Configure BGP for IBM Cloud Connections

Before you begin, ensure you have completed the steps outlined in Add an IBM Direct Link Connection to a Cloud Router.

Add BGP information to the Cloud Router connection

  1. After completing the steps above, return to the Cloud Routers page in the PacketFabric portal.

  2. Click the connection to open its side panel.

  3. Under BGP Sessions, click Create New Session.

    Screenshot of the Create New Session action

Complete the following fields and then click Submit.

BGP Settings

The ASN and IP addresses are completed on your behalf and should not be modified.

  • Header row
    • Field
    • Description
  • Row 1
    • Allow longer prefixes

    • This applies to the allowed incoming and outgoing prefixes that you list below.

      For example, say you list 172.16.2.0/24 as an allowed incoming prefix. You have three other cloud connections with the following outgoing prefixes:

      Connection A: 172.16.2.0/24
      Connection B: 172.16.0.0/16
      Connection C: 172.16.2.128/25

      If you do not select this option, only routes from Connection A are allowed.

      If you select this option, the routes from Connection A and Connection C are allowed.

BFD settings

Select Enable BFD to enable Bidirectional Forwarding Detection (BFD) for this connection.

When BFD is enabled, test packets are periodically sent to BGP peers. If a peer fails to reply after a specified interval and number of attempts, the BGP session shuts down.

On its own, BGP will take about 90 seconds to detect a failure and shut down. With BFD, you can detect failures significantly faster.

Interval
The interval (in milliseconds) at which to send test packets to peers. The default is 300 ms, and you can enter a value from 3 to 30000 ms.
Multiplier
The multiplier is the number of consecutive packets that can be lost before BFD considers a peer down and shuts down BGP. The default is 3, and you can enter a value from 2 to 16.
NAT settings

This option appears if you selected a NAT-capable on-ramp.

Prefixes to NAT
The prefixes from the cloud that you want to associate with the NAT pool.
NAT Pool Prefixes
All prefixes that are NATed on this connection will be translated to the pool prefix address.
If this connection uses a public IP address, then this field is autofilled with the PacketFabric router prefix with /32.
If this connection uses a private IP address, then manually enter a /32 prefix that is different than the router peer IPs you entered above.
Allowed prefixes to cloud

This is a list of addresses that you want to allow into your IBM Cloud VPC. These can be addresses from other cloud environments or from a different IBM Cloud VPC.

If you are using NAT, this is pre-populated with the PacketFabric router peer IP.

  • Row
    • Field
    • Description
  • Row
    • ASN prepend

    • Number of additional times to add the ASN to the BGP path, resulting in a higher path length.

      Routes with higher path length (a higher ASN prepend value) have a lower priority.

  • Row
    • MED

    • The multi-exit discriminator (MED) value.

      When the same route is advertised in multiple locations, those with a lower MED are preferred by the peer AS.

  • Row
    • Prefix/Mask
    • Enter an allowed IP address range in CIDR format. You can add up to 1000 prefixes.
Allowed prefixes from cloud

This is a list of addresses from within the IBM Cloud environment that you want to advertise to other clouds. This can include the VPC internal space and any routes you have created.

  • Row
    • Field
    • Description
  • Row
    • Local preference
    • When the same route is received in multiple locations, those with a higher local preference value are preferred by the PacketFabric Cloud Router.
  • Row
    • Prefix/Mask
    • Enter an allowed IP address range in CIDR format. You can add up to 1000 prefixes.