Cisco Cisco 1700 2600 3600 3700 Series VPN Module 백서
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Figure 27. Dual-Active Detection Using IP-BFD
Bidirectional Forwarding Detection (BFD) assists in the fast detection of a failed VSL, natively bringing in the
benefits that BFD offers, such as subsecond timers and pseudo-preemption. To take advantage of this feature, you
must first configure BFD on the selected interfaces that will be participating in IP-BFD dual-active detection, noting
that these interfaces must be directly connected to each other:
vss#conf t
Enter configuration commands, one per line. End with CNTL/Z.
vss(config)#int gig 1/5/1
vss(config-if)#ip address 10.1.1.1 255.255.255.0
vss(config-if)#bfd interval 100 min_rx 100 multiplier 50
vss(config-if)#no shutdown
vss(config-if)#int gig 2/5/1
vss(config-if)#ip address 10.1.2.1 255.255.255.0
vss(config-if)#bfd interval 100 min_rx 100 multiplier 50
vss(config-if)#no shutdown
vss(config-if)#exit
Note that in a Cisco Virtual Switching System environment, both interfaces are seen to be Layer 3 routed interfaces
on the same logical router and hence require different network addresses even though they are directly connected
together.
To enable IP-BFD for dual-active detection, use the following configuration:
vss(config)#switch virtual domain 10
vss(config-vs-domain)#dual-active detection bfd
vss(config-vs-domain)#dual-active pair interface gig1/5/1 interface gig2/5/1 bfd
adding a static route 10.1.2.0 255.255.255.0 Gi1/5/1 for this dual-active pair
adding a static route 10.1.1.0 255.255.255.0 Gi2/5/1 for this dual-active pair
vss#show switch virtual dual-active bfd
Bfd dual-active detection enabled: Yes
Bfd dual-active interface pairs configured:
interface-1 Gi1/5/1 interface-2 Gi2/5/1