Example for Configuring LB for a PW

This section provides an example for configuring loopback (LB) for a pseudo wire (PW).

Networking Requirements

On the network shown in Figure 1, LSRA, LSRB, and LSRC are connected using a PW built over a bidirectional label switched path (LSP). The following deployment is made to ensure the connectivity and correct packet forwarding between LSRA and LSRC:

LSRA and LSRC serve as MEPs.
LSRB serves as a MIP.

LB can be used on a MEP to check the following items:

Reachability of the RMEP
Round-trip delay in the communication between the MEP and RMEP
Loss of ping packets between the MEP and RMEP

LB counts only the ping packets that are lost after being sent out, providing a rough packet loss ratio of the link between MEPs. The LM function can be used to obtain the accurate packet loss ratio of the link between MEPs.

Figure 1 PW over a bidirectional LSP

Interfaces 1 through 2 in this example are GE 0/1/0 and GE 0/1/8, respectively.

**Table 1** Interfaces and IP addresses
Device	Interface	IP Address
LSRA	Loopback1	1.1.1.1/32
LSRA	GigabitEthernet0/1/0	2.1.1.1/24
LSRB	Loopback1	2.2.2.2/32
	GigabitEthernet0/1/0	2.1.1.2/24
	GigabitEthernet0/1/8	3.2.1.1/24
LSRC	Loopback1	3.3.3.3/32
LSRC	GigabitEthernet0/1/8	3.2.1.2/24

Configuration Roadmap

The configuration roadmap is as follows:

Create a maintenance entity (ME) instance and bind it to a PW.
Enable LB.

Data Preparation

To complete the configuration, you need the following data:

MEG name
ID of the virtual circuit (VC) bound to the ME

Procedure

Configure a PW over a bidirectional LSP.
For configuration details, see "Configuration Examples" in HUAWEI NetEngine 8000 F SeriesRouter Configuration Guide - VPN or "Configuration Files" in this section.

Create an ME instance and bind it to the PW.

# Create an ME instance named test on LSRA and bind it to the PW.

[~LSRA] mpls-tp meg test
[*LSRA-mpls-tp-meg-test] me l2vc peer-ip 3.3.3.3 vc-id 30000 vc-type vlan mep-id 1 remote-mep-id 2

# Create an ME instance named test on LSRC and bind it to the PW.

[~LSRC] mpls-tp meg test
[*LSRC-mpls-tp-meg-test] me l2vc peer-ip 1.1.1.1 vc-id 30000 vc-type vlan mep-id 2 remote-mep-id 1

Enable LB.

LB can be used to monitor the connectivity between a MEP and its RMEP or a MIP. In this example, LB is used to monitor the connectivity between LSRA and LSRC.

Enable LB on LSRA.

<LSRA> ping meg test
  PING test: 9 data bytes, press CTRL_C to break
    Reply from test: bytes=9, Sequence=1 time=100 ms
    Reply from test: bytes=9, Sequence=2 time=90 ms
    Reply from test: bytes=9, Sequence=3 time=100 ms
    Reply from test: bytes=9, Sequence=4 time=90 ms
    Reply from test: bytes=9, Sequence=5 time=100 ms
  --- ping statistics ---
    5 packet (s) transmitted
    5 packet (s) received
    0.00% packet loss
    round-trip min/avg/max 90/96/100 ms

Configuration Files

LSRA configuration file

#
 sysname LSRA
#
 mpls lsr-id 1.1.1.1
 mpls
  mpls te
#
 mpls l2vpn
#
 bidirectional static-cr-lsp ingress Tunnel10
  forward nexthop 2.1.1.2 out-label 20
  backward in-label 20
#
pw-template tpatoc
 peer-address 3.3.3.3
 control-word
 tnl-policy tpatoc
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 2.1.1.1 255.255.255.0
 mpls
 mpls te
#
interface GigabitEthernet0/1/0.1
 vlan-type dot1q 1
 mpls
 mpls static-l2vc pw-template tpatoc 30000 transmit-vpn-label 101 receive-vpn-label 101
#
interface LoopBack1
 ip address 1.1.1.1 255.255.255.255
#
interface Tunnel10
 ip address unnumbered interface LoopBack1
 tunnel-protocol mpls te
 destination 2.2.2.2
 mpls te signal-protocol cr-static
 mpls te tunnel-id 100
 mpls te bidirectional
 mpls te reserved-for-binding
#
 ip route-static 2.2.2.2 255.255.255.255 2.1.1.2
 ip route-static 3.3.3.3 255.255.255.255 2.1.1.2
#
tunnel-policy tpatoc
 tunnel binding destination 2.2.2.2 te Tunnel10
#
 mpls-tp meg test
  me l2vc peer-ip 3.3.3.3 vc-id 30000 vc-type vlan mep-id 1 remote-mep-id 2
#
return

LSRB configuration file

#
 sysname LSRB
#
 mpls lsr-id 2.2.2.2
 mpls
  mpls te
#
 bidirectional static-cr-lsp transit lsp1
  forward in-label 20 nexthop 3.2.1.2 out-label 40
  backward in-label 16 nexthop 2.1.1.1 out-label 20
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 2.1.1.2 255.255.255.0
 mpls
 mpls te
 ais enable
#
interface GigabitEthernet0/1/8
 undo shutdown
 ip address 3.2.1.1 255.255.255.0
 mpls
 mpls te
 ais enable
#
interface LoopBack1
 ip address 2.2.2.2 255.255.255.255
#
 ip route-static 1.1.1.1 255.255.255.255 2.1.1.1
 ip route-static 3.3.3.3 255.255.255.255 3.2.1.2
#
return

LSRC configuration file

#
 sysname LSRC
#
 mpls lsr-id 3.3.3.3
 mpls
  mpls te
#
 mpls l2vpn
#
 bidirectional static-cr-lsp egress lsp1
  forward in-label 40 lsrid 1.1.1.1 tunnel-id 100
  backward nexthop 3.2.1.1 out-label 16
#
pw-template tpctoa
 peer-address 1.1.1.1
 control-word
 tnl-policy tpctoa
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 3.2.1.2 255.255.255.0
 mpls
 mpls te
#
interface GigabitEthernet0/1/0.1
 vlan-type dot1q 1
 mpls static-l2vc pw-template tpctoa 30000 transmit-vpn-label 101 receive-vpn-label 101
#
interface LoopBack1
 ip address 3.3.3.3 255.255.255.255
#
interface Tunnel20
 ip address unnumbered interface LoopBack1
 tunnel-protocol mpls te
 destination 1.1.1.1
 mpls te signal-protocol cr-static
 mpls te tunnel-id 200
 mpls te passive-tunnel
 mpls te binding bidirectional static-cr-lsp egress lsp1
 mpls te reserved-for-binding
#
 ip route-static 1.1.1.1 255.255.255.255 3.2.1.1
 ip route-static 2.2.2.2 255.255.255.255 3.2.1.1
#
tunnel-policy tpctoa
 tunnel binding destination 1.1.1.1 te Tunnel20
#
 mpls-tp meg test
  me l2vc peer-ip 1.1.1.1 vc-id 30000 vc-type vlan mep-id 2 remote-mep-id 1
#
return