > lab at BT-M-1> show mpls lsp ingress extensive    
> > > Ingress LSP: 1 sessions
> > >  
> > > 192.168.100.2
> > >   From: 192.168.100.1, State: Up, ActiveRoute: 0, LSPname: lsp_to_bt_j_2_sifir
> > >   ActivePath: via_sifir (primary)
> > >   Link protection desired
> > >   LoadBalance: Random
> > >   Encoding type: Packet, Switching type: Packet, GPID: IPv4
> > >  *Primary   via_sifir        State: Up
> > >     SmartOptimizeTimer: 180
> > >     Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
> > >           10.1.1.2(Label=3)
> > >     OAM state : BFD session not up   LSP-ping up
> > >     7 Apr 25 08:38:01.917 Link-protection Up
> > >     6 Apr 25 08:38:01.914 Link-protection Down
> > >     5 Apr 25 08:34:23.102 Link-protection Up
> > >     4 Apr 25 08:33:29.085 Selected as active path
> > >     3 Apr 25 08:33:29.084 Record Route:  10.1.1.2(Label=3)
> > >     2 Apr 25 08:33:29.084 Up
> > >     1 Apr 25 08:33:29.073 Originate Call
> > >   Created: Wed Apr 25 08:33:28 2007
> > > Total 1 displayed, Up 1, Down 0
> > >  
> > > LSP is still traversing the down link. After a short while,
> > >  
> > > lab at BT-M-1> show mpls lsp ingress extensive            
> > > Ingress LSP: 1 sessions
> > >  
> > > 192.168.100.2
> > >   From: 192.168.100.1, State: Up, ActiveRoute: 0, LSPname: lsp_to_bt_j_2_sifir
> > >   ActivePath: via_sifir (primary)
> > >   Link protection desired
> > >   LoadBalance: Random
> > >   Encoding type: Packet, Switching type: Packet, GPID: IPv4
> > >  *Primary   via_sifir        State: Up
> > >     SmartOptimizeTimer: 180
> > >     Received RRO (ProtectionFlag 1=Available 2=InUse 4=B/W 8=Node 10=SoftPreempt):
> > >           10.1.1.6
> > >     OAM state : BFD session not up   LSP-ping up
> > >    11 Apr 25 08:38:38.265 Record Route:  10.1.1.6
> > >    10 Apr 25 08:38:38.264 Record Route:  10.1.1.6
> > >     9 Apr 25 08:38:35.237 Tunnel local repaired
> > >     8 Apr 25 08:38:35.237 Down
> > >     7 Apr 25 08:38:01.917 Link-protection Up
> > >     6 Apr 25 08:38:01.914 Link-protection Down
> > >     5 Apr 25 08:34:23.102 Link-protection Up
> > >     4 Apr 25 08:33:29.085 Selected as active path
> > >     3 Apr 25 08:33:29.084 Record Route:  10.1.1.2(Label=3)
> > >     2 Apr 25 08:33:29.084 Up
> > >     1 Apr 25 08:33:29.073 Originate Call
> > >   Created: Wed Apr 25 08:33:28 2007
> > > Total 1 displayed, Up 1, Down 0
> > >  
> > > So it takes for LSP to switch to backup path from 08:37:55 to 08:38:38. I couldn't find a logical explanation why BFD does not trigger LSP.
> > >  
> > > Anyone of you tried to use MPLS OAM and hit the same problem?
> > >  
> > > Regards.
> > > _______________________________________________
> > > 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
> > > 
> > > 
> > 
> > 
> 



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