Routes behind a tunnel-te unlabelled

[milton oliveira vieira]

I have created a tunnel-te from xrv16 to csr3, the tunnel is up and getting Pop label to csr3 that's ok.
From xrv16 I have learned the route to xrv17 over the tunnel, but checking the Label it's unlabbled as well.
I believe the route from xrv16 to xrv17 would be labeled normally over the tunnel-te or am I wrong?

Base topology.
[xrv16]-----[csr10]-----[csr3]-------[xrv17]

----------------------------Route to CSR3, over the tunnel Ok.--------------------------
RP/0/0/CPU0:xrv16#show route 10.10.10.3
Mon May 13 19:32:40.832 UTC

Routing entry for 10.10.10.3/32
Known via "isis 1", distance 115, metric 20, type level-2
Installed May 13 19:21:37.618 for 00:11:03
Routing Descriptor Blocks
10.10.10.3, from 10.10.10.3, via tunnel-te10
Route metric is 20
No advertising protos.
RP/0/0/CPU0:xrv16#

----------------------------Route to CSR3, over the tunnel Ok.--------------------------

------------------------Pop Label over the tunel Ok----------------------------------

RP/0/0/CPU0:xrv16#show mpls forwarding prefix 10.10.10.3/32
Mon May 13 19:32:47.242 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
------ ----------- ------------------ ------------ --------------- ------------
24003 Pop 10.10.10.3/32 tt10 10.10.10.3 0
RP/0/0/CPU0:xrv16#

------------------------Pop Label over the tunel Ok----------------------------------

----------------------------Route to xrv17, over the tunnel Ok.--------------------------

RP/0/0/CPU0:xrv16#show route 10.10.10.17
Mon May 13 22:13:24.282 UTC

Routing entry for 10.10.10.17/32
Known via "isis 1", distance 115, metric 20, type level-2
Installed May 13 19:39:10.875 for 02:34:13
Routing Descriptor Blocks
10.10.10.3, from 10.10.10.17, via tunnel-te10
Route metric is 20
No advertising protos.
RP/0/0/CPU0:xrv16#

----------------------------Route to xrv17, over the tunnel Ok.--------------------------

------------------------No Label for the prefix----------------------------------

RP/0/0/CPU0:xrv16#show mpls forwarding prefix 10.10.10.17/32
Mon May 13 22:13:29.761 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
------ ----------- ------------------ ------------ --------------- ------------
24006 Unlabelled 10.10.10.17/32 tt10 10.10.10.3 0
RP/0/0/CPU0:xrv16#

------------------------No Label for the prefix----------------------------------

RP/0/0/CPU0:xrv16#show running-config interface tunnel-te 10
Mon May 13 22:16:16.680 UTC
interface tunnel-te10
description TO-->CSR10-->CSR3
bandwidth 100
ipv4 unnumbered Loopback0
destination 10.10.10.3
fast-reroute
forwarding-adjacency
!
path-option 10 dynamic
!

RP/0/0/CPU0:xrv16#

[MHM Cisco World]

It unlabeled for outgoing and that OK.

For local label as I see there is label and it send to other tunnel end.

In simple word 

There are two label' one upper for tunnel scr/dest and other lower for prefix' upper need local and outgoing and lower need only local label

MHM

[Harold Ritter · Accepted solution]

Hi @milton oliveira vieira ,

The traffic to xrv17 loopback address will definitely be label switched as the next hop interface for this prefix is the tunnel interface. But it will not be label switched end to end. 

If you want it to be label switched end to end, you could enable ldp on the tunnel interface. You will also need to enable ldp on csr3 (as targeted ldp or on the tunnel interface if you have a tunnel to xrv16).

Regards,

[milton oliveira vieira]

Hi Harold Ritter, thank you for your time.

After adding the following configuration from now on I've label end-to-end.

xrv16
mpls ldp interface tunnel-te10 address-family ipv4
mpls ldp neighbor 10.10.10.3:0 password disable

CSR3
mpls ldp neighbor 10.10.10.16 targeted ldp
#
RP/0/0/CPU0:xrv16#show mpls forwarding prefix 10.10.10.17/32
Tue May 14 16:32:45.143 UTC
Local Outgoing Prefix Outgoing Next Hop Bytes
Label Label or ID Interface Switched
------ ----------- ------------------ ------------ --------------- ------------
24006 17 10.10.10.17/32 tt10 10.10.10.3 0
RP/0/0/CPU0:xrv16#

[MHM Cisco World]

can you try ping from end to end 
MHM

[Harold Ritter]

Hi @MHM Cisco World ,

Regular ping will not help proving end to end label switching. The "ping mpls" tool would be a better approach. ping mpls requires "mpls oam" to be configured on all devices in the path.  

Regards,

[milton oliveira vieira]

Yes, ping mpls is working fine.

RP/0/0/CPU0:xrv16#ping mpls ipv4 10.10.10.17/32 source 10.10.10.16
Tue May 14 17:57:02.027 UTC

Sending 5, 100-byte MPLS Echos to 10.10.10.17/32,
timeout is 2 seconds, send interval is 0 msec:

Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
'L' - labeled output interface, 'B' - unlabeled output interface,
'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
'M' - malformed request, 'm' - unsupported tlvs, 'N' - no rx label,
'P' - no rx intf label prot, 'p' - premature termination of LSP,
'R' - transit router, 'I' - unknown upstream index,
'X' - unknown return code, 'x' - return code 0

Type escape sequence to abort.

!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/4/10 ms
RP/0/0/CPU0:xrv16#

RP/0/0/CPU0:xrv16#traceroute mpls ipv4 10.10.10.17/32 source 10.10.10.16
Tue May 14 17:58:13.352 UTC

Tracing MPLS Label Switched Path to 10.10.10.17/32, timeout is 2 seconds

Codes: '!' - success, 'Q' - request not sent, '.' - timeout,
'L' - labeled output interface, 'B' - unlabeled output interface,
'D' - DS Map mismatch, 'F' - no FEC mapping, 'f' - FEC mismatch,
'M' - malformed request, 'm' - unsupported tlvs, 'N' - no rx label,
'P' - no rx intf label prot, 'p' - premature termination of LSP,
'R' - transit router, 'I' - unknown upstream index,
'X' - unknown return code, 'x' - return code 0

Type escape sequence to abort.

0 192.168.1.16 MRU 1546 [Labels: 22/17 Exp: 0/0]
L 1 192.168.1.10 MRU 1560 [Labels: implicit-null/17 Exp: 0/0] 0 ms
L 2 192.168.2.3 MRU 1560 [Labels: implicit-null Exp: 0] 0 ms
! 3 192.168.3.17 1 ms
RP/0/0/CPU0:xrv16#

[MHM Cisco World]

Nice Conversation here 
As I know and I run lab for that 
there is TE between R1 and R3 and I dont run MPLS IP under the TE and the ping is success and work 
the idea is you build tunnel between R1 and R3 and R2 dont know what behind this tunnel so it mandatory to have two label 
as I mention the local is assign to prefix learn via TE (i.e. behind TE) and outgoing label not need since the tunnel will use the label of tunnel source and destination to forward traffic,

when we run mpls IP in TE you need to make all router along the path to know this label and this need to make all router along the path know the routes behind the TE

we can use TE in MPLS and run MPLS over it but that another story 

MHM

thanks for all 
MHM

[milton oliveira vieira]

Dear MHM I really agree with you, but the issue was the routes behind the tunnel. So, if you add another Router after the R3 you will see same problem, it means if you add one more Router R30 with the loopback 30.30.30.30/32 probably it will come on the R1 Unlabelled.

Thank you for your time.

[MHM Cisco World]

I will try add one more router and update you.

Thanks 

MHM

[MHM Cisco World]

Hi friend 
I make it more hard 
I re build lab have two path between R1 and R3 (MPLS TE heads)
and you can see I traceroute from R4 to R5 which also run MPLS LDP and you see
first one when the MPLS TE path DOWN ( f2/1 shut )
second when the MPLS TE path UP
also I share the R2 mpls forwarding table 
all of these without make MPLS TE run target LDP, 
the idea when traffic come to R1 from R4, the traffic can use Label of Tunnel if tunnel is UP or it can use label via R2

thanks 
MHM

[MHM Cisco World]

one more point 
usually we use MPLS TE between PE not between P in MPLS SP Core

there is some case, but as I mention that another story

MHM

[Harold Ritter]

Hi @MHM Cisco World ,

I have personally seen many service providers running MPLS TE between P routers only rather than between PEs for scalability purposes.

They then use LDP over the TE tunnels to create end to end LSP.

Regards,

[MHM Cisco World]

Maybe I missing something here' but I will do more search about ldp over mpls te.

I will share any update here 

Thanks alot 

MHM

[Harold Ritter]

Hi @MHM Cisco World ,

> There are two label' one upper for tunnel scr/dest and other lower for prefix'

There is only one label here. The transport label signalled via RSVP. There would be two labels if he ran LDP over the tunnel interface. This would provide end to end label switching.

Regards,