Redistribution

BGP 0/0 into IGP

How can one redistribute an iBGP learned default-route (0.0.0.0/0) into an IGP (EIGRP/OSPF/IS-IS)?

The redistribution of iBGP routes into an IGP (EIGRP/OSPF/IS-IS) – can cause routing loops within the Autonomous System, which is not recommended. Hence iBGP redistribution into IGP is disabled by default. Use the bgp redistribute-internal command to enable redistribution of iBGP routes into IGPs. Note that the command is BGP specific and thus will enable default-route redistribution into any IGP redistributing BGP.
Precautions should be taken to redistribute specific routes using route-maps into an IGP. A sample configuration for redistributing an iBGP learned default route 0.0.0.0/0 into EIGRP is shown in this output. Configurations for OSPF/IS-IS are similar.

router bgp 65345

bgp redistribute-internal
!
router eigrp 10


redistribute bgp 65345 route-map check-def
!
ip prefix-list def-route seq 5 permit 0.0.0.0/0
!
route-map check-def permit 10
_match ip address prefix-list def-route

I found the above here.

Redistribution Terminology

area range – Used to consolidate and summarise at an ABR
default-metric – Sets the (default) metrics for routes redistributed into EIGRP, BGP, OSPF and RIP (others aren’t relevant to the CCIE RS track)
distribute-list in – Used to filter received routes before they’re put in a database or failing a DB the routing table
distribute-list out – Used to filter routes from sent routing updates
summary-address – Used to create aggregate routes for OSPF (and IS-IS ;) ), can specify whether to send out the subnets of the aggregate or not.

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