The document discusses MPLS LDP configurations for establishing xconnect circuits to connect customer edge routers CE-R7 and CE-R8 to provider edge routers R1 and R6 respectively. Interface configurations on R1 and R6 set up xconnects with encapsulation MPLS and VC IDs. Show commands confirm the local and remote VC labels exchanged via LDP signaling and the end-to-end MPLS label stacks imposed.

1. 1. MPLS – LDP - Xconnects
Loops:
R1 192.168.0.1
R2 192.168.0.2
… etc
We should be familiar with:-
. IGP & Routing Generally
. MPLS LDP Distribution
. MPLS Labels and how to follow
. Understanding of Labels LSR
. Behavior LSR-to-LSR
R5
R1 R2
R3 R4
R6
Fa0/1
1.6/30
Fa0/0
1.1/30
Fa0/0
1.2/30 Fa0/1
1.5/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
Fa1/0
1.17/30
F0/0
1.18/30
F0/1
1.21/30
F0/1
1.22/30

2. 2. MPLS – LDP - Xconnects
Adding CE Portion to the Network
Interconnects:
CE-R7 <==> R1
Fa0/1 Fa1/0
CE-R8 <==> R6
Fa0/0 Fa0/0
We/ISP will try and provide CE with a
point-to-point connection (l2circuit)
and we use MPLS for this.
After this is done, CE can configure
their own IP between CE.R7 – CE.R8
R5
R1 R2
R3 R4
R6
Fa0/1
1.6/30
Fa0/0
1.1/30
Fa0/0
1.2/30 Fa0/1
1.5/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
Fa1/0
1.17/30
F0/0
1.18/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
P-to-P

3. 3. MPLS – LDP - Xconnects
Configs on R1
R1#show run interface fa 1/0
!
interface FastEthernet1/0
description r1-ce7
no ip address
xconnect 192.168.0.6 99 encapsulation mpls
End
NOTE: Nothing special on CE.R7 & CE.R8 – xconnects
are totally transparent to customers
Configs on R6
R6#show run interface fa0/0
!
interface FastEthernet0/0
description r6-ce8
no ip address
xconnect 192.168.0.1 99 encapsulation mpls
end
VCID 99
R5
R1 R2
R3 R4
R6
Fa0/0
1.1/30
Fa0/0
1.2/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
Fa1/0
1.17/30
F0/0
1.18/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
P-to-P

4. 4. MPLS – LDP - Xconnects
Testing Xconnect on PE R1<==>R6
R1#show xconnect all
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP ac Fa1/0(Ethernet) UP mpls 192.168.0.6:99 UP
R1#show xconnect interface Fa1/0 detail
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP ac Fa1/0(Ethernet) UP mpls 192.168.0.6:99 UP
Interworking: none Local VC label 16
Remote VC label 27
R6#show xconnect all
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP ac Fa0/0(Ethernet) UP mpls 192.168.0.1:99 UP
R6#show xconnect interface Fa0/0 detail
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP ac Fa0/0(Ethernet) UP mpls 192.168.0.1:99 UP
Interworking: none Local VC label 27
Remote VC label 16
VCID99
VCID99
R5
R1 R2
R3 R4
R6
Fa0/1
1.6/30
Fa0/0
1.1/30
Fa0/0
1.2/30 Fa0/1
1.5/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
Fa1/0
1.17/30
F0/0
1.18/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
Local Label 16
Local Label 27
P-to-P

5. 5. MPLS – LDP - Xconnects
Xconnect – Labels Local/Remote & VCID
R1#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 l2ckt(99) 73919 none point2point
23 22 192.168.0.6/32 0 Fa0/1 192.168.1.13
19 192.168.0.6/32 0 Fa0/0 192.168.1.2
Labels on MY LOCAL LOOP
R1 Local Loop (192.168.0.1) Label 23
R6 Local Loop (192.168.0.6) Label 22
Label on DEST LOOP R1 & R6
R1 → R6 fa0/1 use Label 22
R6 → R1 fa0/1 use Label 20
R6#show mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
22 20 192.168.0.1/32 0 Fa0/1 192.168.1.21
27 l2ckt(99) 78453 none point2point
Local Label 16
Local Label 27
VCID99
R5
R1 R2
R3 R4
R6
Fa0/1
1.6/30
Fa0/0
1.1/30
Fa0/0
1.2/30 Fa0/1
1.5/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
Fa1/0
1.17/30
F0/0
1.18/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
L22
L20
P-to-P

6. 6. MPLS – LDP - Xconnects
Xconnect – Labels Local/Remote & VCID
R6 → R1 : Fill in the Blanks
R6#show mpls l2transport vc 99 detail
Local interface: Fa0/0 up, line protocol up, Ethernet up
Destination address: 192.168.0.1, VC ID: 99, VC status: up
Next hop: 192.168.1.21
Output interface: Fa0/1, imposed label stack {20 16}
Create time: 03:33:09, last status change time: 03:33:06
Signaling protocol: LDP, peer 192.168.0.1:0 up
MPLS VC labels: local 27, remote 16
Group ID: local 0, remote 0
MTU: local 1500, remote 1500
Remote interface description: r1-ce7
R6#show xconnect interface fa0/0 detail
XC ST Segment 1 S1 Segment 2 S2
------+-----------------------------+--+----------------------------+--
UP ac Fa0/0(Ethernet) UP mpls 192.168.0.1:99 UP
Interworking: none Local VC label 27
Remote VC label 16
Local Label 16
Local Label 27
VCID99
R5
R1 R2
R3 R4
R6
Fa0/0
1.1/30
Fa0/0
1.2/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
L
P-to-P

7. 7. MPLS – LDP - Xconnects
Xconnect – Labels Local/Remote & VCID
R1#show mpls l2transport vc 99 detail
Local interface: Fa1/0 up, line protocol up, Ethernet up
Destination address: 192.168.0.6, VC ID: 99, VC status: up
Next hop: 192.168.1.13
Output interface: Fa0/1, imposed label stack {22 27}
Create time: 03:04:31, last status change time: 02:59:26
Signaling protocol: LDP, peer 192.168.0.6:0 up
MPLS VC labels: local 16, remote 27
Group ID: local 0, remote 0
MTU: local 1500, remote 1500
Remote interface description: r6-ce8
R1#show xconnect inter fa1/0 detail
XC ST Segment 1 S1 Segment 2 S2
------+------------------------------+--+---------------------------------+--
UP ac Fa1/0(Ethernet) UP mpls 192.168.0.6:99 UP
Interworking: none Local VC label 16
Remote VC label 27
Local Label 16
Local Label 27
VCID99
R5
R1 R2
R3 R4
R6
Fa0/0
1.1/30
Fa0/0
1.2/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
Label
20?
L22
P-to-P

8. 9. MPLS – LDP - Xconnects
Thank You – kjteoh 11/12/2015
Larger Diagram for reference
Be proficient with MPLS-Xconnects
(junos l2ckt) – Next is:
L3VPN-RD-RT - MP-BGP required
Local Label 16
Local Label 27
VCID99P
To
P
R5
R1 R2
R3 R4
R6
Fa0/0
1.1/30
Fa0/0
1.2/30
Fa0/1
1.9/30
Fa0/1
1.10/30
Fa0/1
1.14/30
Fa0/1
1.13/30
F0/1
1.21/30
F0/1
1.22/30
R8 R6
R7
Label
20?
L22