OSPF and Forcing a Subnet

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1

Dear Friends,
I have an OSPF over GRE configuration sending you below in which I have
problem.
I want to force OSPF to advertise 172.16/16 range without checking anything.
And as you see I have an static route for it in routing table but again
OSPF do not advertise it, only it advertise when I put one /32 subnet on
loopback interface.
even I put "redistribute static subnets" command with/without route-map but
again do not work.
I think because of having my providers address range in my static routes,
routers and ospf confused when wanna advertise routers.

interface Tunnel0

ip address 128.140.40.2 255.255.255.252
tunnel source 10.20.76.2
tunnel destination 10.20.75.2
interface GigabitEthernet0/0
description UPSTREAM - INTRANET
ip address 10.20.76.2 255.255.255.248
interface GigabitEthernet0/1
description CONNECTED ROUTER
ip address 10.20.76.9 255.255.255.248

router ospf 10
log-adjacency-changes
area 10 range 172.16.0.0 255.255.0.0
passive-interface default
no passive-interface Tunnel0
network 172.16.0.0 0.0.255.255 area 10
network 128.140.40.0 0.0.0.3 area 0
ip route 0.0.0.0 0.0.0.0 10.20.76.1
ip route 172.16.0.0 255.255.224.0 10.20.76.12
ip route 10.20.76.0 255.255.255.0 10.20.76.12
ip route 10.20.77.0 255.255.255.0 10.20.76.12

Thanks

2

You don't have a route for 172.16/16 in the config below, so ospf will not advertise it. You do have a route for a subnet of 172.16/16, so either use summary-address 172.16.0.0 255.255.0.0 or nail up a static route for 172.16.0.0 255.255.0.0 to null0 and redistribute static subnets, and then ospf can redistribute that static route.

3

Dear Jon I have a mistake in my last email, there is a static route like
this:

ip route 172.16.0.0 255.255.0.0 10.20.76.12

but again it is redistributing

4

what you are seeing is the expected behavior.

you are asking the router to generate a type 3 summary for a type 1 lsa that doesn't exist for area 10 via the "area 10 range' command" (also, that is why it works when you add a /32 to loopback)

172.16/16 is an external route. If you want to generate a type 5 aggregate use summary-addr as Jon has pointed out. Else, leave static in place, redist static subnets but remove "area 10 range 172.16.0.0 255.255.0.0" from ospf config.
./Randy

5

Dear Randy,
Thanks for your help, but 172.16/16 belong to that region and for example
172.17/16 belong to another one and I want to ospf bring me the whole
subnet not which I used.
And summary-address does not to this for me.
Thanks