Routing

Hi,

I am facing an issue which after lot of efforts didn't fix. I have a topoloy in LAB which is attached.

Configuring an LSP from R1 to R8 with link protection and controlled path,

root@OLIVE-R1# show protocols mpls

 no-cspf;

label-switched-path R1-to-R8

{    to 10.200.86.3;

    link-protection;

    primary R1-R3-R6-R8;

}

path R1-R3-R6-R8

{

    10.200.86.6 loose;

    10.200.86.1 loose;

}

interface all;

)

I have configured link-protection on all transit interfaces till egress router but when i take output of RSVP session on transit router R3 then it gave me output,

root@OLIVE-R3# run show rsvp session detail 

Transit RSVP: 1 sessions
10.200.86.3

  From: 10.200.86.5, LSPstate: Up, ActiveRoute: 1

  LSPname: R1-to-R8, LSPpath: Primary

  Suggested label received: -, Suggested label sent: -  Recovery label received: -,

Recovery label sent: 100304  Resv style: 1 SE, Label in: 100416, Label out: 100304 

Time left:  140, Since: Sun Jul 18 03:21:44 2010 

Tspec: rate 0bps size 0bps peak Infbps m 20 M 1500 

Port number: sender 1 receiver 14431 protocol 0 

Link protection desired 

Type: Protection down 

PATH rcvfrom: 192.168.86.6 (em2.0) 25 pkts 

Adspec: received MTU 1500 sent MTU 1500 

PATH sentto: 192.168.86.45 (em4.0) 22 pkts 

RESV rcvfrom: 192.168.86.45 (em4.0) 21 pkts

  Explct route: 192.168.86.45 10.200.86.1  

Record route: 192.168.86.6 <self> 192.168.86.45 192.168.86.50 192.168.86.25  Total 1 displayed, Up 1, Down 0

Pls help me out to fix this issue,

Regards,

Khurram

Hi Khurram,

    Form the attached topology diagram and the ER0 defined, R3 should have sent RESV PATH message to "em3" link, however from your output, it appears it sent over "em4" link.


Adspec: received MTU 1500 sent MTU 1500
PATH sentto: 192.168.86.45 (em4.0) 22 pkts
RESV rcvfrom: 192.168.86.45 (em4.0) 21 pkts

So I am suspecting em3 link between R3 and R6 to be down and hence the link-protection is not up on R3.
Check if the mpls/rsvp are enabled on em3 link. Would be good if you can attach R3 and R6 configs.

Regards
Surya Prakash

Hi,

There was inactivity issue between R3 and R6 over em3 which has been resolved now. Attached are the configs of R3 and R6. 

Thanks for the reply.

Khurram

Attachment(s)

R3-Config.txt   744 B 1 version

R6-Config.txt   869 B 1 version

Hi Khurram,

 Are you using OSPF as IGP? If so, can you check if you have enabled traffic-engineering knob in ospf ("set protocols ospf traffic-engineering") on all the routers? One reason you might be facing this issue is because of this. You are using no-cspf on the ingress, but R3 need to ingress the bypass to protect the link R3-R6 and it will look at TED for that.

If you still face the issue, please give "show mpls lsp extensive" o/p on R3

Thanks,

Pavan

Thanks Pavan,

you are absolutely right, configuration which i am missing is to enable traffic-engineering. My IGP is OSPF and as per you, i need to enable traffic-engineering. I have get my by pass LSPs on transit routers now.

But i am still not able to udnerstand that why there is a need to have TED for by-pass ingress LSP, although there is absolutely no need of it for normal ingress LSP(one which i am initiating from R1 for which this whole protection is for).

Regards,

Khurram

Khurrum,

Good to hear it worked 🙂

 In your case, you disabled cspf in R1. But R3 had to initiate bypass LSP and it does it through CSPF. Hence, without TED, R3 fails to bring up the bypass LSP. Since IGP gives only the best path, for any alternate path calculation (like bypass, FRR-detour) to work, you need CSPF which inturn needs TED.

Can you try enable traceoptions in mpls at R4 ("set protocols mpls traceoptions flag all" and "set protocols mps traceoptions file mpls-trace") and check the tracefile. You wil see CSPF trying to initiate bypass and failing

* Please accept the solution if it solves your query

* Kudos will be appreciated as well 🙂

Thanks,

Pavan

Yeah Pavan,

I can see logs on R3 that in the absence of TED, it is continously trying to bring by-pass LSP up but failign to do so. 

Thanks for your help.

Khurram

hi khurram,

can you help me with your email id, i need some query regarding olive if you could help me.

regards,

raju