12-11-2005 08:57 AM - edited 03-03-2019 11:12 AM
Hi,
How are the default routes configured in one internal router transmitted to other internal router in an area ? Is it by Type 5 LSA ? Then it should be transmitted to all through the AS as Type 5.Correct me if I am wrong.
Thanks,
Vijay
Solved! Go to Solution.
12-14-2005 03:03 AM
Hi Vijay,
As soon as an OSPF router originates a type-5 LSA that carries the default route it becomes an ASBR, even if it does not originate any other external routes.
If you try this out on a router, you will see that this router will now set the E-bit in its router-LSA (type-1 LSA), signifying that it considers itself to be an ASBR.
Paresh.
12-12-2005 08:51 PM
Hi,
If you inject a default route by means of default-information originate, this will be carried to all non-stub areas in a type-5 LSA.
Paresh.
12-13-2005 02:48 AM
Hi,
For a router to generate Type 5 LSAs, it should be an ASBR.But, how come an ordinary router generate a Type 5 LSA to carry default route ? or Only ASBR router can advertise default route? Correct me if I am wrong.
Thanks,
Vijay
12-13-2005 03:02 AM
Nopes it is not needed for a Router to be ASBR to generate default. An ABR can generate a NSSA Default ROute ( The route will be N1 and N2 not E1 and E2). A totally stub area would have an IA default Route not an external default route which is genrated with default-information originate
12-14-2005 01:32 AM
Hi,
I am not talking about default route generated by ABR(as Type 3 LSA for Stubby Area and as Type 7 LSA for NSSA).I am just talking about the default route generated by a normal router inside a noram area.
I got the document:
http://cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00801ec9f0.shtml
which says 'Default routes injected into a normal area can be originated by any OSPF router'
Thanks,
Vijay
12-14-2005 03:03 AM
Hi Vijay,
As soon as an OSPF router originates a type-5 LSA that carries the default route it becomes an ASBR, even if it does not originate any other external routes.
If you try this out on a router, you will see that this router will now set the E-bit in its router-LSA (type-1 LSA), signifying that it considers itself to be an ASBR.
Paresh.
12-14-2005 04:11 AM
Hi,
Thanks for your explanation.
Thanks,
Vijay
Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: