Configure BGP for VPN Connections

Before you begin, ensure you have completed the steps outlined in Add a VPN Connection to the Cloud Router.

Add BGP information to the Cloud Router connection

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

If you have not yet configured a BGP session, you will see the Configure BGP action from the Cloud Routers table:

Screenshot of the Configure BGP action

If you have configured the BGP session but wish to make changes, you can access the BGP settings from the BGP Sessions page or by clicking the connection to open its side panel.

From here, click Manage BGP or click the view icon under BGP Sessions:

Screenshot of the Configure BGP action

Complete the following fields:

BGP settings
  • Header row
    • Field
    • Description
  • Row 1
    • PacketFabric ASN
    • This is the ASN you specified when creating your PacketFabric Cloud Router. You cannot edit this field.
  • Row 1
    • ASN
    • This is the ASN for your on-premises environment. If you have one, you can use your public ASN. Otherwise, you can select a private ASN.
  • Row 1
    • PacketFabric Router Peer IP + Mask (CIDR notation)
    • Enter an IP prefix of your choice (the inside IP).
  • Row 1
    • Customer On-premises Router Peer IP + Mask (CIDR notation)
    • Enter an IP prefix of your choice.
  • Row 1
    • BGP Authentication Key
    • Optionally, you can include an MD5 authentication key.
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.

  • Row
    • Field
    • Description
  • Row
    • BFD 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.
  • Row
    • BFD 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.
Session settings

These settings apply to all the prefixes you list below.

You can also set these on per-prefix basis. Settings specified on the prefix level override the session-level setting for that particular prefix.

You can leave these fields empty to accept the default values.

  • Header row

    • Field
    • Description

  • Row 1

    • AS Prepend

    • Number of additional times to add the ASN to the BGP path, resulting in a higher path length. Allowed values are integers from 0 to 5.

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

  • Row 1

    • MED

    • The multi-exit discriminator (MED) value. Allowed values are integers from 0 to 4294967295.

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

  • Row 1

    • 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. Allowed values are integers from 0 to 4294967295.

  • Row 1

    • Allow longer prefixes

    • This applies to all the allowed incoming and outgoing prefixes that you list below. You can also specify this on a per-prefix basis.

      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. (Any IPs from 172.16.2.0/24 to 172.16.2.0/32 are allowed.)

  • Row 1

    • Network Address Translation

    • These options appear if you opted for NAT capability when creating the connection.

      If you do not see these options or they are greyed out, your connection is not NAT capable.

      Source NAT – Translate the source IP address. For example, you can translate a pool of private IP addresses to a public IP address in order to reach an external resource that only accepts public IPs.

      Destination NAT – Translate the destination IP address. For example, if you need to translate a public IP address to a private IP addresses in your network. This may be necessary if you plan to make the connection exportable via Quick Connect.

Allowed prefixes to customer premises

This is a list of addresses that you want to allow into your on-premises router. These can be addresses from other cloud environments or from a different router. You can add up to 1000 prefixes.

The values you set above under Session settings apply to all prefixes. However, you can override those settings on a per-prefix basis.

For example, if you enabled Allow longer prefixes above but want to specify an exact prefix, then you can override the Allow longer setting by selecting Match type > Exact next to that particular prefix.

  • Row
    • Field
    • Description
  • Row
    • Prefix/Mask
    • Enter an allowed IP address range in CIDR format.
  • Row
    • Match type
    • Allow or disallow longer prefixes for this row (see the description above).
  • Row

    • AS prepend

    • Number of additional times to add the ASN to the BGP path, resulting in a higher path length. Allowed values are integers from 0 to 5.

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

  • Row

    • MED

    • The multi-exit discriminator (MED) value. Allowed values are integers from 0 to 4294967295.

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

Allowed prefixes from customer premise

This is a list of addresses from within the on-premises environment that you want to advertise to other connections on the Cloud Router. You can add up to 1000 prefixes.

The values you set above under Session settings apply to all prefixes. However, you can override those settings on a per-prefix basis.

  • Row
    • Field
    • Description
  • Row
    • Prefix/Mask
    • Enter an allowed IP address range in CIDR format.
  • Row
    • Match type
    • Allow or disallow longer prefixes for this row (see the description above).
  • 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. Allowed values are integers from 0 to 4294967295.

Updated on 10 Mar 2023