BGP default information originate

[mautez_mah]

Hi Gentle 
in ISP cloud there is VRF for each customer as you know 
one customer has connected to all branches thru MPLS or DATA links , 
we used BGP under VRF >>
now if I need all branches to receive default from H.O in order to reach H.O then we can control traffic to pass another link for internet >>
can I add this command under BGP/VRF in PE which is connected to H.O 
default-information originate
so it will be like that 
router bgp ( AS for ISP )
address-family ipv4 vrf XXX 

nei XXXX ( IP of customer CE H.O ) 

default-information originate
so all branches will receive default from H.O in their routering tables 

[Giuseppe Larosa]

Hello @mautez_mah ,

if you have a default route installed in the VRF routing table

it is enough

router bgp   <ASN>

address-family ipv4 vrf XXX

network 0.0.0.0

instead of using the command for each branch BGP neighbor

edit: I see that you need to use it only to HO CE router

Hope to help

Giuseppe

[mautez_mah]

THanks , 

I will not use the command for each neighour ,
I will use it only under BGP in PE which is connected to CE/H.O ,
so all branches will receive default, right ? 
but I have to install default in customer router right ?

ok what is the use of this command default-information originate if I can add this command Network 0.0.0.0 

[Harold Ritter]

Hi @mautez_mah ,

The command "default-information originate" allows redistribution of the default route into BGP. So unless you combine it with a redistribute statement, it does nothing. 

As mentioned by @Giuseppe Larosa , you can use the "network 0.0.0.0" to inject the default route into BGP, but the default route needs to be already present in the VRF for this to work.

Regards,

[mautez_mah]

you can use the "network 0.0.0.0" to inject the default route into BGP, but the default route needs to be already present in the VRF for this to work.

can u explain more plz 

if I am on CE-Router and just add network 0.0.0.0 under BGP so it will advertize to PE which is under VRF so the default will be advertized to all PE under same VRF, right ? 

[Giuseppe Larosa]

Hello @mautez_mah ,

>> if I am on CE-Router and just add network 0.0.0.0 under BGP so it will advertize to PE which is under VRF so the default will be advertized to all PE under same VRF, right ? 

Yes , but only if the CE router has a default route installed in its IP routing table for example a static route pointing to an internet connection different from the PE-CE link.

Hope to help

Giuseppe

[mautez_mah]

clear, really perfect 

last thing so in this case 
either I have a default route installed in the routing table in order to advertise it thru the Network command

or I can use redistribution static for (0.0.0.0)  and default-information originate on PE  router in order to advertise  default to all PEs under same VRF,