Well, yes, but that seems to be corner-case IMHO.
In nearly all cases you would include your lo0.0 into IGP, so that it is used to establish iBGP, RSVP, targeted LDP sessions. Unless special cases (like LDP tunneling when you 100% need to add lo0.0 to LDP), including lo0.0 under LDP might be over-configuration, but for sure it won't kill.
Interestingly, I've tried transport-address router-id under [edit protocols ldp] hierarchy, without adding lo0.0 to LDP, and didn't see the difference -
[edit protocols ldp]
farid@R1# run show system connections | match 646
tcp4 0 0 192.168.1.1.646 192.168.1.5.54554 ESTABLISHED
tcp4 0 0 192.168.1.1.646 192.168.1.2.63483 ESTABLISHED
After config rolled back -
[edit]
farid@R1# run show system connections | match 646
tcp4 0 0 192.168.1.1.646 192.168.1.5.58113 ESTABLISHED
tcp4 0 0 192.168.1.1.646 192.168.1.2.64152 ESTABLISHED
[edit]
farid@R1# show protocols ldp
interface ge-0/0/0.0;
interface ge-0/0/2.0;
[edit]
farid@R1# show|compare rollback 1
[edit protocols ldp]
- transport-address router-id;
Note that I haven't configured router-id explicitly under routing-options.
Here is the document about it - https://www.juniper.net/documentation/us/en/software/junos/mpls/topics/topic-map/ldp-configuration.html#id-specifying-the-transport-address-used-by-ldp
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FARID AKHUNDOV
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Original Message:
Sent: 01-11-2024 04:25
From: btodorovic
Subject: Is loopback interface lo0.0 needed under protocols mpls and rsvp/ldp stanza?
Just to update Farid's answer - if you are using transport-address router-id within the LDP configuration then you will probably need to include the interface where the router-id IP address is defined (most probably lo0.0) into LDP. So all in all, the best practice is to put it under [edit protocols ldp]. Same goes for RSVP - if the endpoints of your RSVP TE tunnel are router loopbacks, you need to insert interface lo0.0 under the [edit protocols rsvp] stanza.
In either case - no need to put lo0.0 into [edit protocols mpls] stanza at all, although it doesn't harm, but it doesn't have any effect either.
Also, no need to put family mpls in lo0.0 - same story - no harm, but no effect either.
Beri
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Berislav Todorovic
Original Message:
Sent: 01-11-2024 03:23
From: Dmitry Maksimov
Subject: Is loopback interface lo0.0 needed under protocols mpls and rsvp/ldp stanza?
Thank you, Farid. I looked at other resources and was convinced once again of what you wrote.
Best regards,
Dmitry
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Dmitry Maksimov
Original Message:
Sent: 01-11-2024 03:03
From: FARID AKHUNDOV
Subject: Is loopback interface lo0.0 needed under protocols mpls and rsvp/ldp stanza?
Well, technically, if you need to run only RSVP (or LDP), then no need to add loopback to protocols rsvp or protocols ldp hierarchy, just add it under relevant IGP.
However, if the task is to implement LDP tunneling (to tunnel LDP over RSVP LSP), then loopback should be added to protocols ldp only on MPLS routers, between which RSVP LSPs are built and used for tunneling.
------------------------------
FARID AKHUNDOV
Original Message:
Sent: 01-10-2024 10:38
From: Dmitry Maksimov
Subject: Is loopback interface lo0.0 needed under protocols mpls and rsvp/ldp stanza?
Hi guys,
I am studing deeply MPLS topic now after my course "MPLS Fundamentals" and I have a question regarding the loopback interface in MPLS matter.
In case of RSVP/MPLS should I put and include loopback interface lo0.0 under protocols mpls and protocols rsvp stanza?
For some unclear for me reason now I found that a loopback is included under protocols rsvp, but I didn't find no any rules for that in the study guide or somewhere else.
https://www.juniper.net/documentation/us/en/software/junos/mpls/topics/topic-map/mpls-p-pe-configuration.html
In case of LDP over RSVP (with ldp-tunnelling) with MPLS transport should I only point interface loopback lo0.0 under LDP?
Thank you.
Best regards,
Dmitry
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Dmitry Maksimov
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