Tech Tip - Dynamic Routing: Default Originate

[Chris_Atkinson]

Background:

Default Originate

In Cisco BGP routing environments "default originate" is provided as a mechanism to advertise a default route prefix (0.0.0.0/0) to BGP peers without the need for installing that same route into the local OS routing table. 

GAiA OS has similarly named commands however their operation / use differs somewhat from other vendors implementations of "default originate" who've aligned to the Cisco approach:

default-route-gateway {<IP Address> | off}
suppress-default-originate {off | on}

NAT Pools
Used as a method of anchoring routes for redistribution such as subnets used for NAT or Remote Access VPN client IP ranges that terminate on the Gateway itself. When used for the purposes of redistributing networks into a routing protocol such as OSPF and BGP this helps to ensure that the wider network has a means of awareness / reachability to these IP ranges that they otherwise might not. In a sense they can serve a similar purpose to Loopbacks.

Check Point R82 Gaia Advanced Routing Admin Guide - NAT Pools

Solution:

Configuring a NAT Pool of 0.0.0.0/0 can be used to achieve the fundamental "default originate" use case when coupled with route redistribution / route-maps for granular control of the relevant routing advertisements.
(Note: Configuration was implemented via CLI & tested on VSX.)

sk183734: BGP default-route-gateway to originate a BGP default route (since merged into admin guide).

[the_rock]

Very helpful, Chris 👍