At the moment this network is working correctly as an example out of Falcon ping the loopback of router
one and it can ping gigabit zero zero on router one router one can ping the loopback of router four
and can ping.
The Gigabit zero zero interface on router four.
But in the same way as you have with OSPF version two, you can enable.
Passive interfaces.
So if we use the command passive interface.
Default.
That'll make all interfaces passive.
In other words, the Rada Rada three.
Will not form neighbor relationships on these interfaces or send updates out of those interfaces.
So you can see both neighbor relationships have come down.
Show.
IPV six OSPF neighbor.
They are no neighbor relationships.
Rather one is no longer able to ping rather for.
And rather too we can see that the neighbor relationship has gone down.
Show IPV six OSPF neighbor.
We only have one neighbor relationship.
So from a troubleshooting point of view, if you can't ping through an OSPF network, check that the
neighbor relationships are established.
If the neighbor relationships aren't established, check that OSPF is enabled on all the relevant interfaces
in the right areas.
So make sure that your areas are configured correctly on the relevant interfaces.
So rather three doesn't have a neighbor relationship.
Make sure that OSPF is enabled on the relevant interfaces.
If it is enabled on the interfaces, check your configuration and make sure that you haven't got passive
interfaces.
So as an example here we can see that all interfaces have gone passive.
Or we could use the command show IPV six OSPF interface.
I notice we have this output.
No hellos, passive interface.
And we can see that on gigabit is zero one.
And we can see that on gigabit zero zero.
So check that passive hasn't been configured on the router.
So in this example, what I'll do is disable the passive interface on gigabit zero zero.
So no passive interface interface.
Gigabit zero zero.
And what we should see is that a neighbor relationship is formed and there you go.
So do show IPV six OSPF neighbor.
We can see a neighbor relationship has been established on gigabit zero zero and we could do something
similar on gigabit zero one.
And notice the neighbor relationship has come up.
So be careful with passive interface.
You can set up a one passive interface like gigabit zero one, or you can enable passive interfaces
globally and then disable them.
To do.
So run pipe begin OSPF.
Notice this configuration, we've enabled default passive interfaces, so all interfaces will be passive,
but then we've overridden the passive option on this interface.
And this interface.
Typically you only enable passive interfaces on links to external networks or to user facing VLANs as
an example where you don't want your users to learn OSPF routes.
Another issue may be that OSPF wasn't enabled on an interface.
So do show run interface gigabit.
Zero one.
If this command wasn't configured, the relationship would not form on that interface.
So do show IPV six OSPF neighbor.
Shows us that no neighbor relationship exists on gigabit zero one and that's where this come on do show
IPV six OSPF interface brief is very useful.
We can see very quickly that OSPF was not enabled on this interface.
Now.
What happens if the wrong area was used?
Do show IPV six ospf.
Neighbor.
No neighbor relationship is established.
But note we are getting a warning message about an area mismatch.
We received an update with the incorrect area.
So our local area is three, but the remote area is two.
So we are warned by the rudder about that problem.
So we need to configure the right area and as soon as we do that our neighbour relationship is established.
So be aware that the same troubleshooting options exist in OSPF version three as you have an OSPF version
to the show.
Commands are very similar, output is very similar, the logic is very similar.
But you're using IP version six addresses and protocols rather than IP version for.