Configuring BGP 4+ΒΆ

  1. Start BGP:

    router{}edit conf myconfig
    router{conf:myconfig}rtg
    router{conf:myconfig-rtg}router bgp ASN
    router{conf:myconfig-rtg}exit
    
    ASN

    ASN of your local AS

    Note

    You can also disable BGP:

    router{conf:myconfig-rtg}delete router bgp ASN
    router{conf:myconfig-rtg}exit
    
  2. Connect to a remote BGP router in the BGP context:

    router{conf:myconfig-rtg-bgp}neighbor A:D::D:R remote-as ASN
    
    A:D::D:R

    ipv6| address of the remote BGP router.

    ASN

    ASN of the remote BGP router.

    Note

    In the eBGP 4+ case, the remote BGP router should be a direct next hop of your local BGP router. Otherwise you are trying to configure a multihop BGP peering.

  3. Activate the IPv6 address family support:

    Multi-protocol BGP 4 (MP-BGP) can transport any kind of network prefixes such as IPv4 or IPv6 prefixes. By default, only the IPv4 transport is enabled. To enable the BGP 4+, you have to create the context address-family ipv6, and then BGP 4+ is activated only with the neighbors that are listed within the IPv6 address family.

Example

  1. Activate BGP 4+ with the neighbor 2001:8::1 of the ASN 100:

    router{conf:myconfig-rtg-bgp}address-family ipv6
    router{conf:myconfig-rtg-bgp-ipv6}neighbor A:D::D:R activate
    
    A:D::D:R

    IPv6 address of the remote BGP router.

    Note

    You can also disable the BGP 4+ peering:

    router{conf:myconfig-rtg-bgp}address-family ipv6
    router{conf:myconfig-rtg-bgp-ipv6}neighbor A:D::D:R deactivate
    
  2. Announce the prefixes in the IPv6 address family of the bgp context:

    router{conf:myconfig-rtg-bgp-ipv6}network A:D::/M
    
    A:D::

    IPv6 network prefix that the router can reach.

    M

    Length of this network prefix.

    Tip

    Announce only the network prefixes that your router can reach. Moreover, to avoid a routing loop, a black-hole route or a reject route has to be configured.

  3. Configure BGP 4+:

    We will illustrate this step by the basic following example where we configure two routers belonging to the same AS (AS65530). It is an iBGP 4+ peering example.

    ../../../../../_images/bgp-4-plus-basic-configuration.png

    Figure 25 - BGP 4+ basic configuration

    rt3

    [...]
       router bgp 65530
         bgp router-id 10.1.1.3
         neighbor 3ffe::cc00:2 remote-as 65530
         neighbor 2001:500::4 remote-as 65530
         address-family ipv6
           neighbor 2001:500::4 activate
           neighbor 3ffe::cc00:2 activate
           network 2001:500::/64
         exit
    [...]
    

    rt4

    [...]
    router bgp 65530
      bgp router-id 10.1.1.4
      neighbor 3ffe::cc00:1 remote-as 65530
      neighbor 2001:500::3 remote-as 65530
      address-family ipv6
        neighbor 2001:500::3 activate
        neighbor 3ffe::cc00:1 activate
        network 2001:500::/64
      exit
    [...]
    
  4. Check the TCP connection of BGP, type the command show routing ipv6 bgp summary:

    rt3

    rt3{}show routing ipv6 bgp summary
    BGP router identifier 10.1.1.3, local ASN 65530
    1 BGP AS-PATH entries
    0 BGP community entries
    Neighbor      V  AS     MsgRcvd  MsgSent  TblVer  InQ  OutQ  Up/Down  State/PfxRcd
    2001:500::4   4  65530       42       65       0    0     0  00:30:50       1
    3ffe::cc00:2  4  65530       35       45       0    0     0  00:31:09       1
    
    Total number of neighbors 2
    

    rt4

    rt4{}show routing ipv6 bgp summary
    BGP router identifier 10.1.1.4, local ASN 65530
    1 BGP AS-PATH entries
    0 BGP community entries
    Neighbor      V     AS MsgRcvd  MsgSent  TblVer  InQ  OutQ  Up/Down  State/PfxRcd
    2001:500::3   4  65530      42       62       0    0     0  00:31:29       1
    3ffe::cc00:1  4  65530      38       43       0    0     0  00:31:47       1
    
    Total number of neighbors 2
    
  5. Check the BGP 4+ RIB:

    rt3

    rt3{}show routing ipv6 bgp
    BGP table version is 0, local router ID is 10.1.1.3
    Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
    Origin codes: i -IGP, e - EGP, ? - incomplete
    
    Network           Next Hop     Metric  LocPrf Weight Path
    * i2001:500::/64  2001:500::4       0  100         0 i
    * i               3ffe::cc00:2      0  100         0 i
    *> :: 0 32768 i
    
    Total number of prefixes 1
    

    rt4

    rt4{}show routing ipv6 bgp
    BGP table version is 0, local router ID is 10.1.1.4
    Status codes: s suppressed, d damped, h history, * valid, > best, i - internal
    Origin codes: i -IGP, e - EGP, ? - incomplete
    
    Network           Next Hop    Metric  LocPrf Weight Path
    * i2001:500::/64  2001:500::3      0  100         0 i
    * i               3ffe::cc00:1     0  100         0 i
    *>                ::               0          32768 i
    Total number of prefixes 1
    

    Note

    If you only run BGP 4+ (full IPv6 environnement), it is required to configure a bgp router-id manually.