12-03-2008 09:18 AM - edited 03-04-2019 12:35 AM
Hi to all,
Is it possible to redistribute a default route using ospf multiarea just in one area??
For example if i have my area 0 for backbone and my area 1 for my locations can I redistribute a default route just to the area 1????
Thanks in advance
Solved! Go to Solution.
12-04-2008 01:13 AM
Hello Alfonso,
please do the following:
on ABR:
router ospf 10
no default-information originate always
no default-information originate
Some OSPF commands are tricky : if you make a single no the router just denies the always option and you need to give it a second time there is no other explanation for the O E2 default route still in area 0
Hope to help
Giuseppe
12-03-2008 09:30 AM
hi Alfonso,
I'm not sure what you want. If you want all routers in area 1 to get only "default route". You can use "Totally Stub Area" in area 1. ABR will inject only default route to all routers in that area. It does protect LSA type 3 and 5 from being injected to that area.
Toshi
12-03-2008 09:39 AM
Hi Toshi,
This is the scenario, I have my area 0 for backbone and my area 1 for my locations and what i need is that the routers that are in my area 1 plus knowing all the routes that the ospf process gives them also to have a default route given by ospf too, if i put the command default-information originate always the ospf process redistribute the default route to the area 1 but also to the area 0 and that's not what i need, i need the default route to be redistributed only in my area 1.
Thanks in advance.
12-03-2008 10:25 AM
Alfonso,
First of all, You are using "default-information originate always" that means no need to have a default route in RIB to advertise a default route. So Redistributing a default route is not needed. Your requirement is to filter LSA Type 5 (default information originate) to inject to area 0. I don't think that area filter-list commands will help you because it should filter LSA Type 3. As I mentioned above that would meet a requirement. But if this is a scenario to accomplish. Frankly I'm waiting for how it works... (grin)
Edit : if the requirements are allowed to use "distrition-list in" commands. I would apply it on all routers in area0 to get rid of a default route. It's not nice anyway!!
Toshi
12-03-2008 11:21 AM
Hello Alfonso, Toshi
if there aren't LSA type 5 external in the OSPF database a stub area satisfies all the requirements:
it receives all the OSPF routes (if no external routes)
it receives a default route from ABR router
I would consider this option.
Hope to help
Giuseppe
12-03-2008 12:12 PM
Hi Giuseppe,
You mean that i should configure my area 0 as a stub area in order to not to get the default route redistributed by the ospf process??? and only the area 1 is going to get it...I'm I right???
Thanks in advance.
12-03-2008 12:23 PM
Hi Giuseppe,
Sorry, i ment the area 1 to be configure as a stub area.
12-03-2008 01:08 PM
hello Alfonso,
yes the idea is :
remove the default-information originate
make area 1 a stub area
this makes ABR to automatically injects an O IA default router inside area 1
This is usually an acceptable solution: even if there are filtered external routes the default route allows to reach all prefixes known in the OSPF domain
Hope to help
Giuseppe
12-03-2008 01:31 PM
Hi Giuseppe,
I did that, but in my routers where i just have area 0 I'm getting a default route given by my ABR O*E2 0.0.0.0/0 [110/1] via 172.16.1.1, 00:11:19, Serial0/1/0 and also in the routers that are in area 1 I'm having the default route that I want O*IA 0.0.0.0/0 [110/260] via 192.168.1.1, 00:08:35, FastEthernet0/0
But that default route on the area 0 is making me to have problems.
Config on ABR
router ospf 100
log-adjacency-changes
area 1 stub
network 192.168.2.0 0.0.0.3 area 1
network 192.168.3.0 0.0.0.3 area 1
network 192.168.5.0 0.0.0.255 area 1
network 172.16.1.0 0.0.0.3 area 0
!
ip classless
ip route 0.0.0.0 0.0.0.0 201.147.155.1
Config on a Location
router ospf 100
log-adjacency-changes
area 1 stub
network 192.168.1.0 0.0.0.3 area 1
network 192.168.4.0 0.0.0.3 area 1
network 192.168.6.0 0.0.0.255 area 1
Thanks in advance
12-03-2008 01:20 PM
Hi Giuseppe,
Sorry, i ment the area 1 to be configure as a stub area.
12-04-2008 01:13 AM
Hello Alfonso,
please do the following:
on ABR:
router ospf 10
no default-information originate always
no default-information originate
Some OSPF commands are tricky : if you make a single no the router just denies the always option and you need to give it a second time there is no other explanation for the O E2 default route still in area 0
Hope to help
Giuseppe
12-04-2008 11:45 AM
Hi Giuseppe,
I did that and also restart the ospf process and it worked well, now I have the default route just on the area 1.
Thanks alot for your help!
12-11-2022 04:02 AM
Hello Giuseppe
Do you mean on area 1 ABR? but I will use default-information on it. How I could use no default-information?
Thank you.
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