Question about MPLS vpnv4 prefix default advertisement

Routing & Switching MPLS
1

Hi guys, I´ve a question about the default route advetisement under MPLS backbone.
The client A (vrf_a) only has static routing at both sites (X, Y) in my MPLS backbone, he needs to advetise the static route 0.0.0.0/0 from site X to site Y but it doesn´t propagate to the rest of MPLS network, why?
this is my configuration:

router bgp 22345
 rd 22345:800
  address-family ipv4 unicast
   redistribute connected
   redistribute static
  !
 !
router static
 vrf vrf_a
  address-family ipv4 unicast
   0.0.0.0/0 10.21.200.186 description default_route
   192.168.201.0/24 10.21.242.186 description LAN_MATRIZ

only the specific route 192.168.201.0/24 is propagated, but the default 0.0.0.0/0 doesn´t.

Only if I set the command default-information originate under BGP vrf_a instance the default route is propagated, why? is this a correct behavour?
Please your feedback.

Thanks in advance.

2

Hello Javier

In your case it looks like you’re using BGP between your CE and PE devices. Remember that when using BGP, you can advertise networks in two ways: redistribution and by using the network command. This is detailed in the following lesson:

In your configuration, I see you have used redistribution, and in particular, the redistribution of connected and static routes. This is why your 192.168.201.0/24 is propagated.

However, BGP will not advertise a default route using redistribution. It must be done using the default information-originate command that you correctly realized will solve your problem. The reason it must be implemented in this way is detailed in the following post:

I hope this has been helpful!

Laz