Example for Configuring VPNv6 FRR

This section describes how to configure VPNv6 FRR in the CE dual-homing networking. If a PE fails, VPNv6 FRR can quickly switch IPv6 VPN traffic to the backup route.

Networking Requirements

VPNv6 FRR can be deployed in the CE dual-homing networking. If the primary route between PEs fails, VPNv6 FRR can quickly switch IPv6 VPN traffic to the backup route.

On the network shown in Figure 1, PE1 learns two routes with the same prefix to the CE from PE2 and PE3. It is required that PE3 be configured as a backup next hop for the IPv6 route on PE1. In this manner, VPN traffic can be quickly switched to PE3 if PE2 becomes faulty.

Figure 1 Configuring VPNv6 FRR

Interfaces 1 through 3 in this example represent GE 0/1/0, GE 0/1/8, and GE 0/1/16, respectively.


Configuration Notes

  • A CE is dual-homed to two PEs, and VPN instances with different RDs are configured on the PEs.
  • In a VPN FRR scenario, after the primary path recovers, traffic switches back to this path. Because the order in which nodes undergo IGP convergence differs, packet loss may occur during the switchback. To resolve this problem, run the route-select delay delay-value command to configure a route selection delay so that traffic is switched back only after forwarding entries on the devices along the primary path are updated. The delay specified using delay-value depends on various factors, such as the number of routes on the devices. Set a proper delay as needed.

Configuration Roadmap

The configuration roadmap is as follows:

  1. Configure OSPF on the MPLS backbone network for IP connectivity between PE1, PE2, and PE3.

  2. Configure MPLS and MPLS LDP both globally and per interface on each node of the MPLS backbone network and establish LDP LSPs.

  3. Configure an IPv6-address-family-supporting VPN instance on PE1, PE2, and PE3, and bind the interface that connects a PE to the CE to the VPN instance on that PE.

  4. Establish an EBGP peer relationship between the CE and PE2, and between the CE and PE3, import IPv6 VPN routes, and establish MP-IBGP peer relationships between PEs.

  5. Configure static BFD for LDP LSP on PE1 and PE2.

  6. Enable VPNv6 auto FRR on PE1.

Data Preparation

To complete the configuration, you need the following data:

  • AS numbers of the PEs and CE

  • Name of the VPN instance configured on each PE and the other attributes of the VPN instance IPv6 address family such as the RD and VPN target

  • Names of the routing policy and ip-prefix configured on PE1

  • BFD configuration name, local discriminator, and remote discriminator

Procedure

  1. Configure IPv4 addresses for interfaces on the backbone network of the VPN and IPv6 addresses for interfaces at the VPN site. For configuration details, see Configuration Files in this section.
  2. Configure OSPF on the MPLS backbone network to ensure IP connectivity on the backbone network. For configuration details, see Configuration Files in this section.
  3. Configure MPLS and MPLS LDP both globally and per interface on each node of the MPLS backbone network and establish LDP LSPs.

    # Configure PE1.

    <PE1> system-view
[~PE1] mpls lsr-id 1.1.1.1
[*PE1] mpls
[*PE1-mpls] quit
[*PE1] mpls ldp
[*PE1-mpls-ldp] quit
[*PE1] interface gigabitEthernet0/1/8
[*PE1-GigabitEthernet0/1/8] mpls
[*PE1-GigabitEthernet0/1/8] mpls ldp
[*PE1-GigabitEthernet0/1/8] quit
[*PE1] interface gigabitEthernet0/1/16
[*PE1-GigabitEthernet0/1/16] mpls
[*PE1-GigabitEthernet0/1/16] mpls ldp
[*PE1-GigabitEthernet0/1/16] quit
[*PE1] commit

    # Configure PE2.

    <PE2> system-view
[~PE2] mpls lsr-id 2.2.2.2
[*PE2] mpls
[*PE2-mpls] quit
[*PE2] mpls ldp
[*PE2-mpls-ldp] quit
[*PE2] interface gigabitEthernet0/1/0
[*PE2-GigabitEthernet0/1/0] mpls
[*PE2-GigabitEthernet0/1/0] mpls ldp
[*PE2-GigabitEthernet0/1/0] quit
[*PE2] commit

    # Configure PE3.

    <PE3> system-view
[~PE3] mpls lsr-id 3.3.3.3
[*PE3] mpls
[*PE3-mpls] quit
[*PE3] mpls ldp
[*PE3-mpls-ldp] quit
[*PE3] interface gigabitEthernet0/1/0
[*PE3-GigabitEthernet0/1/0] mpls
[*PE3-GigabitEthernet0/1/0] mpls ldp
[*PE3-GigabitEthernet0/1/0] quit
[*PE3] commit

    Run the display mpls lsp command on PEs. The command output shows that LSPs are set up between PE1 and PE2, and between PE1 and PE3. The following example uses the command output on PE1.

    [~PE1] display mpls lsp
2021-04-09 01:14:17.813                                                                                                             
Flag after Out IF: (I) - RLFA Iterated LSP, (I*) - Normal and RLFA Iterated LSP                                                     
Flag after LDP FRR: (L) - Logic FRR LSP
-------------------------------------------------------------------------------
                 LSP Information: LDP LSP
-------------------------------------------------------------------------------
FEC                In/Out Label  In/Out IF                      Vrf Name
1.1.1.1/32         3/NULL        -/-
2.2.2.2/32         NULL/3        -/GE0/1/8
2.2.2.2/32         1025/3        -/GE0/1/8
3.3.3.3/32         NULL/3        -/GE0/1/16
3.3.3.3/32         1024/3        -/GE0/1/16

  4. Configure an IPv6-address-family-supporting VPN instance on each PE and bind the interfaces that connect PE2 and PE3 to the CE to the VPN instances on PE2 and PE3.

    # Configure PE1.

    [~PE1] ip vpn-instance vpn1
[*PE1-vpn-instance-vpn1] ipv6-family
[*PE1-vpn-instance-vpn1-af-ipv6] route-distinguisher 100:1
[*PE1-vpn-instance-vpn1-af-ipv6] vpn-target 111:1
[*PE1-vpn-instance-vpn1-af-ipv6] quit
[*PE1-vpn-instance-vpn1] quit
[*PE1] interface loopback2
[*PE1-Loopback2] ip binding vpn-instance vpn1
[*PE1-Loopback2] ipv6 enable
[*PE1-Loopback2] ipv6 address 2001:DB8:8::1 64
[*PE1-Loobpack2] quit
[*PE1] commit

    # Configure PE2.

    [~PE2] ip vpn-instance vpn1
[*PE2-vpn-instance-vpn1] ipv6-family
[*PE2-vpn-instance-vpn1-af-ipv6] route-distinguisher 100:2
[*PE2-vpn-instance-vpn1-af-ipv6] vpn-target 111:1
[*PE2-vpn-instance-vpn1-af-ipv6] quit
[*PE2-vpn-instance-vpn1] quit
[*PE2] interface gigabitethernet0/1/8
[*PE2-GigabitEthernet0/1/8] ip binding vpn-instance vpn1
[*PE2-GigabitEthernet0/1/8] ipv6 enable
[*PE2-GigabitEthernet0/1/8] ipv6 address 2001:DB8:1::2 64
[*PE2-GigabitEthernet0/1/8] quit
[*PE2] commit

    # Configure PE3.

    [~PE3] ip vpn-instance vpn1
[*PE3-vpn-instance-vpn1] ipv6-family
[*PE3-vpn-instance-vpn1-af-ipv6] route-distinguisher 100:3
[*PE3-vpn-instance-vpn1-af-ipv6] vpn-target 111:1
[*PE3-vpn-instance-vpn1-af-ipv6] quit
[*PE3-vpn-instance-vpn1] quit
[*PE3] interface gigabitethernet0/1/8
[*PE3-GigabitEthernet0/1/8] ip binding vpn-instance vpn1
[*PE3-GigabitEthernet0/1/8] ipv6 enable
[*PE3-GigabitEthernet0/1/8] ipv6 address 2001:DB8:3::2 64
[*PE3-GigabitEthernet0/1/8] quit
[*PE3] commit

  5. Establish an EBGP peer relationship between PE2 and the CE, and between PE3 and the CE.

    # Configure PE2.

    [~PE2] bgp 100
[*PE2-bgp] ipv6-family vpn-instance vpn1
[*PE2-bgp6-vpn1] peer 2001:DB8:1::1 as-number 65410
[*PE2-bgp6-vpn1] quit
[*PE2-bgp] quit
[*PE2] commit

    # Configure PE3.

    [~PE3] bgp 100
[*PE3-bgp] ipv6-family vpn-instance vpn1
[*PE3-bgp6-vpn1] peer 2001:DB8:3::1 as-number 65410
[*PE3-bgp6-vpn1] quit
[*PE3-bgp] quit
[*PE3] commit

    # Configure the CE.

    <CE> system-view
[~CE] bgp 65410
[*CE-bgp] router-id 10.10.10.10
[*CE-bgp] peer 2001:DB8:1::2 as-number 100
[*CE-bgp] peer 2001:DB8:3::2 as-number 100
[*CE-bgp] ipv6-family unicast
[*CE-bgp-af-ipv6] peer 2001:DB8:1::2 enable
[*CE-bgp-af-ipv6] peer 2001:DB8:3::2 enable
[*CE-bgp-af-ipv6] network 2001:DB8:0:1:2::1 128
[*CE-bgp-af-ipv6] quit
[*CE-bgp] quit
[*CE] commit

    After completing the configurations, run the display bgp vpnv6 vpn-instance vpn1 peer command on PE2 and PE3. The command output shows that the status of the EBGP peer relationships between the PEs and CE is Established.

    The following example uses the command output on PE2.

    [~PE2] display bgp vpnv6 vpn-instance vpn1 peer
 BGP local router ID : 2.2.2.2
 Local AS number : 100
 Total number of peers : 1                 Peers in established state : 1
  Peer            V    AS  MsgRcvd  MsgSent  OutQ  Up/Down       State PrefRcv
  2001:DB8:1::1   4 65001       46       46     0 00:08:36 Established     5

  6. Establish an MP-IBGP peer relationship between PEs.

    # Configure PE1.

    [~PE1] bgp 100
[*PE1-bgp] peer 2.2.2.2 as-number 100
[*PE1-bgp] peer 2.2.2.2 connect-interface loopback 1
[*PE1-bgp] peer 3.3.3.3 as-number 100
[*PE1-bgp] peer 3.3.3.3 connect-interface loopback 1
[*PE1-bgp] ipv6-family vpnv6
[*PE1-bgp-af-vpnv6] peer 2.2.2.2 enable
[*PE1-bgp-af-vpnv6] peer 3.3.3.3 enable
[*PE1-bgp-af-vpnv6] quit
[*PE1-bgp] quit
[*PE1] commit

    # Configure PE2.

    [~PE2] bgp 100
[*PE2-bgp] peer 1.1.1.1 as-number 100
[*PE2-bgp] peer 1.1.1.1 connect-interface loopback 1
[*PE2-bgp] ipv6-family vpnv6
[*PE2-bgp-af-vpnv6] peer 1.1.1.1 enable
[*PE2-bgp-af-vpnv6] quit
[*PE2-bgp] quit
[*PE2-bgp] commit

    # Configure PE3.

    [~PE3] bgp 100
[*PE3-bgp] peer 1.1.1.1 as-number 100
[*PE3-bgp] peer 1.1.1.1 connect-interface loopback 1
[*PE3-bgp] ipv6-family vpnv6
[*PE3-bgp-af-vpnv6] peer 1.1.1.1 enable
[*PE3-bgp-af-vpnv6] quit
[*PE3-bgp] quit
[*PE3] commit

    After completing the configurations, run the display bgp vpnv6 all peer command on the PEs. The command output shows that the status of the MP-IBGP peer relationship between the PEs is Established.

    The following example uses the command output on PE1.

    [~PE1] display bgp vpnv6 all peer
 BGP local router ID : 10.10.1.1
 Local AS number : 100
 Total number of peers : 2                 Peers in established state : 2

  Peer            V          AS  MsgRcvd  MsgSent  OutQ  Up/Down       State  PrefRcv
  2.2.2.2         4         100       29       26     0 00:20:08 Established       2
  3.3.3.3         4         100       18       17     0 00:11:32 Established       1

  7. Configure Static BFD for LDP LSP.

    # Configure Static BFD for LDP LSP on the PE1.

    [~PE1] bfd
[*PE1-bfd] quit
[*PE1] bfd for_ldp_lsp bind ldp-lsp peer-ip 2.2.2.2 nexthop 10.10.1.2 interface gigabitethernet0/1/8
[*PE1-bfd-session-for_ldp_lsp] discriminator local 10
[*PE1-bfd-session-for_ldp_lsp] discriminator remote 20
[*PE1-bfd-session-for_ldp_lsp] process-pst
[*PE1-bfd-session-for_ldp_lsp] commit
[~PE1-bfd-session-for_ldp_lsp] quit

    # Configure Static BFD for LDP LSP on the PE2.

    [~PE2] bfd
[*PE2-bfd] quit
[*PE2] bfd for_ldp_lsp bind ldp-lsp peer-ip 1.1.1.1 nexthop 10.10.1.1 interface gigabitethernet0/1/0
[*PE2-bfd-session-for_ldp_lsp] discriminator local 20
[*PE2-bfd-session-for_ldp_lsp] discriminator remote 10
[*PE2-bfd-session-for_ldp_lsp] commit
[~PE2-bfd-session-for_ldp_lsp] quit

    # After completing the configuration, run the display bfd session all verbose command on the PE1 and PE2. Up is displayed in the State field, and LDP_LSP is displayed in the BFD Bind Type field.

  8. Enable VPNv6 auto FRR.

    # Configure PE1.

    [~PE1] bgp 100
[~PE1-bgp] ipv6-family vpn-instance vpn1
[*PE1-bgp6-vpn1] auto-frr
[*PE1-bgp6-vpn1] route-select delay 300
[*PE1-bgp6-vpn1] quit
[*PE1-bgp] quit
[*PE1] commit

  9. Verify the configuration.

    After completing the configurations, run the display ipv6 routing-table vpn-instance verbose command on PE1. The command output shows the backup next hop, backup label, and backup tunnel ID of the IPv6 VPN route.

    [~PE1] display ipv6 routing-table vpn-instance vpn1 2001:DB8:2::1 128 verbose
Routing Table : vpn1
Summary Count : 1

Destination  : 2001:DB8:2::1                       PrefixLength : 128
NextHop      : 2.2.2.2                             Preference   : 255
Neighbour    : ::                                      ProcessID    : 0
Label        : 4099                                    Protocol     : IBGP
State        : Active Adv Relied                       Cost         : 0
Entry ID     : 0                                       EntryFlags   : 0x00000000
Reference Cnt: 0                                       Tag          : 0
Priority     : low                                     Age          : 450sec
IndirectID   : 0x5A00006E
RelayNextHop : ::                                      TunnelID     : 0x0000000001004c4b42
Interface    : LDP LSP                                 Flags        : RD
BkNextHop   : 3.3.3.3                                 BkInterface  : LDP LSP
BkLabel     : 4098                                     BkTunnelID   : 0x0
BkPETunnelID: 0x0000000001004c4b43                    BkIndirectID : 0x5A000070

Configuration Files

  • PE1 configuration file

    #
 sysname PE1
#
ip vpn-instance vpn1
 ipv6-family
  route-distinguisher 100:1
  apply-label per-instance
  vpn-target 111:1 export-extcommunity
  vpn-target 111:1 import-extcommunity
#
bfd
#
mpls lsr-id 1.1.1.1
#
mpls
#
mpls ldp
#
interface GigabitEthernet0/1/8
 undo shutdown
 ip address 10.10.1.1 255.255.255.252
 mpls
 mpls ldp
#
interface GigabitEthernet0/1/16
 undo shutdown
 ip address 10.20.1.1 255.255.255.252
 mpls
 mpls ldp
#
interface LoopBack1
 ip address 1.1.1.1 255.255.255.255
#
interface LoopBack2
 ip binding vpn-instance vpn1
ipv6 enable
ipv6 address 2001:DB8:8::1/64
#
bgp 100
 peer 2.2.2.2 as-number 100
 peer 2.2.2.2 connect-interface LoopBack1
 peer 3.3.3.3 as-number 100
 peer 3.3.3.3 connect-interface LoopBack1
 #
 ipv4-family unicast
  undo synchronization
  peer 2.2.2.2 enable
  peer 3.3.3.3 enable
#
 ipv6-family vpnv6
  policy vpn-target
  peer 2.2.2.2 enable
  peer 3.3.3.3 enable
#
 ipv6-family vpn-instance vpn1
 auto-frr
 route-select delay 300
#
ospf 1
 area 0.0.0.0
  network 10.10.1.0 0.0.0.3
  network 10.20.1.0 0.0.0.3
  network 1.1.1.1 0.0.0.0
#
bfd for_ldp_lsp bind ldp-lsp peer-ip 2.2.2.2 nexthop 10.10.1.2 interface gigabitethernet0/1/8
 discriminator local 10
 discriminator remote 20
 process-pst
#
return

  • PE2 configuration file

    #
 sysname PE2
#
ip vpn-instance vpn1
 ipv6-family
  route-distinguisher 100:2
  apply-label per-instance
  vpn-target 111:1 export-extcommunity
  vpn-target 111:1 import-extcommunity
#
bfd
#
mpls lsr-id 2.2.2.2
#
mpls
#
mpls ldp
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 10.10.1.2 255.255.255.252
 mpls
 mpls ldp
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable 
 ip binding vpn-instance vpn1
 ipv6 address 2001:DB8:1::2/64
#
interface LoopBack1
 ip address 2.2.2.2 255.255.255.255
#
bgp 100
 peer 1.1.1.1 as-number 100
 peer 1.1.1.1 connect-interface LoopBack1
 #
 ipv4-family unicast
  undo synchronization
  peer 1.1.1.1 enable
#
 ipv6-family vpnv6
  policy vpn-target
  peer 1.1.1.1 enable
#
 ipv6-family vpn-instance vpn1
  peer 2001:DB8:1::1 as-number 65410
  import-route direct
#
ospf 1
 area 0.0.0.0
  network 10.10.1.0 0.0.0.3
  network 2.2.2.2 0.0.0.0
#
bfd for_ldp_lsp bind ldp-lsp peer-ip 1.1.1.1 nexthop 10.10.1.1 interface gigabitethernet0/1/0
 discriminator local 20
 discriminator remote 10
#
return

  • PE3 configuration file

    #
 sysname PE3
#
ip vpn-instance vpn1
 ipv6-family
  route-distinguisher 100:3
  apply-label per-instance
  vpn-target 111:1 export-extcommunity
  vpn-target 111:1 import-extcommunity
#
mpls lsr-id 3.3.3.3
#
mpls
#
mpls ldp
#
interface GigabitEthernet0/1/0
 undo shutdown
 ip address 10.20.1.2 255.255.255.252
 mpls
 mpls ldp
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable 
 ip binding vpn-instance vpn1
 ipv6 address 2001:DB8:3::2/64
#
interface LoopBack1
 ip address 3.3.3.3 255.255.255.255
#
bgp 100
 peer 1.1.1.1 as-number 100 
 peer 1.1.1.1 connect-interface LoopBack1
 #
 ipv4-family unicast
  undo synchronization
  peer 1.1.1.1 enable
#
 ipv6-family vpnv6
  policy vpn-target
  peer 1.1.1.1 enable
#
 ipv6-family vpn-instance vpn1
  peer 2001:DB8:3::1 as-number 65410
#
ospf 1
 area 0.0.0.0
  network 10.20.1.0 0.0.0.3
  network 3.3.3.3 0.0.0.0
#
Return

  • CE configuration file

    #
 sysname CE
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:DB8:1::1/64
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:DB8:3::1/64
#
interface LoopBack1
 ipv6 enable
 ipv6 address 2001:DB8:2::1/128
#
bgp 65410
 router-id 10.10.10.10
 peer 2001:DB8:1::2 as-number 100
 peer 2001:DB8:3::2 as-number 100
 #
 ipv4-family unicast
  undo synchronization
 #
  ipv6-family unicast
   undo synchronization
   network 2001:DB8:0:1:2::1 128
   peer 2001:DB8:1::2 enable
   peer 2001:DB8:3::2 enable
#
return
Parent Topic: Configuration Examples for BGP/MPLS IPv6 VPN
Copyright © Huawei Technologies Co., Ltd.
Copyright © Huawei Technologies Co., Ltd.
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