Regardless of the culprit, the cause of this will be a misconfiguration of some
kind and likely not even with OSPF. OSPF is not weird, nor does it behave
badly; it merely reacts to conditions based on a predetermined set of
algorithms which are very well documented and implemented, especially for IPv4.
OSPF builds a FIB and based on that FIB, it modifies the route table. Both of
those are correct in this case.
All that said, I fully embrace the model you laid it and have been using it for
some time. It makes perfect sense to me to use a non-link-state protocol to
distribute prefixes that are not based on the state of a link.
Now, if we can just get Mikrotik to work out the next-hop recursive resolution
issue so we can use BGP to distribute v6 prefixes...
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On Thu, Aug 25, 2016 at 5:28 PM -0600, "Bruce Robertson" <br...@pooh.com> wrote:
I've said it before, and been argued with... this is one of many
reasons why you use iBGP to distribute {customer, dynamic pool,
server subnets, anything} routes, and use OSPF *only* to distribute
router loopback addresses.� All your weird OSPF problems will go
away.� My apologies if I'm misunderstanding the problem, but my
point still stands.
On 08/25/2016 10:22 AM, Robert Haas
wrote:
Alright, this problem has raised it head
again on my network since I started to renumber some PPPoE
pools.
Customer gets a new IP address via PPPoE
x.x.x.208/32 (from x.x.x.192/27 pool). Customer can�t surf and
I can�t ping them from my office:
�
[office] � [Bernie Router] � [Braggcity
Router] � [Ross Router] � [Hayti Router] � [customer]
�
A traceroute from my office dies @ the
Bernie router but I am not getting any type of ICMP response
from the Bernie router ie no ICMP Host Unreachable/Dest
unreachable etc � just blackholes after my office router.
A traceroute from the Customer to the
office again dies at the Bernie router with no type of
response.
�
Checking the routing table on the Bernie
router shows a valid route pointing to the Braggcity router.
It is also in the OSPF LSA�s.
--
Another customer gets x.x.x.207/32 and has
no issue at all.
�
--
Force the original customer to a new ip
address of x.x.x.205/32 and the service starts working again.
�
--
�
Now � even though there is no valid route
to x.x.x.208/32 in the routing table � traffic destined to the
x.x.x.208/32 IP is still getting blackholed.. I should be
getting a Destination host unreachable from the Bernie router.
�
This is correct the correct response .206
is not being used and there is no route to it:
C:\Users
etadmin>ping x.x.x.206
�
Pinging x.x.x.206 with 32 bytes of data:
Reply from y.y.y.1: Destination host
unreachable.
Reply from y.y.y.1: Destination host
unreachable.
�
Ping statistics for x.x.x.206:
��� Packets: Sent = 2, Received = 2, Lost =
0 (0% loss),
�
C:\Users
etadmin>tracert 74.91.65.206
�
Tracing route to
host-x.x.x.206.bpsnetworks.com [x.x.x.206]
over a maximum of 30 hops:
�
� 1���� 6 ms���� 6 ms���� 7 ms� z.z.z.z
� 2���� 6 ms���� 6 ms���� 6 ms�
y.bpsnetworks.com [y.y.y.1]
� 3� y.bpsnetworks.com [y.y.y.1] �reports:
Destination host unreachable.
�
Trace complete.
�
This is what I see to x.x.x.208 even though
it is not being used and there is no route to it.
C:\Users
etadmin>ping x.x.x.208
�
Pinging x.x.x.208 with 32 bytes of data:
Request timed out.
Request timed out.
�
Ping statistics for x.x.x.208:
��� Packets: Sent = 2, Received = 0, Lost =
2 (100% loss),
�
C:\Users
etadmin>tracert x.x.x.208
�
Tracing route to
host-x.x.x.208.bpsnetworks.com [x.x.x.208]
over a maximum of 30 hops:
�
� 1���� 6 ms���� 6 ms���� 6 ms� z.z.z.z
� 2���� *������� *������� *����
Request
timed out.
� 3���� *������� *���� ^C
�
--
�
I�ve verified there is no firewall that
would affect the traffic � I even put an accept rule in the
forward chain for both the source and destination of x.x.x.208
and neither increment at all. So the traffic is not even
making out of the routing flow and into the firewall..
�
Any pointers are where to start
troubleshooting next?
!DSPAM:2,57bf295962076342819562!
