Configure BGP on Switches via Mist

Understand the benefits of Border Gateway Protocol (BGP) and follow these steps to configure a BGP group on your switch.

BGP is an exterior gateway protocol (EGP) that is used to exchange routing information among routers or layer 3 switches in different autonomous systems (AS). The routing information includes the complete route to each destination. BGP uses this information to maintain a database of network reachability information, which it exchanges with other BGP systems. BGP uses the network reachability information to construct a graph of AS connectivity, which enables BGP to prevent routing loops and enforce policy decisions at the AS level.

At a high level BGP configuration includes a BGP group, BGP neighbors, and a routing policy to advertise the BGP routes.

For BGP configuration examples and CLI steps, see BGP Configuration Overview.

Before you configure BGP, ensure that you have configured the network interfaces (L3 interfaces). You can configure L3 interface from the Port Configuration tile on the switch details page (Switches > Switch Name). In this configuration, you need to specify the ports, interface type (L3), IP address, and subnet mask (see the image below).

To configure BGP on a switch via Mist:

1. In the Mist portal, click Switches to go to the list of switches.
2. From the switch list, click the switch on which you want to configure BGP. The switch details page is displayed.
3. In the BGP section on the switch details page, select the Enabled check box.
4. Click Add BGP Group.
   

   The Add BGP Group window is displayed.

5. Configure the BGP Group settings as described below:

   Field	Description
   Name	Specify a name for the BGP group.
   Type	Select one of the following BGP type: Internal: When two BGP-enabled devices are in the same autonomous system (AS), the BGP session is called an internal BGP session, or IBGP session. IBGP routes traffic within an autonomous system. External: External BGP routes traffic between devices that belong to different autonomous systems.
   Network (VLAN)	Select a network. The BGP group will be added to the VRF that this network is a part of. If the VRF has more than one network, any one of them can be selected.
   BFD Interval (in milliseconds)	Specify the Bidirectional Forwarding Detection (BFD) interval in milliseconds. BFD protocol is a simple hello mechanism that detects failures in a network. Hello packets are sent at a specified, regular interval. A neighbor failure is detected when the routing device stops receiving a reply after a specified interval.
   Local AS	Specify the local autonomous system (AS) number. For more information, see Understanding the BGP Local AS Attribute.
   Hold Time	Specify the hold-time value to use when negotiating a connection with the peer. The hold-time value is advertised in open packets and indicates to the peer the length of time that it should consider the sender valid. If the peer does not receive a keepalive, update, or notification message within the specified hold time, the BGP connection to the peer is closed and routing devices through that peer become unavailable. The device calculates the BGP keepalive interval as one-third of the configured hold time. For instance, if you set the hold time to 90 seconds, the keepalive interval will be set to 30 seconds.
   Authentication Key	Configure an MD5 authentication key (password). Neighboring routing devices use the same password to verify the authenticity of BGP packets sent from this system.
   Export	Select a routing policy to determine which routes are advertised to BGP peers. An export policy is applied to outbound routes that are visible in the output of the show route advertising-protocol bgp neighbor-address command. If you don’t have a policy available, click Create Policy button on the drop-down menu to create a new one. For more information, see Configure Routing Policies on Switches via Mist.
   Import	Select a routing policy to determine which routes are accepted from BGP peers and added to the local routing table. An import policy is applied to inbound routes that are visible in the output of the show route receive-protocol bgp neighbor-address command. If you don’t have a policy available, click Create Policy button on the drop-down menu to create a new one. For more information, see Configure Routing Policies on Switches via Mist.

6. Click Add Neighbor.
   

   The Add Neighbor (IPv4 / IPv6) window is displayed.

7. Configure the neighbor information as described below:

   Field	Description
   IP Address	Specify the IP address of the remote BGP peer.
   Neighbor AS	Specify the AS number of the remote BGP peer.
   Hold Time	Specify the hold-time value to use when negotiating a connection with the peer.
   Export	Select a routing policy to determine which routes are advertised to the BGP peer.
   Import	Select a routing policy to determine which routes are accepted from the BGP peer and added to the local routing table.

8. After configuring the neighbor information, click the check mark on the upper right of the Add Neighbor window.
9. Click the Add button on the lower left of the Add BGP window.
10. To save the configuration, click Save on the upper right of the switch details page.