Failover BGP If There Are Intermitten Link

[Rahadian]

Hi All, 

I have 6 BGP tunnel neighboring to AWS, they are used for redundancy with sequencing manner (Tunnel 1 -> Tunnel 6). I want it to failover if there are 10% Packet Loss in the link. Currently if there is intermitten the BGP won't change to next best available neighbor, so we have to shut it manually. Are there any suggestion / experience to failover it automatically ?

Thanks

[funkylicious]

Hi,

Something like what you are describing is mentioned under the SDWAN config, https://docs.fortinet.com/document/fortigate/6.2.16/cookbook/256748/controlling-traffic-with-bgp-rou... , but it will require from your part for some changes in order to configure the SDWAN part if it's not already in place.

Another good link to read about , https://docs.fortinet.com/document/fortigate/7.0.0/sd-wan-self-healing-with-bgp/559415/overview

[Rahadian]

Hi funkylicious,

Thank you for responding, are there any alternative to control the the incoming traffic from our Fortigate only ? since we didn't manage the device on the other end ?

Thanks

[Richie_C]

For a BGP solution, you should look into route dampening. Here is an example from a Fortiswitch document. However, the theory would be the same for a FortiGate.

https://docs.fortinet.com/document/fortiswitch/7.2.7/administration-guide/939736/troubleshooting-bgp....

Thanks

[funkylicious]

To be honest, I havent tested this scenario, but I think that you can try to use the routemap for IN and manipulate some bgp attributes ( like localpref or as-prepend ) based on the SLA to exit a different link/neighbour but this could lead to asymmetric routing at the other end.