I have client with 2 ISPs/Dual routers. ISP-A :10Meg & ISP-B : T1
Local public IP space advertised to ISPA & ISPB via EBGP (with ISP-B : via AS-Prepend). LAN side of the routers has HSRP config to have ISP-A Connected router as Primary and IBGP config as well.
I would like to implement 'BGP Conditional Advertisement' so that ISP-B will strictly be backup (as ISP-B does not support any communmities). I want to create the NON-EXIST map such a way when ISP-B router not seeing 0.0.0.0 being advertised from ISP-A AS, then ISP-B will be used. Please see the attached info from both the routers.
(attached as the o/p copy& paste here not sitting in better way)
As the Backup router learning 0.0.0.0 from backup ISP (preferred *>) as well as from IBGP via primary ISP AS#, if conditional adverisement applied and in case if BGP with Primary ISP does down, will the secondary ISP takes over (as 0.0.0.0 from priamry willbe gone).
How much time normally it takes for the take over - 3mins..??