How to advertise default route over iBGP only if it's present in the routing table

General questions
1

Hey all, I’m trying to connect two VyOS routers to my Aruba 5406R using iBGP (one for primary WAN, and one for secondary). I have peering working, and my VLANs on the 5406 propagate to all of the DMVPN sites. The last thing I need to configure is the default routing. I’m using routing to handle WAN failovers, so I need VyOS to stop advertising a default route when it disappears from its own routing table. Right now, VyOS is advertising a default route even when it’s not present in its own routing table. In the VyOS BGP docs, it says I can use a route map to advertise this only when certain conditions are met, but there are no examples or anything and I’ve never used a route map before. How would I go about configuring this behavior?

Additional but related question: pfSense (which also uses FRR) will stop advertising a default route if it detects the upstream gateway has gone down. Does VyOS behave the same way? If not by default, is there a way to achieve this same behavior?

This is how I configured BGP to advertise the default route: set protocols bgp neighbor 10.5.3.40 address-family ipv4-unicast default-originate

Thank you for your time!

2

Don’t originate default route from this host itself. Just export default route from your uplink

3

Thank you for the reply!

Ok, I understand not using VyOS BGP to originate the default route - but I’m missing what you mean when you say “export default route from your uplink”

Could you elaborate for someone who is new to VyOS and relatively new to dynamic routing protocols?

Thanks again for your help!

4

Do you import default route from external bgp session from your ISP?

5

No, ISP handoff is a standard DOCSIS modem with dynamic IP.