Unified-MPLS

[feroz syed]

Below topology having issue with end to end connectivity, Topology details follows

R1(CE) and R2 (PE) both connected via vrf vpnv4 bgp.

R2 (PE) R3 (PE) both connected to R4 (PC) using iBGP

R4(PC) & R5 (PC) also both using iBGP

R6 (PE)Connected to R7 (CE) device using vrf vpnv4 bgp.

R4 & R5 redistribute its loopback address to OSPF-1 Area0 (4.4.4.4 & 5.5.5.5)

Now the issue is R2  and R6 both can ping loopback address, but not able to ping opposite customer site.

Both Customer R1 and R7 have customer route but the trace not pass after R6 and R2.

[Harold Ritter]

This is the purpose of the

ping mpls and traceroute mpls

command.

Regards,

[feroz syed]

but as you see those cmd only shows BBB B' - unlabeled output, from this output we can only decide somewhere label is missing but not able to see exactly which device having label issue.

[Harold Ritter]

This was a strong indication that a label was not received from R5 because the label advertisement had not been negotiated with R5.

Regards,

[feroz syed]

thanks again for pointing out the issue, i will close this discussion, soon see you one different discussion.

Thanks

[Harold Ritter]

It is always a pleasure to assist.

Regards,

[MHM Cisco World]

I take fast look, this is Intra-AS MPLS not unified-MPLS, 
I now reading this subject and there are 8 hours video explain the concept, 
I will update you how you run unified-MPLS with same topology. 

[Harold Ritter]

Hi @MHM Cisco World ,

The fact that he is using iBGP does not prevent it to be a unified MPLS scenario. He is running multiple IGP/LDP domains and he sets up BGP-LU on top of them. This is the idea behind unified MPLS.

Regards,

[MHM Cisco World]

MPLS Core 
we have ONE AS for ALL MPLS Core so I will talk about Intra-AS 
when there is two SP and two different AS then this is Inter-AS not Intra-AS 

so Now we have one big AS, this AS run three or more IGP inside the MPLS Core, 
in my explain I will use OSPF-100-OSPF-200-OSPF-110
so we have two solution here 
1-w/o unified-MPLS 
A- make each IGP advertise the LO of PE 
B- make ASBR redistribute these LO between IGP 
this make each PE and each ASBR have all LO of all PE in MPLS Core 
this make each router build LDP label forwarding table for all LO of all PE in MLPS Core 

so PE1 in OSPF 100 to VPNv4 to PE2 in OSPF 110 (the Core OSPF is 200) the PE1 will send label for LO of PE2 
that nightmare for admin close your eyes in figure how many LSR you must check.

solution 
2-unified-MPLS 
A- make each IGP advertise the LO of PE 
B-make ASBR redistribute it LO only between IGP 
ONLY ? what you mean and how it work ??

how it work? answer is  we will use multi iBGP (iBGP because intra-AS use same AS so we need iBGP)
this iBGP make each PE know the LO of other PE in other IGP via ASBR LO, 
but again what that mean ?
this meaning PE in one IGP use only one label to reach all PE in other IGP, this label is ASBR LO label. 

this reduce the LABEL and routing table for Each PE and ASBR. 

and for your Q how we use detect label as @Harold Ritter  suggest ping mpls is best way. 

[feroz syed]

Can you please elaborate little more about below points... "one label to reach all PE"

PE in other IGP via ASBR LO, 
but again what that mean ?
this meaning PE in one IGP use only one label to reach all PE in other IGP, this label is ASBR LO label. 

this reduce the LABEL and routing table for Each PE and ASBR. 

[MHM Cisco World]

Sure I will share the MPLS Label for both case w and w/o unified-MPLS. 

[MHM Cisco World]

w/o unified-mpls 
see all LO in R2 (PE) with is label in forwarding-table even if some LOOP and prefix is not in IGP of R2.

with unified-mpls, only the LO for R3 (ASBR) is list in R2 
note:- 75.0.0.0/32 is for second PE I add to IGP OSPF 100

this way what is important to R2 is only the label of ASBR. 
great.