Configuring Dynamic Routing with OSPF or BGP

You can configure the BGP per segment at the Profile level as well as at the Edge level. This section provides steps on how to configure BGP with Underlay Neighbors.

1. In the SD-WAN service of the Enterprise Portal, select Configure.
2. Select Profiles to display the list of available profiles.
3. Select a Profile from the list of available Profiles or Add a Profile if necessary.
4. Go to the Routing & NAT section and select the arrow next to BGP to expand.
5. In the BGP area, enabled BGP by selecting On.

   

6. In the BGP area, enter the local Autonomous System Number (ASN) number in the appropriate text field.
7. Configure BGP Settings:

   Table 4. BGP Settings Option Descriptions

   Option	Description
   Router ID	Enter the global BGP router ID. If you do not specify any value, the ID assigns automatically. If you configured a loopback Interface for the Edge, the IP address of the loopback Interface assigns as the router ID.
   Keep Alive	Enter the keep alive timer in seconds, the duration between the keep alive messages sent to the peer. Use a range from 0 to 65535 seconds with a default value of 60 seconds.
   Hold Timer	Enter the hold timer in seconds. When the keep alive message is not received for the specified time, the peer is considered as down. The range is from 0 to 65535 seconds. The default value is 180 seconds.
   Uplink Community	Enter the community string to be treated as uplink routes. Uplink refers to link connected to the Provider Edge(PE). Inbound routes towards the Edge matching the specified community value will be treated as Uplink routes. The Hub/Edge is not considered as the owner for these routes. Enter the value in number format ranging from 1 to 4294967295 or in AA:NN format.
   Enable Graceful Restart	Please note when selecting this check box:The local router does not support forwarding during the routing plane restart. This feature supports preserving forwarding and routing in case of peer restart.

8. Select +Add in the Filter List area to create one or more filters. Apply the filters to a neighbor to deny or change the attributes of the route. The same filter can be used for multiple neighbors.

   

9. Add the Filter rules.

   Table 5. Filter Rules Option Descriptions

   Option	Description
   Filter Name	Enter a descriptive name for the BGP filter.
   Match Type and Value	Choose the type of the routes to be matched with the filter: Prefix for IPv4 or IPv6: Choose to match with a prefix for IPv4 or IPv6 address and enter the corresponding prefix IP address in the Value field. Community: Choose to match with a community and enter the community string in the Value field.
   Exact Match	The filter action is performed only when the Prosecutes match exactly with the specified prefix or community string. By default, this option is enabled.
   Action Type	Choose the action to be performed when Thebes routes match with the specified prefix or the community string. You can either permit or deny the traffic.
   Action Set	When the BGP routes match the specified criteria, you can set to route the traffic to a network based on the attributes of the path. Select one of the following options from the drop-down list: None- The attributes of the matching routes remain the same. Local Preference- The matching traffic routs to the path with the specified local preference. Community- The matching routes filter by the specified community string. You can also select Community Additive to enable the additive option, which appends the community value to existing communities. Metric- The matching traffic routs to the path with the specified metric value.

10. Select plus (+) to add more matching rules for the filter. Repeat the procedure to create more BGP filters.
    The configured Filters display in the Filter List.

    Note: The maximum number of supported BGPv4 Match/Set rules is 512 (256 inbound, 256 outbound). Exceeding 512 total Match/Set rules is not supported and may cause performance issues, resulting in disruptions to the enterprise network.
11. Navigate to Neighbors and select +Add.

    

12. Configure the following settings for the IPv4 addressing type:

    Table 6. IPv4 Addressing Type Option Descriptions

    Option	Description
    Neighbor IP	Enter IP address of the BGP neighbor.
    ASN	Enter the ASN of the neighbor.
    Inbound Filter	Select an Inbound Filter from the list.
    Outbound Filter	Select an Outbound Filter from the list.

    Note: When overriding and configuring BGP neighbors at the Edge level, any Profile-level filters associated with the neighbors will be removed when you switch the Edge from one profile to another. So at the Edge level, you must make sure to reassociate the filters with the BGP neighbors after switching the Edge profile.

    Table 7. Additional Option Descriptions

    Option	Description
    Max-hop	Enter the number of maximum hops to enable multi-hop for the BGP peers. The range is from 1 to 255 and the default value is 1. Note: This field is available only for eBGP neighbors, when the local ASN and the neighboring ASN are different. With iBGP, when both ASNs are the same, multi-hop is inherent by default and this field is not configurable.
    Local IP	Local IP address is the equivalent of a loopback IP address. Enter an IP address that the BGP neighborships can use as the source IP address forth outgoing packets. If you do not enter any value, the IP address of the physical Interface is used as the source IP address. Note: For eBGP, this field is available only when Max- hop count is more than 1. For iBGP, it is always available as iBGP is inherently multi-hop.
    Uplink	Used to flag the neighbor type to Uplink. Select this flag option if it is used as the WAN overlay towards MPLS. It will be used as the flag to determine whether the site will become a transit site (e.g. SD-WAN Hub), by propagating routes leant over a SD-WAN overlay to a WAN link toward MPLS. If you need to make it a transit site, also check "Overlay Prefix Over Uplink" in the Advanced Settings area.
    Allow AS	Select the check box to allow the BGP routes to be received and processed even if the Edge detects its own ASN in the AS-Path.
    Default Route	The Default Route adds a network statement in the BGP configuration to advertise the default route to the neighbor.
    Enable BFD	Enables subscription to existing BFD session for the BGP neighbor.
    Keep Alive	Enter the keep alive timer in seconds, which is the duration between the keep alive messages that are sent to the peer. The range is from 0 to 65535 seconds. The default value is 60 seconds.
    Hold Timer	Enter the hold timer in seconds. When the keep alive message is not received for the specified time, the peer is considered as down. The range is from 0 to 65535 seconds. The default value is 180 seconds.
    Connect	Enter the time interval to try a new TCP connection with the peer if it detects the TCP session is not passive. The default value is 120 seconds.
    MD5 Auth	Select the check box to enable BGP MD5 authentication. This option is used in a legacy network or federal network, and it is common that BGP MD5 is used as a security guard for BGP peering.
    MD5 Password	Enter a password for MD5 authentication. Note: Starting from the 4.5 release, the use of the special character < in the password is no longer supported. In cases where users have already used < in their passwords in previous releases, they must remove it to save any changes on the page.

13. Select (+) to add more BGP neighbors.
    Note:

    Over Multi-hop BGP, the system might learn routes that require recursive lookup. These routes have a next-hop IP which is not in a connected subnet, and do not have a valid exit Interface. In this case, the routes must have the next-hop IP resolved using another route in the routing table that has an exit Interface. When there is traffic for destination that needs these routes to be looked up, routes requiring recursive lookup resolve to a connected Next Hop IP address and Interface. Until the recursive resolution happens, the recursive routes point to an intermediate Interface. For more information about Multi-hop BGP Routes, see the "Remote Diagnostic Tests on Edges" section in the VeloCloud SD-WAN Troubleshooting Guide.

14. Navigate to Advanced Settings and select the down arrow to open the Advanced Settings section.

    

15. Configure the following advanced settings and apply them globally to all the BGP neighbors with IPv4 addresses.

    Table 8. Advanced Settings Option Descriptions

    Option	Description
    Overlay	Select the check box to redistribute the prefixes learned from the overlay. For example, when a Spoke is connected to primary and secondary Hub or Hub Cluster, the Spoke's subnets are redistributed by primary and secondary Hub or Hub Cluster to their neighbor with metric (MED) 33 and 34 respectively. You must configure "bgp always-compare-med" in the neighbor router for symmetric routing.
    Turn off AS-Path carry over	By default, this should be left unchecked. Select the check box to deactivate AS-PATH Carry Over. In certain topologies, deactivating AS-PATH Carry Over will influence the outbound AS-PATH to make the L3 routers prefer a path towards an Edge or a Hub. Warning: When the AS-PATH Carry Over is deactivated, tune your network to avoid routing loops.
    Connected Routes	Select the check box to redistribute all the connected Interface subnets.
    OSPF	Select the check box to enable OSPF redistribute into BGP.
    Set Metric	When you enable OSPF, enter the BGP metric for the redistributed OSPF routes. The default value is 20.
    Default Route	Select the check box to redistribute the default route only when Edge learns the BGP routes through overlay or underlay. When you select the Default Route option, the Advertise option is available as Conditional.
    Overlay Prefixes over Uplink	Select the check box to propagate routes learned from overlay to the neighbor with uplink flag.
    Networks	Enter the network address in IPv4 format that BGP will be advertising to the peers. Select the plus + icon to add more network addresses.

    When you enable the Default Route option, the BGP routes advertise based on the Default Route selection globally and per BGP neighbor.

    Table 9. Default Route Selections

    Default Route Selection
    Global	Per BGP Neighbor	Advertising Options
    Yes	Yes	The per BGP neighbor configuration overrides the global configuration and hence default route is always advertised to the BGP peer.
    Yes	No	BGP redistributes the default route to its neighbor only when the Edge learns an explicit default route through the overlay or underlay network.
    No	Yes	Default route is always advertised to the BGP peer.
    No	No	The default route is not advertised to the BGP peer.

16. Select the IPv6 tab to configure the BGP settings for IPv6 addresses. Enter a valid IPv6 address of the BGP neighbor in the Neighbor IP field. The BGP peer for IPv6 supports the following address format:
    • Global unicast address (2001:CAFE:0:2:1)
    • Unique Local address (FD00:1234:BEFF:ACE:E0A4)
17. Configure the other settings as required.
    Note: The Local IP address configuration is not available for IPv6 address type.
18. Select Advanced to configure the following advanced settings, which globally apply to all the BGP neighbors with IPv6 addresses.

    Table 10. Advanced Option Descriptions

    Option	Description
    Connected Routes	Select to redistribute all the connected Interface subnets.
    Default Route	Select to redistribute the default route only when Edge learns the BGP routes through overlay or underlay. When you select the Default Route option, the Advertise option is available as Conditional.
    Networks	Enter the network address in IPv6 format that BGP advertises to the peers. Select (+) to add more network addresses.

    Route Summarization

    The Route Summarization feature is available in the 5.2 release, for an overview and use case of this functionality, see Route Summarization.

19. Select +Add in the Route Summarization area and add a new to the Route Summarization area.

    

20. Under the Subnet column, enter the network range that you want to summarize in the A.B.C.D/M format and the IP subnet.
21. Under the AS Set column, select Yes if applicable.
22. Under the Summary Only column, select Yes to send only the summarized route.
23. Add additional routes, if necessary, by selecting +Add. To Clone or Delete a route summarization, use the appropriate buttons, located next to +Add.
    The BGP Settings section displays the BGP configuration settings.
24. Select Save Changes when complete to save the configuration.
    Note: When you configure BGP settings for a profile, the configuration settings are automatically applied to the SD-WAN Edges that are associated with the profile.

    You can also configure BGP for Non SD-WAN Destination Neighbors in an Edge. For more information, see Configure BGP Over IPsec from Edge to Non SD-WAN Neighbors.

You can override the inherited Profile settings at the Edge level when configuring BGP from the Edge to Underlay Neighbors.

1. In the SD-WAN service of the Enterprise portal, select Configure > Edges . The Edges page displays the configured Edges.
2. Select on an Edge or select View in the Device column of the Edge.
3. Go to the Routing & NAT section and select the arrow next to BGP to expand.
4. The BGP Settings configured for the associated Profile are displayed. If required, you can select Override and modify the BGP Settings.
   Note: Overriding and configuring BGP neighbors at the Edge level removes any Profile-level filters associated with the neighbors when you switch the Edge from one profile to another. At the Edge level, you must make sure to reassociate the filters with the BGP neighbors after switching the Edge profile.
5. In addition to the BGP Settings configured for a Profile, you can select an Edge Interface configured in the segment as the source Interface for BGP. For the IPv4 address type, you can select only the Loopback Interface as Source Interface and for the IPv6 address type, you can select any Edge Interface as the Source Interface. This field becomes available:
   • Only when you choose to override the BGP Settings at the Edge level.
   • For eBGP, only when Max-hop count is more than 1. For iBGP, it is always available as iBGP is inherently multi-hop.

   Important:

   • You cannot select an Edge Interface if you have already configured a local IP address in the Local IP field.
   • You cannot configure a local IP address if you have selected an Edge Interface in the Source Interface list.
6. Select Save Changes to save the modified configuration.

Only eBGP is supported with BGP over IPsec.

1. Go to Configure > Network Services and then under Non SD-WAN Destinations, expand Non SD-WAN Destinations via Gateway.
   Note: The New NSD via Gateway option appears only when there are no items in the table. Follow Steps 2 and 3 to create a new Non SD-WAN Destination.

   

2. Select +New to create a new Non SD-WAN Destination.

   

3. In Non SD-WAN Destinations via Gateway, configure the following fields:

   Table 16. Non SD-WAN Destinations via Gateway Option Descriptions

   Option	Description
   Name	Enter a name for the Non SD-WAN Destination in the text box.
   Type	Select an IPsec tunnel type from the menu.
   Tunnel Mode	Active/ Hot-Standby mode supports to set up a maximum of 2 tunnel endpoints or Gateways.
   	Active/Active mode supports to set up a maximum of 4 tunnel endpoints or Gateways. All Active tunnels can send and receive traffic through ECMP.
   VPN Gateway 1	Enter a valid IP address.
   VPN Gateway 2	Enter an optional valid IP address.

    

4. Select Create to add the new destination.

   

5. In the Non SD-WAN Destination via Gateway area, slide the grey bar to the far right to the BGP column.

   Select the Edit link under the BGP column.

   If the Edit link does not display under the BGP column, see the section Configure a Tunnel Between a Branch and a Non SD-WAN Destinations via Edge to enable an Edge to Non SD-WAN via Gateway.

   After selecting the Edit link under the BGP column, the Edit BGP dialog displays.

6. Toggle the BGP Activated radio button to the right to turn it green.
7. Select +Add to create one or more filters. These filters are applied to the neighbor to deny or change the attributes of the route. The same filter can be used for multiple neighbors.
8. Configure the options in the Filter List area:

   Table 17. Filter List Option Descriptions

   Option	Description
   Filter Name	Enter a descriptive name for the BGP filter.
   Match Type and Value	Choose the type of the routes to match with the filter: Prefix for IPv4 or IPv6- Choose to match with a prefix for IPv4 or IPv6 address and enter the corresponding prefix IP address in the Value field. Community- Select to match with a community and enter the community string in the Value field.
   Exact Match	The filter action is performed only when the BGP routes match exactly with the specified prefix or community string. By default, this option is enabled.
   Action Type	Choose the action to be performed when the BGP routes match with the specified prefix or the community string. You can either permit or deny the traffic.
   Action Set	When the BGP routes match the specified criteria, you can set to route the traffic to a network based on the attributes of the path. Select one of the following options from the drop-down list: None- The attributes of the matching routes remain the same. Local Preference- The matching traffic is routed to the path with the specified local preference. Community- The matching routes are filtered by the specified community string. You can also select Community Additive to enable the additive option, which appends the community value to existing communities. Metric- The matching traffic is routed to the path with the specified metric value. AS-Path-Prepend- Allows pre-pending multiple entries of Autonomous System (AS) to a BGP route.

9. Select (+) to add more matching rules for the filter. Repeat the procedure to create more filters.

   

   

   Note: These BGP neighbors are assigned to their respective tunnels exclusively for neighborship establishment and subsequent control exchanges, ensuring these communication occurs solely over the designated tunnels.
10. In the BGP Editor window, configure the BGP settings for the Primary and Secondary Gateways.
    Note: The Secondary Gateway option is available only if you have configured a secondary Gateway for the corresponding Non SD-WAN Destination.

    Note: For a customer deployment where a Non VeloCloud SD-WAN Destination (NSD) via Gateway is configured to use redundant tunnels, if the Primary and Secondary Gateways advertise a prefix with an equal AS path to the Primary and Secondary NSD tunnels, the Primary NSD tunnel will prefer a redundant Gateway path over the Primary Gateway. The impact of the Primary NSD over Gateway tunnel preferring the redundant Gateway path over the Primary Gateway is experienced only for return traffic to the Gateway from the NSD. If you do not want your BGP router to prefer the redundant Gateway, the workaround is to configure AS-PATH prepend and set the metric filter to a higher (3 or more) metric for the advertised prefix in the redundant Gateway. Doing this ensures the NSDs primary tunnel chooses the Primary Gateway for return traffic.
11. In the Primary Cloud Gateway section, enter the local ASN and the Router ID.
12. Scroll down to the Neighbors area and select +Add.
13. Configure the following settings in the Neighbors area:

    

    Table 18. BGP Neighbors Option Descriptions

    Option	Description
    Local ASN	Enter the local Autonomous System Number (ASN)
    Router ID	Enter the BGP Router ID.
    Neighbor IP	Enter the IP address of the NSD neighbor.
    ASN	Enter the ASN for the NSD neighbor.
    Inbound Filter	Select an Inbound filter from the list.
    Outbound Filter	Select an Outbound filter from the list.
    Additional Options – Select View All to configure the following additional settings:
    Local IP	Local IP is mandatory for configuring Non SD-WAN Neighbors. Local IP address is the equivalent of a loopback IP address. Enter an IP address that the BGP neighborships can use as the source IP address for the outgoing packets.
    Max-hop	Enter the number of maximum hops to enable multi-hop for the BGP peers. For the 5.1 release and later, the range is from 2 to 255 and the default value is 2. Note: When upgrading to the 5.1 release, any max-hop value of 1 automatically updates to a max-hop value of 2. Note: This field is available only for eBGP neighbors, when the local ASN and the neighboring ASN are different. With iBGP, when both ASNs are the same, multi-hop is deactivated by default and this field is not configurable.
    Allow AS	Select the check box to allow the BGP routes to be received and processed even if the Edge detects its own ASN in the AS-Path.
    Default Route	The Default Route adds a network statement in the BGP configuration to advertise the default route to the neighbor.
    Enable BFD	Enables subscription to existing BFD session for the BGP neighbor. Note: Single-hop BFD session is not supported for BGP over IPSec with NSD Neighbors. However, multi-hop BFD is supported. Local IP is mandatory for NSD-BGP sessions on the SD-WAN Edge. The SD-WAN Edge handles only the connected Interface IPs as a single-hop BFD.
    Keep Alive	Enter the keep alive timer in seconds, which is the duration between the keep alive messages that are sent to the peer. The range is from 0 to 65535 seconds. The default value is 60 seconds.
    Hold Timer	Enter the hold timer in seconds. When the keep alive message is not received for the specified time, the peer is considered as down. The range is from 0 to 65535 seconds. The default value is 180 seconds.
    Connect	Enter the time interval to try a new TCP connection with the peer if it detects the TCP session is not passive. The default value is 120 seconds.
    MD5 Auth	Select the check box to enable BGP MD5 authentication. This option is used in a legacy network or federal network, and it is common that BGP MD5 is used as a security guard for BGP peering.
    MD5 Password	Enter a password for MD5 authentication. Note: Starting from the 4.5 release, the use of the special character < in the password is no longer supported. In cases where users have already used < in their passwords in previous releases, they must remove it to save any changes on the page.

    The configured Neighbors are displayed in the Neighbors area.

    

    Note: Over Multi-hop BGP, the system might learn routes that require recursive lookup. These routes have a next-hop IP which is not in a connected subnet, and do not have a valid exit Interface. In this case, the routes must have the next-hop IP resolved using another route in the routing table that has an exit Interface. When there is traffic for a destination that needs these routes to be looked up, routes requiring recursive lookup will get resolved to a connected Next Hop IP address and Interface. Until the recursive resolution happens, the recursive routes point to an intermediate Interface. For more information about Multi-hop BGP Routes, see the "Remote Diagnostic Tests on Edges" section in the VeloCloud SD-WAN Troubleshooting Guide.
14. Select Save Changes.

    Route Summarization

    The Route Summarization feature is available in the 5.2 release, for an overview and use case of this functionality, see Route Summarization. For configuration details, follow the steps below.

15. Scroll down to the Route Summarization area.
16. Select +Add in the Route Summarization to add a new row to the Route Summarization table. Configure route summarization, as described in the table below.

    Table 19. Route Summarization Option Descriptions

    Option	Description
    Filter Name	Enter a descriptive name for the BGP filter.
    Subnet	Enter the IP subnet.
    AS Set	Generate AS set path information from the summarized routes (while advertising the summary route to the peer). Under the AS Set column, select Yes if applicable.
    Summary Only	Select Yes to allow only the summarized route to be sent.

     

17. Add additional routes, if necessary, by selecting +Add. To Clone or Delete a route summarization, use the appropriate buttons, located next to +Add.

    The BGP Settings section displays the BGP configuration settings.

    

18. Select Save Changes when complete to save the configuration.
    Note:

    • Only for Gateways running version 6.0 or later have an option to configure up to 4 tunnels based on VPN type. In addition, those tunnels destined to be a Non SD-WAN gateway can operate in either AA or A-HS mode to achieve load sharing/bearing preferences of the user.
    • For gateways running version less than 6.0, all active-active configurations are interpreted as active-hotstandby with tunnel 1 being active and tunnel 2 being hot-standby.

You can run Remote Diagnostics tests to view the logs of the BGP sessions and use the log information for troubleshooting purposes.

1. In the SD-WAN service of the Enterprise Portal, select Diagnostics > Remote Diagnostics .
2. The Remote Diagnostics page displays all the active Edges.
3. Select the Edge that you want to troubleshoot. The Edge enters live mode and displays all the possible Remote Diagnostics tests than you can run on the Edge.
4. For troubleshooting BGP sessions, scroll to the following sections and run the tests:
   • Troubleshoot BGP- List BGP Redistributed Routes – Run this test to view routes redistributed to BGP neighbors.
   • Troubleshoot BGP- List BGP Routes – Run this test to view the BGP routes from neighbors. You can enter IPv4 or IPv6 prefix to view specific BGP routes or leave the prefix empty to view all the BGP routes.
   • Troubleshoot BGP- List Routes per Prefix – Run this test to view all the Overlay and Underlay routes for a specific IPv4 or IPv6 prefix and the related details
   • Troubleshoot BGP- Show BGP Neighbor Advertised Routes – Run this test to view the BGP routes advertised to a neighbor.
   • Troubleshoot BGP- Show BGP Neighbor Learned Routes – Run this test to view all the accepted BGP routes learned from a neighbor after filters.
   • Troubleshoot BGP- Show BGP Neighbor Received Routes – Run this test to view all the BGP routes learned from a neighbor before filters.
   • Troubleshoot BGP- Show BGP Neighbor details – Run this test to view the details of BGP neighbor.
   • Troubleshoot BGP- Show BGP Routes per Prefix – Run this test to view all the BGP routes and their attributes for the specified prefix.
   • Troubleshoot BGP- Show BGP Summary – Run this test to view the existing BGP neighbor and received routes.
   • Troubleshoot BGP- Show BGP Table – Run this test to view the BGP table.
   • Troubleshoot BGPv6- Show BGPv6 Neighbor Advertised Routes – Run this test to view the BGPv6 routes advertised to a neighbor.
   • Troubleshoot BGPv6- Show BGPv6 Neighbor Learned Routes – Run this test to view all the accepted BGPv6 routes learned from a neighbor after filters.
   • Troubleshoot BGPv6- Show BGPv6 Neighbor Received Routes – Run this test to view all the BGPv6 routes received from a neighbor before filters.
   • Troubleshoot BGPv6- Show BGPv6 Neighbor details – Run this test to view the details of BGPv6 neighbor.
   • Troubleshoot BGPv6- Show BGPv6 Routes per Prefix – Run this test to view all the BGPv6 routes for the prefix and their attributes.
   • Troubleshoot BGPv6- Show BGPv6 Summary – Run this test to view the existing BGPv6 neighbor and received routes.
   • Troubleshoot BGPv6- Show BGPv6 Table – Run this test to view the details of BGPv6 table.

   For more information about all the supported BGP related Remote Diagnostics tests, see the Remote Diagnostic Tests on Edges section in the VeloCloud SD-WAN Troubleshooting Guide.

VeloCloud SD-WAN allows to configure BFD sessions to detect route failures between two connected entities.

1. In the SD-WAN service of the Enterprise portal, select Configure > Profiles .
2. Select the Device Icon for a profile, or select a profile and select the Device tab.
3. In the Device tab, scroll down to the Routing and NAT section and select the arrow next to the BFD area to open it.
4. Select the BFD slider to ON position.
5. Configure the following settings:

   Table 20. Routing and NAT Field Descriptions

   Field	Description
   Peer Address	Enter the IPv4 address of the remote peer to initiate a BFD session. Local Address Enter a locally configured IPv4 address for the peer listener. This address sends the packets. Note: Select the IPv6 tab to configure IPv6 addresses for the remote peer and the peer listener.
   Local Address	For IPv6, the local and peer addresses support only the following format: IPv6 global unicast address (2001:CAFE:0:2::1) IPv6 unique local address (FD00::1234:BEFF:ACE:E0A4)
   Multihop	Select the check box to enable multi-hop for the BFD session. While BFD on Edge and Gateway supports directly connected BFD Sessions, you need to configure BFD peers in conjunction with multi-hop BGP neighbors. The multi-hop BFD option supports this requirement. Multihop must be enabled for the BFD sessions for NSD-BGP-Neighbors.
   Detect Multiplier	Enter the detection time multiplier. The remote transmission interval is multiplied by this value to determine the detection timer for connection loss. The range is from 3 to 50 and the default value is 3.
   Receive Interval	Enter the minimum time interval, in milliseconds, at which the system can receive the control packets from the BFD peer. The range is from 300 to 60000 milliseconds and the default value is 300 milliseconds.
   Transmit Interval	Enter the minimum time interval, in milliseconds, at which the local system can send the BFD control packets. The range is from 300 to 60000 milliseconds and the default value is 300 milliseconds.

6. Select the (+) to add details of more peers.
7. Select Save Changes.

   

   When you configure BFD rules for a profile, the rules are automatically applied to the Edges that are associated with the profile. If required, you can override the configuration for a specific Edge. See Configuring BFD for Edges for more information.

   VeloCloud SD-WAN supports configuring BFD for BGP and OSPF.

   • To enable BFD for BGP, see Configure BFD for BGP for Profiles.
   • To enable BFD for OSPF, see Configure BFD for OSPF.
   • To view the BFD sessions, see Monitor BFD Sessions.
   • To view the BFD events, see Monitor BFD Events.
   • For troubleshooting and debugging BFD, see Troubleshooting BFD.

1. In the SD-WAN service of the Enterprise portal, select Configure > Edges .
2. Select the Device Icon next to an Edge, or select an Edge and select the Device tab.
3. In the Device tab, scroll down to the BFD Rules.
4. Select Override to modify the BFD configuration settings for the selected Edge.

   

5. Select Save Changes.
   VeloCloud SD-WAN supports configuring BFD for BGP and OSPF.

   • To enable BFD for BGP, see Configure BFD for BGP for Profiles.
   • To enable BFD for OSPF, see Configure BFD for OSPF.
   • To view the BFD sessions, see Monitor BFD Sessions.
   • To view the BFD events, see Monitor BFD Events.
   • For troubleshooting and debugging BFD, see Troubleshooting BFD.

Configure BFD for BGP on SD-WAN Profiles.

1. In the SD-WAN service of the Enterprise portal, select Configure > Profiles .
2. Select the Device Icon for a profile, or select a profile and select the Device tab.
3. In the Device tab, scroll down to the Routing & NAT section and select the arrow next to the BGP area to open it.
4. Select the BDF slider to ON position.
5. In the BGP Editor window, select view all in the Additional Options column for a BGP neighbor and select Enable BFD. You can enable a BFD subscription for multiple BGP neighbors, including NSD Neighbors in the 4.3 release.
   Note:

   Multihop must be configured as Multihop BFD for NSD BGP Neighbors in the 4.3 release. For more information about NSD Neighbors, see Configure BGP Over IPsec from Edge to Non SD-WAN Neighbors

   

   Note: BGP over IPsec from the SD-WAN Edge does not support a single-hop BFD session.
6. Configure the other settings as required and select OK.

   When you enable BFD for BGP settings in a profile, the setting automatically applies to the Edges associated with the profile. If required, you can override the configuration for a specific Edge. See Configure BFD for BGP for Edges for more information.

   When a BGP neighbor receives an update that BFD session is down, the corresponding BGP session immediately goes down and the routes learnt through the BGP peer are flushed without waiting for the expiration of a keepalive timer.

You can override the inherited settings at the Edge level for BFD for BGP.

1. In the SD-WAN service of the Enterprise portal, select Configure > Edges .
2. Select the Device Icon next to an Edge, or select an Edge and select the Device tab.
3. In the Device tab, scroll down to the Routing & NAT section and select the arrow next to the BGP area to open it.
4. Select Override and move the slider to the ON position to modify the BGP settings for the selected Edge.

   

1. In the SD-WAN service of the Enterprise portal, select Configure > Profiles .
2. Select a profile and select View from the Device column of the profile. The Device page for the selected profile appears.
3. Navigate to Connectivity and select Interfaces to display the Edge models available for the selected Profile.
4. In the Interfaces section, click an Edge model to view the interfaces available in the Edge and select an interface to edit the settings.
5. On the Interface edit window, you can configure OSPF settings under IPv4/IPv6 Settings. Select OSPF and then select the OSPF Area from the list.

   

6. Expand Advanced Settings and in the Custom Settings, select Enable BFD.
7. Configure the other settings as required and select Save.

   When you enable BFD for an OSPF area in a profile, the setting is automatically applied to the corresponding Edges that are associated with the profile. If required, you can override the configuration for a specific Edge. See Configure BFD for OSPF for Edges for more information.

   When an OSPF neighbor receives an update that BFD session is down, the corresponding OSPF session immediately goes down and the routes are flushed without waiting for the expiration of keepalive timer.

You can modify the inherited Profile settings at the Edge level for BFD for OSPF.

1. In the SD-WAN service of the Enterprise portal, select Configure > Edges .
2. Select an Edge you want to configure BFD for OSPF settings and click the View link in the Device column of the Edge. The Device page for the selected Edge appears.
3. Navigate to Connectivity and select Interfaces.
4. In the Interfaces section, click an interface to edit the settings.
5. On the Interface edit window, you can configure OSPF settings under IPv4/IPv6 Settings. Select OSPF and then select the OSPF Area from the list.

   

6. Expand Advanced Settings and in the Custom Settings tab, select Enable BFD.
7. Configure the required settings for the Edge as required and select Save.

1. In the SD-WAN service of the Enterprise portal, select Configure > Network Services .
2. In the Non SD-WAN Destinations via Gateway area, select Edit in the BFD column that corresponds to the Non SD-WAN Destination.

   

3. In the BFD Editor window, move the BFD Activated slider to the right to turn it on to configure the BFD settings for the Primary and Secondary Gateways.
4. Configure the BFD settings:
   Note: The Secondary Gateway option is available only if you have configured a secondary Gateway for the corresponding Non SD-WAN Destination.

   

   Table 21. BFD Settings Option Descriptions

   Field	Description
   Peer Address	Enter the IP address of the remote peer to initiate a BFD session.
   Local Address	Enter a locally configured IP address for the peer listener. This address is used to send the packets.
   Multihop	This option is not supported for the Gateways.
   Detect Multiplier	Enter the detection time multiplier. The remote transmission interval is multiplied by this value to determine the detection timer for connection loss. The range is from 3 to 50 and the default value is 3.
   Receive Interval	Enter the minimum time interval, in milliseconds, at which the system can receive the control packets from the BFD peer. The range is from 300 to 60000 milliseconds and the default value is 300 milliseconds.
   Transmit Interval	Enter the minimum time interval, in milliseconds, at which the local system can send the BFD control packets. The range is from 300 to 60000 milliseconds and the default value is 300 milliseconds.

   Note: BFD is supported only on VTP Tunnels.

1. In the SD-WAN service of the Enterprise portal, select Monitor > Routing .
2. In the Routing screen, select the BFD tab.
3. Click on Filter next to Search and opt to filter the details by different categories.

   The Edge BFD Sessions table displays the BFD Sessions of the Edge and the Gateway.

   

   The BFD Sessions include the following details for Edges and Gateways:

   • Name of the Edge or Gateway
   • Segment name
   • Peer IPv4 or IPv6 address
   • Local IPv4 or IPv6 address
   • State of the BFD session
   • Remote and Local timers
   • Number of Events
   • Duration of the BFD session

   Click an Event number to view the details of the events.

Run Remote Diagnostics tests to view the logs of the BFD sessions and use the log information for troubleshooting purposes.

1. In the SD-WAN service of the Enterprise Portal, select Diagnostics > Remote Diagnostics .
2. The Remote Diagnostics page displays all the active Edges.
3. Select the Edge that you want to troubleshoot. The Edge enters live mode and displays all the possible Remote Diagnostics tests than you can run on the Edge.
4. For troubleshooting BFD sessions, scroll to the following sections and run the tests:
   • Troubleshoot BFD- Show BFD Peer Status – Choose the Segment from the drop-down list. Enter the Peer and Local IP addresses of an already configured BFD session. select Run to view the details of the BFD peers.
   • Troubleshoot BFD- Show BFD Peer counters – Choose the Segment from the drop-down list. Enter the Peer and Local IP addresses of an already configured BFD session. Select Run to view the details of counters of the BFD peers.
   • Troubleshoot BFD- Show BFD Setting – Select Run to view the details of BFDv4 settings and status of neighbors.
   • Troubleshoot BFD6- Show BFD6 Setting – Select Run to view the details of BFDv6 settings and status of neighbors.

   For more information about all the supported BFD-related Remote Diagnostics tests, see the Remote Diagnostic Tests on Edges section in the VeloCloud SD-WAN Troubleshooting Guide.