The principle of default route advertising for OSPF special area.

Created Mar 20, 2016 20:46:40Latest reply Mar 21, 2016 04:13:45 1094 1 0 0

The principle of default route advertising for OSPF special area.

  • x
  • convention:

Osaideo     Created Mar 21, 2016 04:13:45 Helpful(0) Helpful(0)

Stub area: because the ASBR summary LSA and external LSA can’t be advertised in stub area, so except ABR, the routers in stub area have no external routes. To ensure the routers to access external network, ABR will generate a summary LSA with link-id 0.0.0.0 and with mask 0.0.0.0 that advertises to this stub area.
Totally stub area: The difference between totally stub area and stub area is that in totally stub area, neither ASBR summary LSA and external LSA, nor network summary LSA can be advertised. To ensure the routers to access external network, ABR will generate a summary LSA with link-id 0.0.0.0 and with mask 0.0.0.0 that advertises to this totally stub area.
NSSA area: The difference between NSSA area and stub area is that the ASBR can exist in NSSA area. NSSA area will filter ASBR summary LSA and external LSA from backbone area, but will not include NSSA external LSA from ASBR in it.
ABR will generate a summary LSA with link-id 0.0.0.0 and with mask 0.0.0.0 that advertises to this NSSA area as the default route.
TOTALLY NSSA area: The difference between totally NSSA area and NSSA area is that network summary LSA can’t be advertised in Totally NSSA area. ABR will generate a summary LSA with link-id 0.0.0.0 and with mask 0.0.0.0 that advertises to this totally NSSA area as the default route.
  • x
  • convention:

Responses

Reply
You need to log in to reply to the post Login | Register

Notice:To ensure the legitimate rights and interests of you, the community, and third parties, do not release content that may bring legal risks to all parties, including but not limited to politically sensitive content, content concerning pornography, gambling, drug abuse and trafficking, content that may disclose or infringe upon others' intellectual properties, including commercial secrets, trade marks, copyrights, and patents, and personal privacy. Do not share your account and password with others. All operations performed using your account will be regarded as your own actions and all consequences arising therefrom will be borne by you. For details, see“ Privacy Policy.”
If the attachment button is not available, update the Adobe Flash Player to the latest version!
Fast reply Scroll to top