Configure BGP

Perform the following task to configure BGP.
  1. Configure general virtual router configuration settings.
    See Virtual Routers for details.
  2. Enable BGP for the virtual router, assign a router ID, and assign the virtual router to an AS.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGP.
    3. Select Enable to enable BGP for this virtual router.
    4. Assign a Router ID to BGP for the virtual router, which is typically an IPv4 address to ensure the Router ID is unique.
    5. Assign the AS Number, the number of the AS to which the virtual router belongs, based on the router ID. Range is 1-4,294,967,295.
    6. Click OK.
  3. Configure general BGP configuration settings.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPGeneral.
    3. Select Reject Default Route to ignore any default routes that are advertised by BGP peers.
    4. Select Install Route to install BGP routes in the global routing table.
    5. Select Aggregate MED to enable route aggregation even when routes have different Multi-Exit Discriminator (MED) values.
    6. Specify the Default Local Preference that can be used to determine preferences among different paths.
    7. Select the AS Format for interoperability purposes:
      • 2 Byte (default value)
      • 4 Byte
    8. Enable or disable each of the following settings for Path Selection:
      • Always Compare MED—Enable this comparison to choose paths from neighbors in different autonomous systems.
      • Deterministic MED Comparison—Enable this comparison to choose between routes that are advertised by IBGP peers (BGP peers in the same autonomous system).
    9. For Auth Profiles, Add an authentication profile:
      • Profile Name—Enter a name to identify the profile.
      • Secret/Confirm Secret—Enter and confirm a passphrase for BGP peer communications. The Secret is used as a key in MD5 authentication.
    10. Click OK.
    11. Click OK.
  4. (Optional) Configure BGP settings.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPAdvanced.
    3. Select ECMP Multiple AS Support if you configured ECMP and you want to run ECMP over multiple BGP autonomous systems.
    4. Select Enforce First AS for EBGP to cause the firewall to drop an incoming Update packet from an eBGP peer that doesn’t list the eBGP peer’s own AS number as the first AS number in the AS_PATH attribute. Default is enabled.
    5. Select Graceful Restart and configure the following timers:
      • Stale Route Time (sec)—Specifies the length of time in seconds that a route can stay in the stale state (range is 1-3,600; default is 120).
      • Local Restart Time (sec)—Specifies the length of time in seconds that the local device waits to restart. This value is advertised to peers (range is 1-3,600; default is 120).
      • Max Peer Restart Time (sec)—Specifies the maximum length of time in seconds that the local device accepts as a grave period restart time for peer devices (range is 1-3,600; default is 120).
    6. For Reflector Cluster ID, specify an IPv4 identifier to represent the reflector cluster.
    7. For Confederation Member AS, specify the autonomous system number identifier (also called a sub-AS number), which is visible only within the BGP confederation. For more information, see BGP Confederations.
    8. Add the following information for each Dampening Profile that you want to configure, select Enable, and click OK:
      • Profile Name—Enter a name to identify the profile.
      • Cutoff—Specify a route withdrawal threshold above which a route advertisement is suppressed (range is 0.0-1,000.0; default is 1.25).
      • Reuse—Specify a route withdrawal threshold below which a suppressed route is used again (range is 0.0-1,000.0; default is 5).
      • Max Hold Time (sec)—Specify the maximum length of time in seconds that a route can be suppressed, regardless of how unstable it has been (range is 0-3,600 seconds; default is 900).
      • Decay Half Life Reachable (sec)—Specify the length of time in seconds after which a route’s stability metric is halved if the route is considered reachable (range is 0-3,600 seconds; default is 300).
      • Decay Half Life Unreachable (sec)—Specify the length of time in seconds after which a route’s stability metric is halved if the route is considered unreachable (range is 0-3,600; default is 300).
    9. Click OK.
    10. Click OK.
  5. Configure a BGP peer group.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPPeer Group and Add a Name for the peer group and select Enable.
    3. Select Aggregated Confed AS Path to include a path to the configured aggregated confederation AS.
    4. Select Soft Reset with Stored Info to perform a soft reset of the firewall after updating the peer settings.
    5. Select the Type of peer group:
      • IBGPExport Next Hop: Select Original or Use self
      • EBGP ConfedExport Next Hop: Select Original or Use self
      • EBGP ConfedExport Next Hop: Select Original or Use self
      • EBGPImport Next Hop: Select Original or Use self, Export Next Hop: Specify Resolve or Use self. Select Remove Private AS if you want to force BGP to remove private AS numbers from the AS_PATH attribute in Updates that the firewall sends to a peer in another AS.
    6. Click OK.
  6. Configure a BGP peer that belongs to the peer group and specify its addressing.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPPeer Group and select the peer group you created.
    3. For Peer, Add a peer by Name.
    4. Select Enable to activate the peer.
    5. Enter the Peer AS to which the peer belongs.
    6. Select Addressing.
    7. For Local Address, select the Interface for which you are configuring BGP. If the interface has more than one IP address, enter the IP address for that interface to be the BGP peer.
    8. For Peer Address, select either IP and enter the IP address or select or create an address object, or select FQDN and enter the FQDN or address object that is type FQDN.
      The firewall uses only one IP address (from each IPv4 or IPv6 family type) from the DNS resolution of the FQDN. If the DNS resolution returns more than one address, the firewall uses the preferred IP address that matches the IP family type (IPv4 or IPv6) configured for the BGP peer. The preferred IP address is the first address the DNS server returns in its initial response. The firewall retains this address as preferred as long as the address appears in subsequent responses; regardless of its order.
    9. Click OK.
  7. Configure connection settings for the BGP peer.
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPPeer Group and select the peer group you created.
    3. Select the Peer you configured.
    4. Select Connection Options.
    5. Select an Auth Profile for the peer.
    6. Set a Keep Alive Interval (sec), the interval (in seconds) after which routes from the peer are suppressed according to the Hold Time setting (range is 0-1,200; default is 30).
    7. Set Multi Hop, the time-to-live (TTL) value in the IP header (range is 1-255; default is 0. The default value of 0 means 2 for eBGP prior to PAN-OS 8.0.2, and it means 1 beginning with PAN-OS 8.0.2. The default value of 0 means 255 for iBGP).
    8. Set Open Delay Time (sec), the delay in seconds between a TCP handshake and the firewall sending the first BGP Open message to establish a BGP connection (range is 0-240; default is 0).
    9. Set Hold Time (sec), the length of time in seconds that may elapse between successive Keepalive or Update messages from the peer before the peer connection is closed (range is 3-3,600; default is 90).
    10. Set Idle Hold Time (sec), the length of time to wait (in seconds) before retrying to connect to the peer (range is 1-3,600; default is 15).
    11. Set Min Route Advertisement Interval (sec), the minimum number of seconds between two successive Update messages that a BGP speaker (the firewall) sends to a BGP peer that advertise routes and/or withdrawal of routes (range is 1 to 600; default is 30).
    12. For Incoming Connections, enter a Remote Port and select Allow to allow incoming traffic to this port.
    13. For Outgoing Connections, enter a Local Port and select Allow to allow outgoing traffic from this port.
    14. Click OK.
  8. Configure the BGP peer with settings for route reflector client, peering type, maximum prefixes, and Bidirectional Forwarding Detection (BFD).
    1. Select NetworkVirtual Routers and select a virtual router.
    2. Select BGPPeer Group and select the peer group you created.
    3. Select the Peer you configured.
    4. Select Advanced.
    5. For Reflector Client, select one of the following:
      • non-client—Peer is not a route reflector client (default).
      • client—Peer is a route reflector client.
      • meshed-client
    6. For Peering Type, select one of the following:
      • Bilateral—The two BGP peers establish a peer connection.
      • Unspecified— (default).
    7. For Max Prefixes, enter the maximum number of supported IP prefixes (range is 1-100,000) or select unlimited.
    8. To enable BFD for the peer (and thereby override the BFD setting for BGP, as long as BFD is not disabled for BGP at the virtual router level), select one of the following:
      • default—Peer uses only default BFD settings.
      • Inherit-vr-global-setting (default)—Peer inherits the BFD profile that you selected globally for BGP for the virtual router.
      • A BFD profile you configured—See Create a BFD profile.
        Selecting Disable BFD disables BFD for the BGP peer.
    9. Click OK.
  9. Configure Import and Export rules.
    The import/export rules are used to import/export routes from/to other routers. For example, importing the default route from your Internet Service Provider.
    1. Select the Import tab and Add a name in the Rules field and select Enable.
    2. Add the Peer Group from which the routes will be imported.
    3. Click the Match tab and define the options used to filter routing information. You can also define the Multi-Exit Discriminator (MED) value and a next hop value to routers or subnets for route filtering. The MED option is an external metric that lets neighbors know about the preferred path into an AS. A lower value is preferred over a higher value.
    4. Click the Action tab and define the action that should occur (allow/deny) based on the filtering options defined in the Match tab. If Deny is selected, no further options need to be defined. If the Allow action is selected, define the other attributes.
    5. Click the Export tab and define export attributes, which are similar to the Import settings, but are used to control route information that is exported from the firewall to neighbors.
    6. Click OK.
  10. Configure conditional advertising, which allows you to control what route to advertise in the event that a different route is not available in the local BGP routing table (LocRIB), indicating a peering or reachability failure.
    This is useful in cases where you want to try to force routes to one AS over another, for example if you have links to the Internet through multiple ISPs and you want traffic to be routed to one provider instead of the other unless there is a loss of connectivity to the preferred provider.
    1. Select the Conditional Adv tab, Add a name in the Policy field.
    2. Select Enable.
    3. Add in the Used By section the peer group(s) that will use the conditional advertisement policy.
    4. Select the Non Exist Filter tab and define the network prefix(es) of the preferred route. This specifies the route that you want to advertise, if it is available in the local BGP routing table. If a prefix is going to be advertised and matches a Non Exist filter, the advertisement will be suppressed.
    5. Select the Advertise Filters tab and define the prefix(es) of the route in the Local-RIB routing table that should be advertised in the event that the route in the non-exist filter is not available in the local routing table. If a prefix is going to be advertised and does not match a Non Exist filter, the advertisement will occur.
  11. Configure aggregate options to summarize routes in the BGP configuration.
    BGP route aggregation is used to control how BGP aggregates addresses. Each entry in the table results in one aggregate address being created. This will result in an aggregate entry in the routing table when at least one or more specific route matching the address specified is learned.
    1. Select the Aggregate tab, and Add a name for the aggregate address.
    2. In the Prefix field, enter the network prefix that will be the primary prefix for the aggregated prefixes.
    3. Select the Suppress Filters tab and define the attributes that will cause the matched routes to be suppressed.
    4. Select the Advertise Filters tab and define the attributes that will cause the matched routes to always be advertised to peers.
  12. Configure redistribution rules.
    This rule is used to redistribute host routes and unknown routes that are not on the local RIB to the peers routers.
    1. Select the Redist Rules tab and click Add.
    2. In the Name field, enter an IP subnet or select a redistribution profile. You can also configure a new redistribution profile if needed.
    3. Enable the rule.
    4. In the Metric field, enter the route metric that will be used for the rule.
    5. In the Set Origin list, select incomplete, igp, or egp.
    6. (Optional) Set MED, local preference, AS path limit and community values.

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