Example: ATM2 IQ-Based Layer 2 Circuit Configuration
Figure 1 shows a similar network topology to our previous two examples. In this example, Routers PE1 and PE2 use ATM cell-relay mode on a CE-facing interface and ATM AAL5 mode on a second CE-facing interface.
On Router CE1, configure the ATM2 IQ interfaces
to handle ATM traffic. Interface at-0/0/1 handles standard
ATM traffic while interface at-0/0/2 handles AAL5 traffic.
Router CE1
[edit]
interfaces {
at-0/0/1 {
description "to PE1 at-0/1/0";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
vci 32;
family inet {
address 10.1.1.1/30;
}
}
}
at-0/0/2 {
description "to PE1 at-1/2/0";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-vc-mux;
vci 32;
family inet {
address 10.2.2.1/30;
}
}
}
}
On Router PE1, configure the ATM2 IQ-based CE-facing interfaces:
one with ATM cell-relay mode CCC encapsulation and the other with
ATM VC multiplexing CCC encapsulation. Also enable the corresponding
Layer 2 circuit modes at the [edit chassis] hierarchy
level. In this case, you must configure cell-relay mode on Physical
Interface Card (PIC) 1 in Flexible PIC Concentrator (FPC) 0 and AAL5 mode on PIC 2 in FPC 1.
Establish your Layer 2 circuit with configuration of the l2circuit statement at the [edit protocols] hierarchy
level. Remember to include in your Layer 2 circuit configuration
the IP address of your remote PE neighbor (usually the loopback address
of the neighbor), the interfaces connected to the CE router, and a
virtual circuit identifier for each VC. In this case, you will establish
one VC for cell-relay mode traffic and a second VC for AAL5 traffic.
Then, configure MPLS, LDP, and an IGP (such as OSPF) to enable signaling
for your Layer 2 circuit.
Router PE1
[edit]
chassis {
fpc 0 {
pic 1 {
atm-l2circuit-mode {
cell; # This dedicates FPC 0 PIC 1 to cell-relay mode.
}
}
}
fpc 1 {
pic 2 {
atm-l2circuit-mode {
aal5; # This dedicates FPC 1 PIC 2 to AAL5 mode.
}
}
}
}
interfaces {
at-0/1/0 {
description "to CE1 at-0/0/1";
encapsulation atm-ccc-cell-relay; # Cell-relay requires cell-relay encapsulation.
atm-options {
cell-bundle-size 4; # This sets the cell bundle size for the interface.
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-ccc-cell-relay; # Encapsulation for the logical interface.
vci 32;
cell-bundle-size 10; # The cell bundle size for the logical interface overrides
} # the physical interface setting.
}
at-1/2/0 {
description "to CE1 at-0/0/2";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-ccc-vc-mux; # AAL5 requires CCC VC MUX encapsulation.
vci 32;
}
}
so-0/1/0 {
description "to P0 so-0/0/0";
unit 0 {
family inet {
address 192.168.245.22/30;
}
family mpls; # Include the MPLS family on core-facing interfaces.
}
}
lo0 {
unit 0 {
family inet {
address 10.255.17.2/32;
}
}
}
}
protocols {
ospf {
traffic-engineering;
area 0.0.0.0 {
interface so-0/1/0.0;
interface lo0.0;
}
}
ldp { # LDP is required as the signaling protocol for Layer 2 circuits.
interface so-0/1/0.0;
interface lo0.0;
}
l2circuit {
neighbor 10.255.17.4 { # This points to the loopback of the PE neighbor.
interface at-0/1/0.32 { # Here you include the local CE-facing interface.
virtual-circuit-id 1; # Be sure this ID matches the ID of your PE neighbor.
}
}
neighbor 10.255.17.4 { # This points to the loopback of the PE neighbor.
interface at-1/2/0.32 { # Here you include the local CE-facing interface.
virtual-circuit-id 2; # Be sure this ID matches the ID of your PE neighbor.
}
}
}
}
On Router P0, configure LDP, MPLS, and OSPF on the interfaces connected to the PE routers. The core router provides the MPLS backbone needed to tunnel Layer 2 traffic from the ingress PR router to the egress PE router.
Router P0
[edit]
interfaces {
so-0/0/0 {
description "to PE1 so-0/1/0";
unit 0 {
family inet {
address 192.168.245.21/30;
}
family mpls; # Include the MPLS family on core interfaces.
}
}
so-0/2/1 {
description "to PE2 so-1/1/0";
unit 0 {
family inet {
address 192.168.245.17/30;
}
family mpls; # Include the MPLS family on core interfaces.
}
}
lo0 {
unit 0 {
family inet {
address 10.255.17.3/32;
}
}
}
}
protocols {
ospf {
traffic-engineering;
area 0.0.0.0 {
interface so-0/0/0.0;
interface so-0/2/1.0;
}
}
ldp { # LDP is required as the signaling protocol for Layer 2 circuits.
interface so-0/0/0.0;
interface so-0/2/1.0;
}
}
On Router PE2, complete the Layer 2 circuit by configuring statements to match those previously set on Router PE1.
Configure the ATM2 IQ-based CE-facing interfaces: one with ATM
cell-relay mode CCC encapsulation and the other with ATM VC multiplexing
CCC encapsulation. Also enable the corresponding Layer 2 circuit
modes at the [edit chassis] hierarchy level. In this case,
you must configure cell-relay mode on PIC 1 in FPC 0 and AAL5 mode on PIC 2 in FPC 1.
Complete your Layer 2 circuit with configuration of the l2circuit statement at the [edit protocols] hierarchy
level. Remember to include in your Layer 2 circuit configuration
the IP address of your remote PE neighbor (Router PE1), the interfaces
connected to the CE router, and a virtual circuit identifier for each
VC. In this case, you will establish one VC for cell-relay mode traffic
and a second VC for AAL5 traffic. Then, configure MPLS, LDP, and an
IGP (such as OSPF) to enable signaling for your Layer 2 circuit.
Router PE2
[edit]
chassis {
fpc 0 {
pic 1 {
atm-l2circuit-mode {
cell; # This dedicates FPC 0 PIC 1 to cell-relay mode.
}
}
}
fpc 1 {
pic 2 {
atm-l2circuit-mode {
aal5; # This dedicates FPC 1 PIC 2 to AAL5 mode.
}
}
}
}
interfaces {
at-0/1/1 {
description "to CE2 at-1/0/1";
encapsulation atm-ccc-cell-relay; # Cell-relay requires cell-relay encapsulation.
atm-options {
cell-bundle-size 4; # This sets the cell bundle size for the physical interface.
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-ccc-cell-relay; # Also configure the encapsulation
vci 32; # on the logical interface.
cell-bundle-size 10; # The cell bundle size for the logical interface overrides
} # the physical interface setting.
}
at-1/2/1 {
description "to CE2 at-1/0/2";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-ccc-vc-mux; # AAL5 requires CCC VC MUX encapsulation.
vci 32;
}
}
so-1/1/0 {
description "to P0 so-0/2/1";
unit 0 {
family inet {
address 192.168.245.18/30;
}
family mpls; # Include the MPLS family on core-facing interfaces.
}
}
lo0 {
unit 0 {
family inet {
address 10.255.17.4/32;
}
}
}
}
protocols {
ospf {
traffic-engineering;
area 0.0.0.0 {
interface so-1/1/0.0;
interface lo0.0;
}
}
ldp { # LDP is required as the signaling protocol for Layer 2 circuits.
interface so-1/1/0.0;
interface lo0.0;
}
l2circuit {
neighbor 10.255.17.2 { # This points to the loopback of the PE neighbor.
interface at-0/1/1.32 { # Here you include the local CE-facing interface.
virtual-circuit-id 1; # Be sure this ID matches the ID of your PE neighbor.
}
}
neighbor 10.255.17.2 { # This points to the loopback of the PE neighbor.
interface at-1/2/1.32 { # Here you include the local CE-facing interface.
virtual-circuit-id 2; # Be sure this ID matches the ID of your PE neighbor.
}
}
}
}
On Router CE2, configure the ATM2 IQ interfaces to handle
ATM traffic. Interface at-1/0/1 handles standard ATM traffic
while interface at-1/0/2 handles AAL5 traffic.
Router CE2
[edit]
interfaces {
at-1/0/1 {
description "to PE2 at-0/1/1";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
vci 32;
family inet {
address 10.1.1.2/30;
}
}
}
at-1/0/2 {
description "to PE2 at-1/2/1";
atm-options {
pic-type atm2; # Layer 2 circuits are compatible with
vpi 0; # ATM2 IQ interfaces.
}
unit 0 {
encapsulation atm-vc-mux;
vci 32;
family inet {
address 10.2.2.2/30;
}
}
}
}
Verifying Your Work
To verify proper operation of Layer 2 circuits, use the following commands:
ping mpls l2circuit interface interface-nameping mpls l2circuit virtual-circuit virtual-circuit-id neighborip-addressshow l2circuit connections
Options:
[brief] | [down] | [extensive] | [history] | [instance] | [local-site] | [remote-site] |[status] | [summary] | [up] | [up-down]show interfacesshow route table l2circuit.0show ldp database l2circuit detail
This is what the operational command output looks like for cell-relay mode on Router PE1:
user@PE1> show l2circuit connections
Layer-2 Circuit Connections:
Legend for connection status (St)
EI -- encapsulation invalid NP -- interface not present
MM -- mtu mismatch Dn -- down
EM -- encapsulation mismatch VC-Dn -- Virtual circuit Down
CM -- control-word mismatch Up -- operational
OL -- no outgoing label XX -- unknown
NC -- intf encaps not CCC/TCC
Legend for interface status
Up -- operational
Dn -- down
Neighbor: 10.255.17.4
Interface Type St Time last up # Up trans
at-0/1/0.0 (vc 32) rmt Up Jan 22 15:15:52 2003 1
Local interface: at-0/1/0.0, Status: Up, Encapsulation: ATM CELL (VC Mode)
Remote PE: 10.255.17.4, Negotiated control-word: Yes (Non-null)
Incoming label: 100000, Outgoing label: 100000
user@PE1> show route table l2circuit.0 detail
l2circuit.0: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
10.255.17.4:CtrlWord:9:32:Local/96 (1 entry, 1 announced)
*L2CKT Preference: 7
Next hop: via so-0/2/0.0 weight 1, selected
Label-switched-path PE1-PE2
Protocol next hop: 10.255.17.4 Indirect next hop: 85135e8 367
State: <Active Int>
Local AS: 69
Age: 2:34
Task: l2 circuit
Announcement bits (1): 0-LDP
AS path: I
VC Label 100000, MTU 0, cell-bundle size 80
10.255.17.4:CtrlWord:9:32:Remote/96 (1 entry, 1 announced)
*LDP Preference: 9
Next hop type: Discard
State: <Active Int>
Local AS: 69
Age: 28:11
Task: LDP
Announcement bits (1): 1-l2 circuit
AS path: I
VC Label 100000, MTU 0, cell-bundle size 80
user@PE1> show interfaces at-0/1/0.0 extensive
Logical interface at-0/1/0.0 (Index 66) (SNMP ifIndex 40) (Generation 4)
Flags: Point-To-Point SNMP-Traps Encapsulation: ATM-CCC-Cell-Relay
L2 circuit cell bundle size: 10 , bundle timeout: 125 usec, timeout count: 0
L2 circuit out-of-sequence count: 0
Traffic statistics:
[...]
user@PE1> show interfaces media at-0/1/0
Physical interface: at-0/1/0, Enabled, Physical link is Up
Interface index: 154, SNMP ifIndex: 50
Link-level type: ATM-CCC-Cell-Relay, MTU: 4482, Clocking: Internal, SONET mode,
L2 circuit mode: Cell, Speed: OC12, Loopback: None
[...]
user@PE1> show ldp database l2circuit detail
Input label database, 10.255.17.2:0--10.255.17.4:0
Label Prefix
100000 L2CKT CtrlWord ATM CELL (VC Mode) VC 32
Cell bundle size: 80
State: Active
Age: 9:48
Output label database, 10.255.17.2:0--10.255.17.4:0
Label Prefix
100000 L2CKT CtrlWord ATM CELL (VC Mode) VC 32
Cell bundle size: 80
State: Active
Age: 9:48
This is what the operational command output looks like on Router PE1 if AAL5 mode is used:
user@PE1> show l2circuit connections
Layer-2 Circuit Connections:
Legend for connection status (St)
EI -- encapsulation invalid NP -- interface not present
MM -- mtu mismatch Dn -- down
EM -- encapsulation mismatch VC-Dn -- Virtual circuit Down
CM -- control-word mismatch Up -- operational
OL -- no outgoing label XX -- unknown
NC -- intf encaps not CCC/TCC
Legend for interface status
Up -- operational
Dn -- down
Neighbor: 10.255.17.4
Interface Type St Time last up # Up trans
at-1/2/0.0 (vc 32) rmt Up Feb 18 18:00:00 2003 1
Local interface: at-1/2/0.0, Status: Up, Encapsulation: ATM AAL5
Remote PE: 10.255.17.4, Negotiated control-word: Yes (Non-null)
Incoming label: 100016, Outgoing label: 100032
user@PE1> show interfaces media at-0/1/0
Physical interface: at-0/1/0, Enabled, Physical link is Up
Interface index: 154, SNMP ifIndex: 50
Link-level type: ATM-PVC, MTU: 4482, Clocking: Internal, SONET mode,
L2 circuit mode: AAL5, Speed: OC12, Loopback: None, Payload scrambler: Enabled
[...]
user@PE1> show interfaces at-1/2/0.0 extensive
Logical interface at-1/2/0.0 (Index 68) (SNMP ifIndex 40) (Generation 38)
Flags: Point-To-Point SNMP-Traps Encapsulation: ATM-CCC-VCMUX
L2 circuit out-of-sequence count: 0
Traffic statistics:[...]