Cisco IOS software images are specific to a Cisco IOS software version, feature set, and platform. Use Cisco Feature Navigator to learn more about platform and software image support. With Cisco Feature Navigator, you can determine which Cisco IOS and Catalyst OS software images support a specific software version, feature set, or platform. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required. Use Cisco Feature Navigator to learn more about platform support and support for Cisco IOS and Catalyst OS software images. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required. • As an additional layer or protection, the network administrator should consider running BFD in conjunction with Cisco IP Event Dampening www.cisco.com/en/US/products/sw/iosswrel/ps1838/products_feature_guide09186a0080134a41.html. •Chapter “IP Routing Protocol Independent Commands” in the Cisco IOS IP Routing Protocols Command Reference, version 12.4T.
The following example does not display the bfd and standby bfd all-interfaces commands. HSRP support for BFD peering is enabled by default when BFD is configured on the router or interface using the bfd interval command. The bfd and standby bfd all-interfaces standby commands are only required if BFD has been manually disabled on a router or interface. Router(config-if)# bfd interval 50 min_rx 50 multiplier 5. The following sections provide references to the BFD function. BFD packets are not reconciled in the QoS policy for self-generated packets. See also the chapter “Configuring BGP Neighboring Session Options,” section “Configuring BFD for IPv6 BGP Neighbors.” Cisco devices use an BFD session for multiple client protocols in the Cisco implementation of BFD for Cisco IOS versions 12.2(18)SXE, 12.0(31)S, and 12.4(4)T. For example, if a network is running OSPF and EIGRP on the same connection with the same peer, only one BFD session is established and BFD shares session information with both routing protocols. For Cisco IOS version 12.2(33)SRC, you can configure BFD support for static routing. • Information Dissemination: The speed at which the error can be communicated to other devices on the network in the previous phase To find and download MIBs for selected platforms, Cisco IOS versions, and feature sets, use Cisco MIB Locator at the following URL: Once a BFD session has been established and the timer negations are complete, BFD peers send BFD control packets that are in the same way that an IGP protocol hello behave to recognize liveliness, except at an accelerated rate. The following information should be noted:.
Cisco IOS Release 15.4(1)S has added support for Cisco ASR 901S series routers. The following example marks a BFD session with 209.165.200.226 on the Ethernet interface 0/0.1001 to use the group test group. In other words, this configuration is a passive static BFD. Although there are static routes that must be followed by the second static BFD configuration, a BFD session for 209.165.200.226 is not triggered through the 0/0.1001 Ethernet interface. The existence of the prefixes 10.1.1.1/8 and 10.2.2.2/8 is controlled by the active static BFD session (Ethernet interface 0/0 209.165.200.225). 4. Millisecond BFD interval min_rx millisecond multiplier multiplier. Checks whether the BFD neighbor is active and displays the routing protocols that BFD has registered.
Since these protocols rely on the underlying PGI to determine their responses to errors, BFD`s ability to help the PGI converge faster benefits all top-layer protocols. In the following example, there is an active static BFD configuration to reach 209.165.200.225 through the Ethernet 0/0 interface in the test group of the BFD group. Once the static route followed by the configured static BFD is configured, a single-hop BFD session to 209.165.200.225 is launched through the Ethernet 0/0 interface. The prefix 10.0.0.0/8 is added to the RIB when a BFD session is successfully established. A BFD multihop session is established between a unique source-destination address pair provided by the client. A session can be configured between two endpoints that have IP connectivity. Support for BFD functionality has been extended to support VPN routing and forwarding (VRF) to enable rapid detection of routing protocol errors between Provider Edge (PE) and Customer Edge (CE) devices. To configure BFD for one or more IS-IS interfaces only, follow the steps in this section. You can enable BFD support for dynamic routing protocols at the router level to enable BFD support globally for all interfaces, or you can configure BFD at the interface-by-interface level. You start a BFD process by configuring BFD on the interface. When the BFD process is started, no entries are created in the adjacency database, that is, no BFD control packets are sent or received.
BFD echo mode, which is supported in BFD version 1 for Cisco IOS 12.4(9)T, is enabled by default. BFD echo packets are sent and received in addition to BFD control packets. Adjacency creation occurs after you configure BFD support for the appropriate routing protocols. This section contains the following procedures:. • Router A and Router B both start in a stationary state, with agreed timers of 50ms in both directions. Hardware-unloaded session timers are supported from 3.3 ms to 200 ms and session timers unloaded by software from 200 ms to 999 ms. A routing protocol must register with BFD for each neighbor it acquires. Once a neighbor is registered, BFD starts a session with the neighbor if there is no session yet.