This right here. There is still a much bigger underlying problem, and putting 
OSPF on the bridge is only a palliative fix.

 

Chris Wright

Network Administrator

 

From: Af [mailto:[email protected]] On Behalf Of Adam Moffett
Sent: Wednesday, July 19, 2017 3:57 PM
To: [email protected]
Subject: Re: [AFMUG] flapping ethernet port ospf workaround

 

OSPF didn't lose the neighbor, but you still want to fix the ethernet issue.

 

One thing that could be an issue is if you want OSPF to fail over to a 
secondary path.  If the interface goes down, then the router knows instantly 
that something is wrong and convergence can start right away.  If the path is 
down while the interface stays up, then the router has to wait for hello 
packets to time out before it's aware of the issue.  

 

The default dead timer is 40 seconds, so the "it's down but I don't know yet" 
condition has to last at least that long before the router takes action.

 

 

------ Original Message ------

From: "Steve Jones" <[email protected]>

To: "[email protected]" <[email protected]>

Sent: 7/19/2017 3:03:11 PM

Subject: Re: [AFMUG] flapping ethernet port ospf workaround

 

if this doesn't harm anything, I'm thinking I may make this the standard, its 
flapped 24 times since I put it in, not a single ospf drop

 

On Wed, Jul 19, 2017 at 1:54 PM, Chris Wright <[email protected]> wrote:

I’ve had to run OSPF on a bridge in a pinch, and so long as you don’t make any 
live changes to the bridge (adding/removing interfaces), the Mikrotik won’t 
mind. Just remember to set your static OSPF interfaces (if you have any) 
accordingly. Same goes for MPLS – LDP Interfaces if you’re using it. If you’re 
thinking it’ll be like this for longer than a week, leave yourself plenty of 
documentation to backtrack properly. Nothing like coming back to it three 
months later and trying to remember what you did!

 

Chris Wright

Network Administrator

 

From: Af [mailto:[email protected]] On Behalf Of Steve Jones
Sent: Wednesday, July 19, 2017 9:21 AM
To: [email protected]
Subject: [AFMUG] flapping ethernet port ospf workaround

 

So ive been dealing with the SAFs and the mikrotiks being uppity with one 
another.

SAF has a gigabit port, but it only offers the option to lock it to 100, not 
gigabit.

so I have the mikrotiks set, just not the otherside, the port still flaps on 
both radios

 

what was happening is everytime it flaps, the interface dropped in ospf and 
went neighbor down, rerouting traffic then coming back up

 

what I did was made a bridge, added that port to it, and put the ospf ip on the 
bridge itself, this allows the port to flap without the ospf interface going 
down until we work throught the issue with SAF

 

I'm wondering if this is causing some other harm having it on the bridge, 
rather than the physical port

 

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