In the following post i will explain how to configure L2 circuit over MPLS network which eventually allow L2 connection between 2 PEs.
Prerequisites
- Determine all of the routers that you want to participate in the circuit, and then complete the initial configuration of their interfaces.
- For all of the routers in the circuit configuration, update the interface configurations to enable participation in the Layer 2 circuit.
- On the interface communicating with the other provider edge (PE) router, specify MPLS and IPv4, and include the IP address. For the loopback interface, specify inet, and include the IP address. For IPv4, designate the loopback interface as primary so it can receive control packets. (Because it is always operational, the loopback interface is best able to perform the control function.)
- On the PE router interface facing the customer edge (CE) router, specify a circuit cross-connect (CCC) encapsulation type. The type of encapsulation depends on the interface type. For example, an Ethernet interface uses ethernet-ccc. (The encapsulation type determines how the packet is constructed for that interface.)
- For all of the routers in the circuit configuration, configure the appropriate protocols.
- MPLS—For PE routers and provider routers, use MPLS to advertise the Layer 2 circuit interfaces that communicate with other PE routers and provider routers.
- BGP—For PE routers, configure a BGP session.
- IGP and a signaling protocol—For PE routers, configure a signaling protocol (either LDP or RSVP) to dynamically set up label-switched paths (LSPs) through the provider network. (LDP routes traffic using IGP metrics.
- In addition, configure an IGP such as OSPF or static routes on the PE routers to enable exchanges of routing information between the PE routers and provider routers. Each PE router's loopback address must appear as a separate route. Do not configure any summarization of the PE router's loopback addresses at the area boundary. Configure the provider network to run OSPF or IS-IS as an IGP, as well as IBGP sessions through either a full mesh or route reflector.
Configure Layer-2 Circuit Juniper
to Cisco
The following steps will explain how to configure an MPLS
Layer-2 VPN, using single interface, to multiple far end interfaces, where both
Juniper and Cisco routers are been used.
Topology setup:
1.
An MPLS network based on
LDP/MPLS, IGP (in my case IS-IS but could be also OSPF) and BGP
2.
3x PE routers (PE1 and PE2
are Juniper J-series and PE3 is Cisco 7206VXR)
3.
3x CPEs
Note that the PE-CE connections are set to trunk mode.
The encapsulation type is depended on the PE to CE connection type, a trunk with tagged VLAN traffic will be in vlan-ccc encapsulation mode where access mode interface will be in ethernet-ccc encapsulation mode.
PE1
Configuration (Juniper router)
Loopback 0 IP address: 155.1.1.1
Interface ge-0/0/2 configured as L2 in trunk mode, connects
to CE
Interface ge-0/0/1 configured as L3, runs LDP, ISIS and BGP,
connects to SP network
1.
Make sure router’s loopback
is configured under mpls and ldp protocols else configure it:
root@PE1# set protocols mpls
interface lo0.0
root@PE1# set protocols ldp
interface lo0.0
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2.
Configure the physical
ingress router interface for 802.1q tagging for a cross-connect:
root@PE1# set interfaces
ge-0/0/2 vlan-tagging
root@PE1# set interfaces
ge-0/0/2 encapsulation vlan-ccc
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3.
Configure the appropriate
interfaces as units under the physical interface:
root@PE1# set interfaces
ge-0/0/2 unit 2900 encapsulation vlan-ccc vlan-id 2900
root@PE1# set interfaces
ge-0/0/2 unit 2077 encapsulation vlan-ccc vlan-id 2077
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4.
Now configure the Layer-2
circuit under protocols:
[edit protocols]
root@PE1# set l2circuit
neighbor 155.1.1.2 interface ge-0/0/2.2900 virtual-circuit-id 2900
root@PE1# set l2circuit
neighbor 155.1.1.2 interface ge-0/0/2.2900 no-control-word
root@PE1# set l2circuit
neighbor 155.1.1.2 interface ge-0/0/2.2900 encapsulation-type ethernet-vlan
root@PE1# set l2circuit
neighbor 155.1.1.2 interface ge-0/0/2.2900 mtu 1500
root@PE1# set l2circuit
neighbor 155.1.1.3 interface ge-0/0/2.2077 virtual-circuit-id 2900
root@PE1# set l2circuit
neighbor 155.1.1.3 interface ge-0/0/2.2077 no-control-word
root@PE1# set l2circuit
neighbor 155.1.1.3 interface ge-0/0/2.2077 encapsulation-type ethernet-vlan
root@PE1# set l2circuit
neighbor 155.1.1.3 interface ge-0/0/2.2077 mtu 1500
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The configurations are per neighbor and for each VLAN
configure a separate interface and interface settings.
5.
Apply commit
root@PE1# commit
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PE2
Configuration (Juniper router)
Loopback 0 IP address: 155.1.1.2
Interface ge-3/0/0 configured as L2 in trunk mode, connects
to CE
Interface ge-0/0/1 configured as L3, runs LDP, ISIS and BGP,
connects to SP network
The configuration is pretty much the same as PE1
1.
Make sure router’s loopback
is configured under mpls and ldp protocols else configure it:
root@PE2# set protocols mpls
interface lo0.0
root@PE2# set protocols ldp
interface lo0.0
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2.
Configure the physical
ingress router interface for 802.1q tagging for a cross-connect:
root@PE2# set interfaces ge-3/0/0
vlan-tagging
root@PE2# set interfaces
ge-3/0/0 encapsulation vlan-ccc
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3.
Configure the appropriate
interfaces as units under the physical interface:
root@PE2# set interfaces ge-3/0/0
unit 2900 encapsulation vlan-ccc vlan-id 2900
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4.
Now configure the Layer-2
circuit under protocols:
[edit protocols]
root@PE2# set l2circuit
neighbor 155.1.1.1 interface ge-3/0/0.2900 virtual-circuit-id 2900
root@PE2# set l2circuit
neighbor 155.1.1.1 interface ge-3/0/0.2900 no-control-word
root@PE2# set l2circuit
neighbor 155.1.1.1 interface ge-3/0/0.2900 encapsulation-type ethernet-vlan
root@PE2# set l2circuit
neighbor 155.1.1.1 interface ge-3/0/0.2900 mtu 1500
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5.
Apply commit
root@PE1# commit
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PE3
Configuration (Cisco router)
Loopback 0 IP address: 155.1.1.3
Interface gi2/0 configured as L2 in trunk mode, connects to
CE
Interface gi0/1 configured as L3, runs LDP, ISIS and BGP,
connects to SP network
1.
Configure the physical
interface:
interface GigaEthernet2/0
no ip address
load-interval 30
duplex full
end
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2.
Configure the logical
interface:
interface GigaEthernet2/0.2077
encapsulation dot1Q 2077
xconnect 155.1.1.1 2077 encapsulation mpls
end
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3.
Save the configuration:
Router(config)# wr
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Verification
Check Layer-2 link status:
Juniper:
root@PE1> show l2circuit
connections extensive
Layer-2 Circuit Connections:
Legend for connection status
(St)
EI -- encapsulation
invalid NP -- interface h/w not
present
MM -- mtu mismatch Dn -- down
EM -- encapsulation
mismatch VC-Dn -- Virtual circuit
Down
CM -- control-word
mismatch Up -- operational
VM -- vlan id mismatch CF -- Call admission control
failure
OL -- no outgoing label IB -- TDM incompatible bitrate
NC -- intf encaps not
CCC/TCC TM -- TDM misconfiguration
BK -- Backup Connection ST -- Standby Connection
CB -- rcvd cell-bundle size
bad SP -- Static Pseudowire
LD -- local site signaled
down RS -- remote site standby
RD -- remote site signaled
down XX -- unknown
Legend for interface
status
Up -- operational
Dn -- down
Neighbor: 155.1.1.2
Interface Type St
Time last up # Up trans
ge-0/0/2.2900(vc 2900) rmt
Up Feb 12 03:35:59 2012 1
Remote PE: 155.1.1.2, Negotiated control-word:
No
Incoming label: 324768, Outgoing label:
319760
Negotiated PW status TLV: No
Local interface: ge-0/0/2.2900, Status: Up,
Encapsulation: VLAN
Connection History:
Feb 12 03:35:59 2012 status update timer
Feb 12 03:35:58 2012 PE route changed
Feb 12 03:35:58 2012 Out lbl Update 319760
Feb 12 03:35:58 2012 In lbl Update 324768
Feb 12 03:35:58 2012 loc intf up ge-0/0/2.2900
Neighbor: 155.1.1.3
Interface Type St
Time last up # Up trans
ge-0/0/2.2077(vc 2077) rmt
Up Feb 13 00:34:09 2012 1
Remote PE: 155.1.1.3, Negotiated control-word: No
Incoming label: 324752, Outgoing label:
42
Negotiated PW status TLV: No
Local interface: ge-0/0/2.2077, Status:
Up, Encapsulation: VLAN
Connection History:
Feb 13 00:34:09 2012 status update timer
Feb 13 00:34:09 2012 PE route changed
Feb 13 00:34:09 2012 Out lbl Update 42
Feb 13 00:34:09 2012 In lbl Update 324752
Feb 13 00:34:09 2012 loc intf up ge-0/0/2.2077
Cisco:
router#show xconnect all
detail
Legend: XC ST=Xconnect State,
S1=Segment1 State, S2=Segment2 State
UP=Up, DN=Down, AD=Admin
Down, IA=Inactive, NH=No Hardware
XC ST Segment 1 S1 Segment 2 S2
------+---------------------------------+--+---------------------------------+--
UP ac Gi2/0.2077 2077(Eth VLAN) UP mpls 155.1.1.1:2077
UP
Interworking: none Local VC label 42
Remote VC label 324752
pw-class:
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Send ICMP on MPLS
root@PE1> ping mpls
l2circuit interface ge-0/0/2.2900 size 1500 count 100
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