Static and dynamic routing, RPF problems, default routes

[vex]

Hello.

I have 3 subnets /28 and 1 subnet /29 that are routed over PTP /30 link. And default route is added as static in routing table.

Recently my organization acquired AS number and new /24 subnet. I made BGP with one provider that is also provider of old subnets mentioned above. They are sending me only default route.

My problem is that default route learned from BGP is not injected into routing table because of static default route. So all outbound traffic with new subnet over BGP is done with policy routing and it is working but inbound traffic that comes on BGP peer interface is dropped because of RPF. It checks path and drops packet.

I have to change all public addresses from old ranges to new range. It would be great if both ranges are available at the same time from outside so that I can gradually switch.

My provider tried with full BGP table but behavior is the same.

Is there a way to have both default routes in main table so that I don't have to kill static route and then rely on faith that everything will be fine when switching all IP addresses in one night?

Help would be much appreciated.

[vex]

This works like a charm. 

Thank you for clearing my doubts.

[akristof]

Hey,

Can you share with us:

get router info routing-table all

get router info routing-table data

get router info bgp network 0.0.0.0/0

[vex]

Hi.

I'm sharing only relevant routes. All other are either static or connected.

get router info routing-table all:

Routing table for VRF=0
S* 0.0.0.0/0 [10/0] via 82.193.209.233, port24, [1/0]

get router info routing-table data:

Routing table for VRF=0
B 0.0.0.0/0 [20/0] via 188.129.9.53 (recursive is directly connected, port22), 6d02h56m
S *> 0.0.0.0/0 [10/0] via 82.193.209.233, port24, [1/0]

get router info bgp network 0.0.0.0/0:

VRF 0 BGP routing table entry for 0.0.0.0/0
Paths: (1 available, best #1, table Default-IP-Routing-Table)
Not advertised to any peer
Original VRF 0
15994
188.129.9.53 from 188.129.9.53 (188.129.9.254)
Origin IGP metric 0, localpref 100, valid, external, best
Last update: Thu Feb 9 10:39:59 2023