Users Guide

update-source-ip
Configures a source IP interface for any leaked route in a VRF instance.
Syntax
update-source-ip interface interface-id
To undo this configuration, use the no update-source-ip command.
Parameters
● interface interface-id — Enter the loopback interface identifier. The range is from 0 to
16383.
Default Not configured
Command Mode VRF CONFIGURATION
Example
OS10(conf-vrf)# update-source-ip loopback 1
Supported
Releases
10.4.2E or later.
Bidirectional Forwarding Detection
The Bidirectional Forwarding Detection (BFD) protocol rapidly detects communication failures between two adjacent routers.
BFD replaces link-state detection mechanisms in existing routing protocols. It also provides a failure detection solution for links
with no routing protocols.
BFD provides forwarding-path failure detection in milliseconds instead of seconds. Because BFD is independent of routing
protocols, it provides consistent network failure detection. BFD eliminates multiple protocol-dependent timers and methods.
Networks converge is faster because BFD triggers link-state changes in the routing protocol sooner and more consistently.
BFD is a simple hello mechanism. Two neighboring routers running BFD establish a session using a three-way handshake. After
the session is established, the routers exchange periodic control packets at sub-second intervals. If a router does not receive a
hello packet within the specified time, routing protocols are notified that the forwarding path is down.
In addition, BFD sends a control packet when there is a state change or change in a session parameter. These control packets
are sent without regard to transmit and receive intervals in a routing protocol.
BFD is an independent and generic protocol, which all media, topologies, and routing protocols can support using any
encapsulation. OS10 implements BFD at Layer 3 (L3) and with User Datagram Protocol (UDP) encapsulation. BFD is supported
on static and dynamic routing protocols, such as VRRP, OSPF, OSPFv3, IS-IS, and BGP.
The system displays BFD state change notifications.
NOTE: BFD is only supported for the border gateway protocol (BGP).
Configuration notes
All Dell EMC PowerSwitches except MX-Series, S4200-Series, S5200 Series, and Z9332F-ON:
Bidirectional forwarding detection (BFD) is not supported on the S5148F-ON switch.
BFD session states
To establish a BFD session between two routers, enable BFD on both sides of the link. BFD routers can operate in both active
and passive roles.
● The active router starts the BFD session. Both routers can be active in the same session.
● The passive router does not start a session. It only responds to a request for session initialization from the active router.
A BFD session can occur in Asynchronous and Demand modes. However, OS10 BFD supports only Asynchronous mode.
● In Asynchronous mode, both systems send periodic control messages at a specified interval to indicate that their session
status is Up.
● In Demand mode, if one router requests Demand mode, the other router stops sending periodic control packets; it only sends
a response to status inquiries from the Demand mode initiator. Either peer router, but not both, can request Demand mode
at any time.
Layer 3
763