Fortigate iBGP change router-id

[nejoo]

Hi,

We are running FortiGate SDWAN, with iBGP. One site has a duplicate configured router-id and we need to correct it. What is the impact when doing so? Will BGP go down, or will it just send the next updates with the new router ID https://100001.onl/

[spoojary]

Changing the router ID in BGP may cause the BGP session to flap, leading to temporary disruptions in routing as routes are withdrawn and readvertised with the new router ID.