INE R&S ATC038 - Backup Interface

Backup Interface

• Tracks line protocol of “primary” interface
– If line protocol is up, “backup” interface is in standby
– If line protocol is down, “backup” interface is active

• Configuration
– backup [interface | load | delay]
– Placed on the primary interface
• What causes the line protocol to go down?

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範例為使用R5 S0/0/0(Frame-Relay)為主要的線路...S0/1/0為備援線路



手動shutdown主要線路...如下圖...會造成backup interface disable...
我們需要的是 up/down...才能驅動backup interface

 

針對R5 S0/0/0 Main Multipoint Frame-Relay Interface 介面以及line protocol都是 up/up
很難造成line protocol down...因為很多 PVC 都是 up ... 當然是可以改lmi type為ansi...
但這就不是我們要的....因為這是故意斷線...

所以需要慎選你的 Primary Interface 及 Backup Interface...

可以用 debug backup 確認...

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Cisco IOS Software Releases 12.4 T - Dial and Access
Cisco IOS Dial Technologies Configuration Guide, Release 12.4T
  Part 6: Dial-Backup Configuration
    Configuring Dial Backup for Serial Lines
http://www.cisco.com/en/US/docs/ios/dial/configuration/guide/dia_backup_serial_ps6441_TSD_Products_Configuration_Guide_Chapter.html