INE R&S ATC022 - Flex Links

FlexLinks

• Allowslink redundancy without STP
– Primary link forwards while backup link blocks
– switchport backup interface
• MAC-Address Move Update allows for faster convergence of CAM
– mac address-table move update [receive | transmit]
– switchport backup interface [int] mmu primary

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SW2 use Fa0/17 as Primary Link to SW3 , Fa0/13 as Backup Link to SW1, SW1 to SW3

@SW2

int fa0/17
  switchport backup intface fa0/13
  switchport backup intface fa0/13 mmu primary vlan 1
  switchport backup intface fa0/13 preemption mode forced 
  switchport backup intface fa0/13 preemption delay 35
exit
macaddress-table move update transmit

@ SW3 and SW1 - the upstream switch the following needs to be configured to accept the MAC address-table move update packets.

macaddress-table move update receive

Catalyst 3560 Switch Software Configuration Guide, Rel. 12.2(46)SE

- Configuring Flex Links and the MAC Address-Table Move Update Feature

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_46_se/configuration/guide/swflink.html

show interfaces [interface-id] switchport backup
show mac address-table move update