Wired Intelligent Edge

Hi Folks, 

Seeking you expertise, how can i advertise, or is this is the good practice. 
The scenario is, the three sites are participating in OSPF area-0 (DC1, DC2 and Aruba 8320)

Can we summarize the advertisement from 8320 into /21, take note that 8320 is only participating in AREA-0, no other OSPF area behind.
If yes, what is the corresponding configuration, and If NO, why?



Thanks In advance..

Hi,

OSPF can summarise, but not within an area as OSPF can only summarise type 3  & 5  LSAs at the ABR or ASBR level.

If you converted the 8320 to an ABR you could then summarise addressing ( providing there are no route address conflicts). You would have to check to see if this is practical.

Regards,

------------------------------
Steve Bartlett
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Original Message:
Sent: Sep 30, 2021 04:42 AM
From: Rommel Lualhati
Subject: 8320 - OSPF Summarize Address Advertisement

Hi Folks, 

Seeking you expertise, how can i advertise, or is this is the good practice. 
The scenario is, the three sites are participating in OSPF area-0 (DC1, DC2 and Aruba 8320)

Can we summarize the advertisement from 8320 into /21, take note that 8320 is only participating in AREA-0, no other OSPF area behind.
If yes, what is the corresponding configuration, and If NO, why?



Thanks In advance..

Hello!

OSPF is a link-state protocol and inside one single area (Area 0 in your example) it generates LSA for each link (and subnet associated with it). There is no way to summarize routes inside one area as summarization happens only on the border between areas (by ABR) or between autonomous systems (by ASBR) If you really need to perform such summarization, make another area behind CORE-SW and put your LAN Networks there. Thus CORE-SW will become an ABR and then it will summarize those networks towards DC1 and DC2 inside LSA Type 3 automatically.


------------------------------
Ivan Bondar
------------------------------

Original Message:
Sent: Sep 30, 2021 04:42 AM
From: Rommel Lualhati
Subject: 8320 - OSPF Summarize Address Advertisement

Hi Folks, 

Seeking you expertise, how can i advertise, or is this is the good practice. 
The scenario is, the three sites are participating in OSPF area-0 (DC1, DC2 and Aruba 8320)

Can we summarize the advertisement from 8320 into /21, take note that 8320 is only participating in AREA-0, no other OSPF area behind.
If yes, what is the corresponding configuration, and If NO, why?



Thanks In advance..

Hello!

OSPF is a link-state protocol and inside one single area (Area 0 in your example) it generates LSA for each link (and subnet associated with it). There is no way to summarize routes inside one area as summarization happens only on the border between areas (by ABR) or between autonomous systems (by ASBR) If you really need to perform such summarization, make another area behind CORE-SW and put your LAN Networks there. Thus CORE-SW will become an ABR and then it will summarize those networks towards DC1 and DC2 inside LSA Type 3 automatically.

------------------------------
Best regards,
Ivan
------------------------------

Original Message:
Sent: Sep 30, 2021 04:42 AM
From: Rommel Lualhati
Subject: 8320 - OSPF Summarize Address Advertisement

Hi Folks, 

Seeking you expertise, how can i advertise, or is this is the good practice. 
The scenario is, the three sites are participating in OSPF area-0 (DC1, DC2 and Aruba 8320)

Can we summarize the advertisement from 8320 into /21, take note that 8320 is only participating in AREA-0, no other OSPF area behind.
If yes, what is the corresponding configuration, and If NO, why?



Thanks In advance..