Example for Configuring BGP4+ Route Reflection

Configuring BGP4+ RRs simplifies the network configuration because IBGP peers do not need to be fully meshed.

Networking Requirements

In Figure 1, Device B receives an Update packet from its EBGP peer and forwards it to Device C. Device C is an RR and has two clients: Device B and Device D.

Device B and Device D do not need to establish an IBGP connection. After receiving an Update packet from Device B, Device C reflects it to Device D. Similarly, after receiving an Update packet from Device D, Device C reflects it to Device B.

Figure 1 Configuring BGP4+ route reflection

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

Configuration Roadmap

The configuration roadmap is as follows:

Configure basic BGP4+ functions on each router.
Configure an RR and its clients to establish IBGP connections.
Configure Device C as an RR, and then check its routing information.

Data Preparation

To complete the configuration, you need the following data:

Router IDs of Device A, Device B, Device C, and Device D
AS numbers of Device A, Device B, Device C, and Device D

Procedure

Configure an IPv6 address for each interface. For configuration details, see Configuration Files in this section.

Configure basic BGP4+ functions.

# Configure Device A.

[~DeviceA] bgp 100
[*DeviceA-bgp] router-id 1.1.1.1
[*DeviceA-bgp] peer 2001:db8:100::2 as-number 200
[*DeviceA-bgp] ipv6-family unicast
[*DeviceA-bgp-af-ipv6] peer 2001:db8:100::2 enable
[*DeviceA-bgp-af-ipv6] network 2001:db8:1:: 64
[*DeviceA-bgp-af-ipv6] commit
[~DeviceA-bgp-af-ipv6] quit
[~DeviceA-bgp] quit

# Configure Device B.

[~DeviceB] bgp 200
[*DeviceB-bgp] router-id 2.2.2.2
[*DeviceB-bgp] peer 2001:db8:100::1 as-number 100
[*DeviceB-bgp] peer 2001:db8:101::1 as-number 200
[*DeviceB-bgp] ipv6-family unicast
[*DeviceB-bgp-af-ipv6] peer 2001:db8:100::1 enable
[*DeviceB-bgp-af-ipv6] peer 2001:db8:101::1 enable
[*DeviceB-bgp-af-ipv6] peer 2001:db8:101::1 next-hop-local
[*DeviceB-bgp-af-ipv6] commit
[~DeviceB-bgp-af-ipv6] quit
[~DeviceB-bgp] quit

# Configure Device C.

[~DeviceC] bgp 200
[*DeviceC-bgp] router-id 3.3.3.3
[*DeviceC-bgp] peer 2001:db8:101::2 as-number 200
[*DeviceC-bgp] peer 2001:db8:102::2 as-number 200
[*DeviceC-bgp] ipv6-family unicast
[*DeviceC-bgp-af-ipv6] peer 2001:db8:101::2 enable
[*DeviceC-bgp-af-ipv6] peer 2001:db8:102::2 enable
[*DeviceC-bgp-af-ipv6] network 2001:db8:101:: 96
[*DeviceC-bgp-af-ipv6] network 2001:db8:102:: 96
[*DeviceC-bgp-af-ipv6] commit
[~DeviceC-bgp-af-ipv6] quit
[~DeviceC-bgp] quit

# Configure Device D.

[~DeviceD] bgp 200
[*DeviceD-bgp] router-id 4.4.4.4
[*DeviceD-bgp] peer 2001:db8:102::1 as-number 200
[*DeviceD-bgp] ipv6-family unicast
[*DeviceD-bgp-af-ipv6] peer 2001:db8:102::1 enable
[*DeviceD-bgp-af-ipv6] commit
[~DeviceD-bgp-af-ipv6] quit
[~DeviceD-bgp] quit

Configure a BGP4+ RR.

# Configure Device C as an RR, with Device B and Device D as its clients.

[~DeviceC-bgp] ipv6-family unicast
[*DeviceC-bgp-af-ipv6] peer 2001:db8:101::2 reflect-client
[*DeviceC-bgp-af-ipv6] peer 2001:db8:102::2 reflect-client
[*DeviceC-bgp-af-ipv6] commit

Verify the configuration.

# Check the routing table of Device B.

[~DeviceB] display bgp ipv6 routing-table
 BGP Local router ID is 2.2.2.2
 Status codes: * - valid, > - best, d - damped, x - best external, a - add path,
               h - history,  i - internal, s - suppressed, S - Stale
               Origin : i - IGP, e - EGP, ? - incomplete
 RPKI validation codes: V - valid, I - invalid, N - not-found
 Total Number of Routes: 3
 *>  Network  : 2001:db8:1::                             PrefixLen : 64  
     NextHop  : 2001:db8:100::1                          LocPrf    :   
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn : 100i
   i Network  : 2001:db8:101::                           PrefixLen : 96  
     NextHop  : 2001:db8:101::1                          LocPrf    : 100 
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn :  i
 *>i Network  : 2001:db8:102::                           PrefixLen : 96  
     NextHop  : 2001:db8:101::1                          LocPrf    : 100 
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn :  i

# Display the routing table of Device D.

[~DeviceD] display bgp ipv6 routing-table
 BGP Local router ID is 4.4.4.4
 Status codes: * - valid, > - best, d - damped, x - best external, a - add path,
               h - history,  i - internal, s - suppressed, S - Stale
               Origin : i - IGP, e - EGP, ? - incomplete
 RPKI validation codes: V - valid, I - invalid, N - not-found
 Total Number of Routes: 3
 *>i Network  : 2001:db8:1::                             PrefixLen : 64  
     NextHop  : 2001:db8:101::2                          LocPrf    : 100 
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn : 100i
 *>i Network  : 2001:db8:101::                           PrefixLen : 96  
     NextHop  : 2001:db8:102::1                          LocPrf    : 100 
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn :  i
   i Network  : 2001:db8:102::                           PrefixLen : 96  
     NextHop  : 2001:db8:102::1                          LocPrf    : 100 
     MED      : 0                                        PrefVal   : 0
     Label    : 
     Path/Ogn :  i

The preceding command output shows that Device D has learned from Device C the routes advertised by Device A.

Configuration Files

Device A configuration file

#
sysname DeviceA
#
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:db8:100::1/96
#
bgp 100
 router-id 1.1.1.1
 peer 2001:db8:100::2 as-number 200
 #
 ipv6-family unicast
  undo synchronization 
  network 2001:db8:1:: 64
  peer 2001:db8:100::2 enable
#
return

Configuration file of Device B

#
sysname DeviceB
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:101::2/96
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:100::2/96
#
bgp 200
 router-id 2.2.2.2
 peer 2001:db8:100::1 as-number 100
 peer 2001:db8:101::1 as-number 200
 #
 ipv6-family unicast
  undo synchronization 
  peer 2001:db8:100::1 enable
  peer 2001:db8:101::1 enable
  peer 2001:db8:101::1 next-hop-local
#
return

Device C configuration file

#
sysname DeviceC
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:102::1/96
#
interface GigabitEthernet0/1/8
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:101::1/96
#
bgp 200
 router-id 3.3.3.3
 peer 2001:db8:101::2 as-number 200
 peer 2001:db8:102::2 as-number 200
 #
 ipv6-family unicast
  undo synchronization 
  network 2001:db8:101:: 96
  network 2001:db8:102:: 96
  peer 2001:db8:101::2 enable
  peer 2001:db8:101::2 reflect-client
  peer 2001:db8:102::2 enable
  peer 2001:db8:102::2 reflect-client
#
return

Device D configuration file

#
sysname DeviceD
#
interface GigabitEthernet0/1/0
 undo shutdown
 ipv6 enable
 ipv6 address 2001:db8:102::2/96
#
bgp 200
 router-id 4.4.4.4
 peer 2001:db8:102::1 as-number 200
 #
 ipv4-family unicast
  undo synchronization 
 #
 ipv6-family unicast
  undo synchronization 
  peer 2001:db8:102::1 enable
#
return