ISR4431 High Availibility

[Sun Flower]

I am planning to configure High availability between 2 Cisco ISR4431 router. There are 2 options to configure HA which is Interchassis and Bidirectional forwarding. So what is the main difference between Interchassis and BFD? 

[Philip D'Ath]

I wouldn't normally have described those two as related.

BFD is concerned with detecting a link failure quickly.

https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bfd/configuration/xe-3s/irb-xe-3s-book/irb-bi-fwd-det.html

Interchassis support is where you mirror one router onto another router.

https://www.cisco.com/c/en/us/td/docs/routers/access/4400/software/configuration/guide/isr4400swcfg/bm_isr_4400_sw_config_guide_chapter_01100.html#concept_8FA17F8A3DED47719A552D56871EDFCE