Just double checked.  If I put an address on a down interface it does go
into the routing table as a directly connected, but inactive route (marked
as unreachable, but still in the routing table), it doesn't go into the OSPF
LSA.  I don't see how it would hurt anything.  A traceroute to that subnet
egresses through the default gateway and other routers don't see a route to
it.  This is ROS 6.44.6 that I'm playing with.  Maybe you've come across a
bug in the version you have?

 

Disabling the interface removes it from the routing table, so I wonder if
disabling unused interfaces would have prevented it.    

 

-Adam

 

From: AF <af-boun...@af.afmug.com> On Behalf Of Nate Burke
Sent: Tuesday, December 06, 2022 1:28 PM
To: AnimalFarm Microwave Users Group <af@af.afmug.com>
Subject: Re: [AFMUG] OSPF Pulling my hair out - SOLVED

 

I think I finally tracked this one down. 

An IP Address out of the /30 that was the OSPF Network was defined on
another Router on an interface in the DOWN state.  So the subnet/IP did not
show up in the routing table, or the OSPF Routing table, or even that local
routers routing table, but it must have caused some conflict in the OSPF
Process.  Disabling the address on the remote router fixed the route
flapping.  It was just causing Routes to change, the OSPF Neighbor never
flapped.    

Found it purely by accident, not sure how I'd have tracked it down otherwise
since there was no route to the subnet and looked like it did not exist
since the interface it was assigned to was down.  

On 10/12/2022 9:04 AM, castarritt wrote:

I made an IP conflict recently after goofing my documentation on a /28 and
overlapping part of it with a /30 on the same router.  It caused the same
sort of problem you were having.

 

On Wed, Oct 12, 2022 at 8:47 AM Nate Burke <n...@blastcomm.com
<mailto:n...@blastcomm.com> > wrote:

I changed the /30 that the OSPF network was using over the F425 and that 
seems to have fixed it.  The original /30 does not exist anywhere else 
on the network that I can find, either as a route, defined IP,  or a 
Router ID.  I didn't think of changing that since it seemed to be a 
weather event that triggered it in the first place, and it had been 
working fine for months.

On 10/12/2022 7:11 AM, Dennis Burgess wrote:
> I would have to take a look, but sounds like duplicate routerID or BFD.
OSPF is pretty straight forward on this.
>
>
>
> Dennis Burgess, Mikrotik Certified Trainer
> MTCNA, MTCRE, MTCWE, MTCTCE, MTCINE, MTCSE, HE IPv6 Sage, Cambium ePMP
Certified
> Author of "Learn RouterOS- Second Edition"
> Link Technologies, Inc -- Mikrotik & WISP Support Services
> Office: 314-735-0270  Website: http://www.linktechs.net
> Need to Automate MikroTik Backups:  https://cloud.linktechs.net
> Create Wireless Coverage's with www.towercoverage.com
<http://www.towercoverage.com> 
>
> -----Original Message-----
> From: AF <af-boun...@af.afmug.com <mailto:af-boun...@af.afmug.com> > On
Behalf Of Nate Burke
> Sent: Tuesday, October 11, 2022 5:18 PM
> To: AnimalFarm Microwave Users Group <af@af.afmug.com
<mailto:af@af.afmug.com> >
> Subject: Re: [AFMUG] OSPF Pulling my hair out
>
> I changed the RB4011 to a RB2009, and tried downgrading the RB4011 to
> ROS6.49.6 from ROS7.5 and it's doing the exact same thing.  I've tried
setting up an EoIP Tunnel across the F425, and changed the Router ID in
OSPF.  Still doing the exact same thing.  As soon as I enable the F425 link,
the Entire route table will flap between the Powerbridge and the
> F425 even though the powerbridge is a cost of 20 higher than the F425.
> If I disable the F425, everything is stable over the Powerbridge.  Not
sure what else to try.
>
> On 10/6/2022 4:22 PM, Robert Haas wrote:
>> Make sure you haven't duplicated your router id.
>>
>>
>>
>> -----Original Message-----
>> From: AF <af-boun...@af.afmug.com <mailto:af-boun...@af.afmug.com> > On
Behalf Of Nate Burke
>> Sent: Tuesday, October 4, 2022 1:58 PM
>> To: AnimalFarm Microwave Users Group <af@af.afmug.com
<mailto:af@af.afmug.com> >
>> Subject: [AFMUG] OSPF Pulling my hair out
>>
>> I have a site with a RB4011 connected via an old M5 Powerbridge, and an
EPMP PTP425.  The 4011 is running ROSv7, everything else is on ROSv6.
Connecting to a CCR1036 and CCR1009 on the other ends of the radios.
>>
>> Everything was working perfectly for several months until a storm came
>> through, and now the F425 OSPF Session will not stay stable. The OSPF
>> Weights are set to prefer the F425 link.  The OSPF neighbor never goes
>> down, Adjacency/state never change, but the RB4011 will update it's
>> entire routing table about every 5 seconds and flap back and forth
>> between the Powerbridge and the F425.  The remote routers never update
>> the route to the 4011, it is stable over the F425.  If I disable the
>> F425 neighbor, everything is stable over the powerbridge.  If I disable
the Powerbridge neighbor, the router will lose connectivity for a second
every 10 or 15 seconds, like it loses it's routing table.
>>
>> There is no packet loss across the F425 link, and it will Tik to Tik bw
test at 100MB sync no problem and no packet loss.  I've even tried changing
ports on the 4011, plugging the F425 into a completely separate OSPF router
on the remote end.  I've also put the traffic through a VLAN on the F425 to
see if the F425 was doing something weird with the packets.  The F425 radios
on both ends have been power cycled.  I've also updated ROS to the latest
7beta, and no change.
>>
>> I'd think this is an issue with ROSv7/6 since the routing table keeps
updating, but the powerbridge link is always fine, so it feels like
something with the F425.  Especially since it happened after a storm.
>> But at the same time, how could a failure of the F425 be affecting OSPF?
When I do OSPF Logging on the 4011, nothing is looking out of the ordinary.
I guess I could try physically changing the 4011, but I've never had a
failure like that before.
>>
>> Mainly I just want to vent that I'm probably missing something stupid, I
just haven't been able to figure out what it is yet.
>>
>>
>
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