Routing
Routing

ldp-tunneling with hidden route in table inet.3

09.17.11   |  
‎09-17-2011 09:38 PM
r1--rsvp--r2 r1-r2,enable ldp tunnel ,create extensive ldp neighbor, after enable ldp tunnel ,why generate hidden route in tabel inet.3 juniper@LAB# show protocols mpls label-switched-path r1-te to 10.20.11.1; ldp-tunneling; [edit logical-systems r1] juniper@LAB# run show route table inet.3 logical-system r1 inet.3: 1 destinations, 3 routes (1 active, 0 holddown, 1 hidden) + = Active Route, - = Last Active, * = Both 10.20.11.1/32 *[RSVP/7/1] 00:23:12, metric 10 > to 10.10.10.1 via ge-0/1/1.456, label-switched-path r1-te [LDP/9] 00:11:38, metric 1 > to 10.10.10.1 via ge-0/1/1.456, label-switched-path r1-te [edit logical-systems r1] juniper@LAB# run show route table inet.3 logical-system r1 hidden inet.3: 1 destinations, 3 routes (1 active, 0 holddown, 1 hidden) + = Active Route, - = Last Active, * = Both 10.20.11.1/32 [IS-IS] 00:11:46, metric 10 > to 10.10.10.1 via ge-0/1/1.456, label-switched-path r1-te [edit logical-systems r1] juniper@LAB#
8 REPLIES
Routing

Re: ldp-tunneling with hidden route in table inet.3

12.11.11   |  
‎12-11-2011 03:17 AM

Yes, im experiencing the same issue. Could any expert bring us any light on this question?

 

Thanks in advance.

 

 

 

Kind regards

Leo Gu

Routing

Re: ldp-tunneling with hidden route in table inet.3

12.13.11   |  
‎12-13-2011 02:54 PM

 

Hi all,

 

 This is a result of how ldp-tunneling is operating and is expected. Effectively, when ldp-tunneling is configured for a given RSVP LSP, JUNOS enables igp-shortcuts in the background. This is later on used to determine which RSVP LSPs can/will be used to tunnel for the LDP FEC. (seek answer to "What LDP FEC is behind each RSVP LSP?")

 

 However, since the configuration does not have igp-shortcuts knob enabled explicitly, JUNOS needs to make sure that they won't be used for other protocols (e.g. resolving a bgp next-hop), so they're shown as hidden in the CLI.

 

 Hope this clarifies it.

 

 Erdem

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Routing

Re: ldp-tunneling with hidden route in table inet.3

12.15.11   |  
‎12-15-2011 08:06 AM

Hi Erdems,

 

Many thanks for your answer which greatly helped me out of this issue.

 

May I ask a little more regarding the result of this kind of config?

If I just let those hidden routes resulted from "ldp-tunneling" to be there in inet.3, I mean if I do not config the "igp-shortcuts" explicitly under the [edit protocols ospf traffic-engineering shortcuts] hierarchy level, are there any negtive effects to the live network?

 

 

Thanks.

 

 

Kind regards

Leo Gu

Routing

Re: ldp-tunneling with hidden route in table inet.3

12.15.11   |  
‎12-15-2011 12:42 PM

Hey Leo,

 

 I'm happy to hear that.

 

 I may have not been entirely clear on my previous message. You do NOT need to use igp-shortcuts together with ldp-tunneling.

 

 The hidden routes you're seeing are harmless, think of them as a by-product due to the way ldp-tunneling works internally within JUNOS.

 

 Thanks,

 Erdem

____________________________________________
If you think your question's answered, please
mark the respective post as "Accepted Solution".

Kudos are an excellent way of showing appreciation, too.
Routing

Re: ldp-tunneling with hidden route in table inet.3

12.16.11   |  
‎12-16-2011 03:47 AM

Thanks, Erdem.

 

Got it.

 

Really appreciate your help and replies.

 

 

BR

Leo Gu

 

Routing

Re: ldp-tunneling with hidden route in table inet.3

12.16.11   |  
‎12-16-2011 01:55 PM

Hi Erdem,

 

Sorry but I have to re-open this thread as I am a bit confused with the "igp-shortcuts" you mentioned below.

=======================
This is a result of how ldp-tunneling is operating and is expected. Effectively, when ldp-tunneling is configured for a given RSVP LSP, JUNOS enables igp-shortcuts in the background. This is later on used to determine which RSVP LSPs can/will be used to tunnel for the LDP FEC. (seek answer to "What LDP FEC is behind each RSVP LSP?")
=======================

 

So could you pls kindly let me know which config is the correct one you meant when you mention the "igp-shortcuts"?
option 1)      set protocols mpls traffic-engineering bgp-igp
option 2)      set protocols isis/ospf traffic-engineering shortcuts

 

Thanks in advance.

 

 

BR

Leo Gu

Routing

Re: ldp-tunneling with hidden route in table inet.3

12.16.11   |  
‎12-16-2011 02:25 PM
Routing

Re: ldp-tunneling with hidden route in table inet.3

12.17.11   |  
‎12-17-2011 04:08 AM

Hi Surya,

 

Thanks for your link very much which really clears my confusion.

 

Thanks again.

 

 

 

Kind regards

Leo Gu