Routing

Hi Junipers,

I have topology like this:

PE1 -- CORE -- PE2.

I make LSPs between PE1 and CORE (two ways), and make LSPs between CORE and PE2 (two ways).

From PE1 only get CORE lo0 address in inet.3:

root# run show route table inet.3 logical-system PE1 

inet.3: 2 destinations, 4 routes (1 active, 0 holddown, 2 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.2/32         *[RSVP/7/1] 00:27:26, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE
                    [LDP/9] 00:27:26, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE

root# run show route table inet.3 logical-system CORE 

inet.3: 3 destinations, 7 routes (2 active, 0 holddown, 3 hidden)
+ = Active Route, - = Last Active, * = Both

1.1.1.1/32         *[RSVP/7/1] 00:27:52, metric 1
                    > to 11.11.11.1 via em1.2, label-switched-path To-PE1
                    [LDP/9] 00:27:52, metric 1
                    > to 11.11.11.1 via em1.2, label-switched-path To-PE1
3.3.3.3/32         *[RSVP/7/1] 00:27:54, metric 1
                    > to 12.12.12.2 via em2.2, label-switched-path To-PE2
                    [LDP/9] 00:27:53, metric 1
                    > to 12.12.12.2 via em2.2, label-switched-path To-PE2

root# run show route table inet.3 logical-system PE2   

inet.3: 2 destinations, 4 routes (1 active, 0 holddown, 2 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.2/32         *[RSVP/7/1] 00:28:21, metric 1
                    > to 12.12.12.1 via em3.1, label-switched-path To-CORE
                    [LDP/9] 00:28:20, metric 1
                    > to 12.12.12.1 via em3.1, label-switched-path To-CORE

I supposed to get PE2 lo0 address in PE1 inet.3 with only make LSP with ldp-tunneling from PE1 to CORE and CORE to PE2 (bidirectional).

I attach the complete config and using Qemu as the lab.

Thanks for your response.

Attachment(s)

ldp-tunneling.txt   4 KB 1 version

Doing LDP tunneling is one option and you can also create an RSVP LSP between PEs.

Both of them will install PE loopback in inet.3.

Hi,

Can you please provide the o/p of these commands?

show ldp database

show route table inet.3 hidden

Regards

Surya Prakash

Hi all,

I already put ldp tunneling in the LSP configuration but it doesnt works. I already know that if I make LSP from PE1 to PE2 they will install each lo0 address in inet.3. In this scenarion, I just want to prove that with make LSP only to COre, each PE will install lo0 address in inet.3. So. we dont need to make full mesh LSP.

These are the command that Surya requested:

root# run show ldp database logical-system all | no-more
 
logical-system: PE1
Input label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
 299776     1.1.1.1/32
      3     2.2.2.2/32
 299792     3.3.3.3/32

Output label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
      3     1.1.1.1/32
 299776     2.2.2.2/32
-----
 
logical-system: CE2
LDP instance is not running
-----
 
logical-system: CE1
LDP instance is not running
-----
 
logical-system: PE2

Input label database, 3.3.3.3:0--2.2.2.2:0
  Label     Prefix
 299776     1.1.1.1/32
      3     2.2.2.2/32
 299792     3.3.3.3/32

Output label database, 3.3.3.3:0--2.2.2.2:0
  Label     Prefix
 299776     2.2.2.2/32
      3     3.3.3.3/32
-----
 
logical-system: CORE

Input label database, 2.2.2.2:0--1.1.1.1:0
  Label     Prefix
      3     1.1.1.1/32
 299776     2.2.2.2/32

Output label database, 2.2.2.2:0--1.1.1.1:0
  Label     Prefix
 299776     1.1.1.1/32
      3     2.2.2.2/32
 299792     3.3.3.3/32

Input label database, 2.2.2.2:0--3.3.3.3:0
  Label     Prefix
 299776     2.2.2.2/32
      3     3.3.3.3/32

Output label database, 2.2.2.2:0--3.3.3.3:0
  Label     Prefix
 299776     1.1.1.1/32
      3     2.2.2.2/32
 299792     3.3.3.3/32
-----
 
logical-system: default
LDP instance is not running

root# run show route table inet.3 hidden logical-system all | no-more
 
logical-system: PE1

inet.3: 2 destinations, 4 routes (1 active, 0 holddown, 2 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.2/32          [OSPF] 00:04:00, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE
12.12.12.0/30       [OSPF] 00:04:00, metric 2
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE
-----
 
logical-system: CE2
-----
 
logical-system: CE1
-----
 
logical-system: PE2

inet.3: 2 destinations, 4 routes (1 active, 0 holddown, 2 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.2/32          [OSPF] 00:04:02, metric 1
                    > to 12.12.12.1 via em3.1, label-switched-path To-CORE
11.11.11.0/30       [OSPF] 00:04:02, metric 2
                    > to 12.12.12.1 via em3.1, label-switched-path To-CORE
-----
 
logical-system: CORE

inet.3: 3 destinations, 7 routes (2 active, 0 holddown, 3 hidden)
+ = Active Route, - = Last Active, * = Both

1.1.1.1/32          [OSPF] 00:04:01, metric 1
                    > to 11.11.11.1 via em1.2, label-switched-path To-PE1
3.3.3.3/32          [OSPF] 00:04:01, metric 1
                    > to 12.12.12.2 via em2.2, label-switched-path To-PE2
10.10.10.0/30       [OSPF] 00:04:01, metric 2
                    > to 12.12.12.2 via em2.2, label-switched-path To-PE2
                      to 11.11.11.1 via em1.2, label-switched-path To-PE1
-----
 
logical-system: default

Hi,

There is an issue seen with below output. Ideally you should see same FEC entries in Input and Ouput database.

root# run show ldp database logical-system all | no-more
 
logical-system: PE1
Input label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
 299776     1.1.1.1/32
      3     2.2.2.2/32
 299792     3.3.3.3/32

Output label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
      3     1.1.1.1/32
 299776     2.2.2.2/32
-----

However it isn't the case here with PE1 ( Same with PE2 as well). You have 3.3.3.3 in Input but not in Output.

Reason : You have an direct interface between PE1 and PE2 as well. The IGP path to reach 3.3.3.3 is em1.1 (which is direct interface to PE2) while LDP path to FEC 3.3.3.3 is em2.1

Due to this discrepancy you don't see the LDP FEC in inet.3 table.

Once you disable em1.1 interface on PE1, you should see 3.3.3.3 in inet.3 table.

Regards

Surya Prakash

Hi Surya,

Thanks for your response. It works now after I disable interface direct connected between PE1 <> PE2.

root# run show route table inet.3 logical-system PE1

inet.3: 3 destinations, 6 routes (2 active, 0 holddown, 3 hidden)
+ = Active Route, - = Last Active, * = Both

2.2.2.2/32         *[RSVP/7/1] 00:00:38, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE
                    [LDP/9] 00:00:38, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE
3.3.3.3/32         *[LDP/9] 00:00:38, metric 1
                    > to 11.11.11.2 via em2.1, label-switched-path To-CORE

[edit logical-systems]
root# run show ldp database lg 
                            ^
syntax error, expecting <command>.
root# run show ldp database logical-system PE1
Input label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
 299824     1.1.1.1/32
      3     2.2.2.2/32
 299808     3.3.3.3/32

Output label database, 1.1.1.1:0--2.2.2.2:0
  Label     Prefix
      3     1.1.1.1/32
 299824     2.2.2.2/32
 299840     3.3.3.3/32

I want to ask more, what FEC that a PE router should give a label? Or in another word, does a PE Router take FEC Prefix from every /32 prefix in table inet.0?

Thanks in advance 🙂

Hi,

By default, JUNOS advertises its /32 loopback address as FEC with a implicit null. In order to advertise other /32 routes that are in inet.0 table, you need to define "egress-policy".

Regards

Surya Prakash