Make sure it's not broadcast ospf, I believe that's the default. If one
side flaps it goes away til the other side either reboots or ospf
disables/enables

On Jul 5, 2017 11:25 PM, "George Skorup" <[email protected]> wrote:

> No, not the L2 MTU. The L3 (IP) MTUs must match on the router interfaces
> speaking OSPF.
>
> I have zero experience with SIAE gear, but being a licensed radio, I
> imagine it has an integrated ethernet switch. I've seen a fair number of
> switches go stupid. If you can run 1500 byte pings across the link with no
> loss, then I'd assume both L2 and L3 should work as expected. However, that
> doesn't mean something isn't screwing with multicast, which OSPF obviously
> needs.
>
> On 7/5/2017 10:15 PM, Jason McKemie wrote:
>
> I checked, all MTUs on these links are the same.  The L2 MTU, however, is
> not.  Does this have any effect?
>
> On Wed, Jul 5, 2017 at 10:12 PM, Jason McKemie <
> [email protected]> wrote:
>
>> No errors or packet loss.  Strangely, it seems to be preferring the
>> Rocket M5 backhaul over the SIAE 11GHz link.  The MTU on both ends of the
>> link has remained at default on these.  I'll double check, but unless it
>> changed itself it should be the same.
>>
>> On Wed, Jul 5, 2017 at 8:13 PM, George Skorup <[email protected]>
>> wrote:
>>
>>> Errors or packet loss? Something rate limiting multicast? Has someone
>>> recently changed MTUs? I don't know if RouterOS will even log OSPF MTU
>>> mismatches. Never tried it. If the IP/L3 MTUs don't match, then OSPF is not
>>> gonna have a good time. OSPF relies on IP since there is no native
>>> fragmentation in the protocol.
>>>
>>> As far as NTP and/or accurate time, I haven't experienced any issues
>>> with that in regards to OSPF. I discovered a router where the NTP process
>>> appeared to have crashed and the clock was off by like 10 minutes. OSPF was
>>> humming along with two neighbors for months and a third for hours because
>>> the adjacent router was rebooted.
>>>
>>> On 7/5/2017 7:20 PM, Darin Steffl wrote:
>>>
>>> I also recommend only using bug fix release for mikrotik. Also make sure
>>> you have clocks synced to an ntp source on every mikrotik router and that
>>> it's accurate.
>>>
>>> On Wed, Jul 5, 2017 at 7:09 PM Jason McKemie <
>>> [email protected]> wrote:
>>>
>>>> Thanks.  I'll try 6.38.7 tonight.
>>>>
>>>> There haven't been many changes to the network, and every is pingable.
>>>> I did add one static route for a Baicells eNB a week or two ago, but the
>>>> problem cropped up more recently.  I'll have to look into that a bit more.
>>>>
>>>> On Wed, Jul 5, 2017 at 6:59 PM, Chris Wright <[email protected]>
>>>> wrote:
>>>>
>>>>> I recommend sticking to the Bugfix releases (currently 6.38.7).
>>>>>
>>>>>
>>>>>
>>>>> Did anything happen recently that could possibly have provoked the
>>>>> disappearance like a VLAN or other L2/L3 change? Are the neighbors 
>>>>> pingable
>>>>> on their backbone IPs?
>>>>>
>>>>>
>>>>>
>>>>> Chris Wright
>>>>>
>>>>> Network Administrator
>>>>>
>>>>>
>>>>>
>>>>> *From:* Af [mailto:[email protected]] *On Behalf Of *Jason McKemie
>>>>> *Sent:* Wednesday, July 05, 2017 4:53 PM
>>>>> *To:* [email protected]
>>>>> *Subject:* [AFMUG] Mikrotik OSPF
>>>>>
>>>>>
>>>>>
>>>>> Has anyone seen issues with Mikrotik OSPF neighbors just disappearing
>>>>> for no apparent reason? All of my links are ok, but I OSPF just isn't
>>>>> picking anything up on one of them. I might try upgrading both of the
>>>>> Mikrotiks involved, this feels like a bug. I have 6.38.5 on one end and
>>>>> 6.38 on the other, both CCR's.
>>>>>
>>>>
>>>> --
>>> Darin Steffl
>>> Minnesota WiFi
>>> www.mnwifi.com
>>> 507-634-WiFi
>>> <http://www.facebook.com/minnesotawifi> Like us on Facebook
>>> <http://www.facebook.com/minnesotawifi>
>>>
>>>
>>>
>>
>
>

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