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Visitor
Boll Lu
Posts: 6
Registered: ‎10-13-2010
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ldp-tunneling with hidden route in table inet.3

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# 
Visitor
Leo Gu
Posts: 7
Registered: ‎09-01-2011
0

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

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

 

Thanks in advance.

 

 

 

Kind regards

Leo Gu

Recognized Expert
erdems
Posts: 191
Registered: ‎12-30-2008

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

 

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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Visitor
Leo Gu
Posts: 7
Registered: ‎09-01-2011
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Re: ldp-tunneling with hidden route in table inet.3

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

Recognized Expert
erdems
Posts: 191
Registered: ‎12-30-2008
0

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

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

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If you think your question's answered, please
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Visitor
Leo Gu
Posts: 7
Registered: ‎09-01-2011
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Re: ldp-tunneling with hidden route in table inet.3

Thanks, Erdem.

 

Got it.

 

Really appreciate your help and replies.

 

 

BR

Leo Gu

 

Visitor
Leo Gu
Posts: 7
Registered: ‎09-01-2011
0

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

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

Trusted Expert
Surya
Posts: 302
Registered: ‎08-25-2009
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Re: ldp-tunneling with hidden route in table inet.3

Visitor
Leo Gu
Posts: 7
Registered: ‎09-01-2011
0

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

Hi Surya,

 

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

 

Thanks again.

 

 

 

Kind regards

Leo Gu

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