Example for Configuring Dynamic BGP VPNv4 Flow Specification

This section provides an example for configuring dynamic BGP VPNv4 Flow Specification to allow BGP VPNv4 Flow Specification routes to be transmitted and traffic filtering policies to be generated. The policies improve security of devices in VPNs.

Networking Requirements

As shown in Figure 1, in a VPN, CE1 belongs to AS 100, while PE1 and Server belong to AS 200. PE1 is an ingress of AS 200. AS 200 communicates with AS 100 through PE1.

The attack source in AS 100 may flow into AS 200 through PE1, posing a threat to AS 200. In this situation, configure dynamic BGP VPNv4 Flow Specification to ensure network security. The operation process is as follows: Deploy a traffic analysis server and establish a BGP VPNv4 Flow Specification peer relationship between the traffic analysis server and PE1. PE1 samples traffic periodically and sends the sampled traffic to the traffic analysis server. The traffic analysis server generates a BGP VPNv4 Flow Specification route based on the characteristics of sampled attack traffic and sends the route to PE1. PE1 converts the route into a traffic policy to filter and control attack traffic, ensuring the proper transition of services in AS 200.

Figure 1 Configuring dynamic BGP VPNv4 Flow Specification

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

Configuration Roadmap

The configuration roadmap is as follows:

Configure an IP address for each interface.
Create a VPN instance on PE1 and Server and bind the VPN instance to the PE1's interface that is connected to CE1.
Establish a BGP VPNv4 Flow Specification peer relationship between PE1 and Server to enable the generated BGP VPNv4 Flow Specification routes to be sent to PE1. Then a traffic policy is generated.

The traffic analysis server is a third-party device, and it must be a BGP VPNv4 Flow Specification peer of another device.

Data Preparation

To complete the configuration, you need the following data:

AS number of CE1 (100) and AS number of PE1, and Server (200)
Name of a VPN instance (vpna)

Procedure

Configure an IP address for each interface.
For detailed configurations, see the configuration files in this example.

Create a VPN instance and bind the VPN instance to the PE1's interface that is connected to CE1.

# Configure PE1.

[~PE1] ip vpn-instance vpna
[*PE1-vpn-instance-vpna] ipv4-family
[*PE1-vpn-instance-vpna-af-ipv4] route-distinguisher 100:1
[*PE1-vpn-instance-vpna-af-ipv4] vpn-target 111:1 export-extcommunity
[*PE1-vpn-instance-vpna-af-ipv4] vpn-target 111:1 import-extcommunity
[*PE1-vpn-instance-vpna-af-ipv4] commit
[~PE1-vpn-instance-vpna-af-ipv4] quit
[~PE1-vpn-instance-vpna] quit
[~PE1] interface GigabitEthernet0/1/0
[~PE1-GigabitEthernet0/1/0] undo shutdown
[*PE1-GigabitEthernet0/1/0] ip binding vpn-instance vpna
[*PE1-GigabitEthernet0/1/0] ip address 10.1.1.2 255.255.255.0
[*PE1-GigabitEthernet0/1/0] commit
[~PE1-GigabitEthernet0/1/0] quit
[~PE1] interface GigabitEthernet0/1/8
[~PE1-GigabitEthernet0/1/8] undo shutdown
[*PE1-GigabitEthernet0/1/8] ip address 10.2.1.1 255.255.255.0
[*PE1-GigabitEthernet0/1/8] commit
[~PE1-GigabitEthernet0/1/8] quit

Configure a BGP VPNv4 Flow Specification peer and disable route authentication.

# Configure PE1.

[~PE1]bgp 200
[*PE1-bgp] peer 10.2.1.2 as-number 200
[*PE1-bgp] vpn-instance vpna
[*PE1-bgp-instance-vpna] quit
[*PE1-bgp] ipv4-flow vpn-instance vpna
[*PE1-bgp-flow-vpna] quit
[*PE1-bgp] ipv4-flow vpnv4
[*PE1-bgp-af-flow-vpnv4] peer 10.2.1.2 enable
[*PE1-bgp-af-flow-vpnv4] commit
[~PE1-bgp-af-flow-vpnv4] quit
[~PE1-bgp] quit

Verify the configuration.

# Check whether BGP VPNv4 Flow Specification peer relationships are established on PE1. The command output shows that BGP VPNv4 Flow Specification peer relationships are established and that the BGP VPN Flow Specification peer relationship is established between CE1 and PE1.

<PE1> display bgp flow vpnv4 all peer
 
 BGP local router ID : 10.1.1.2
 Local AS number : 200
 Total number of peers : 2                 Peers in established state : 2

  Peer            V          AS  MsgRcvd  MsgSent  OutQ  Up/Down       State  PrefRcv
  10.2.1.2        4         200     1076     1067     0 15:30:19 Established        1
   
  Peer of  for vpn instance :

  VPN-Instance vpna, Router ID 10.1.1.2:
  Peer            V          AS  MsgRcvd  MsgSent  OutQ  Up/Down       State  PrefRcv
  10.1.1.1        4         100     1057     1058     0 15:19:07 Established        0

# Check information about the BGP VPNv4 Flow Specification routes received by PE1 and the received BGP VPN Flow Specification routes.

<PE1> display bgp flow vpnv4 all routing-table
 BGP Local router ID is 10.1.1.2
 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 from all PE: 1
 * >  ReIndex : 536870913
      Dissemination Rules:
       Src. Port      : eq 159
       MED      : 0                   PrefVal  : 0                   
       LocalPref: 100                       
       Path/Ogn :  i
    
 VPN-Instance vpna, Router ID 10.1.1.2:

 Total Number of Routes: 1
 * >  ReIndex : 1
      Dissemination Rules:
       Src. Port      : eq 159
       MED      : 0                   PrefVal  : 0                   
       LocalPref: 100                       
       Path/Ogn :  i

# Check the traffic filtering rule carried in the BGP VPNv4 Flow Specification route by specifying ReIndex of the route.

<PE1> display bgp flow vpnv4 all routing-table 536870913
 
 BGP local router ID : 10.1.1.2
 Local AS number : 200
 ReIndex : 536870913
 Order   : 0
 Dissemination Rules :
   Src. Port      : eq 159
 
 BGP flow-vpnv4 routing table entry information of 536870913:
 Route Distinguisher: 200:1
 Match action :
   apply deny
 From: 10.2.1.2 (10.2.1.2) 
 Route Duration: 0d13h59m46s
 Ext-Community: RT <111 : 1>
 AS-path Nil, origin igp, MED 0, localpref 100, pref-val 0, valid, internal, best, pre 255
 Not advertised to any peer yet

Configuration Files

CE1 configuration file

#
sysname CE1
#               
interface GigabitEthernet0/1/0
 undo shutdown  
 ip address 10.1.1.1 255.255.255.0
#               
bgp 100         
 peer 10.1.1.2 as-number 200
 #              
 ipv4-family unicast
  undo synchronization 
  peer 10.1.1.2 enable
 #              
 ipv4-family flow
  peer 10.1.1.2 enable
#               
return

PE1 configuration file

#
sysname PE1
#
ip vpn-instance vpna
 ipv4-family
  route-distinguisher 100:1
  apply-label per-instance
  vpn-target 111:1 export-extcommunity
  vpn-target 111:1 import-extcommunity
#               
interface GigabitEthernet0/1/0
 undo shutdown  
 ip binding vpn-instance vpna
 ip address 10.1.1.2 255.255.255.0
#               
interface GigabitEthernet0/1/8
 undo shutdown  
 ip address 10.2.1.1 255.255.255.0
#               
bgp 200         
 peer 10.2.1.2 as-number 200
 #              
 ipv4-family unicast
  undo synchronization 
  peer 10.2.1.2 enable
 #              
 vpn-instance vpna
 #              
 ipv4-flow vpn-instance vpna
 #              
 ipv4-flow vpnv4
  policy vpn-target
  peer 10.2.1.2 enable
#               
return