[j-nsp] MTU mismatch between EX4200 and EX4500 / OSPF3 adjacencies

[Michael Loftis]

I've learned to configure MTU explicitly everywhere in Juniper.  Too
many places where they're getting it wrong.  Setting vlan-tagging will
usually get the right setting but interface-mode or port-mode trunk
links can come up with wrong MTUs...

http://kb.juniper.net/InfoCenter/index?page=content&id=KB25421

On Mon, Mar 2, 2015 at 9:56 AM, Chuck Anderson <cra at wpi.edu> wrote:
> On Mon, Mar 02, 2015 at 06:05:18PM +0100, Laurent CARON wrote:
>> We clearly see a MTU mismatch (1500 vs 150*4* for inet6 on the 4200
>> side) leading to OSPF adjacencies not coming up.
>>
>> Setting:
>> set interfaces ae26 mtu 1518
>> on the 4200 side allows to have the OSPF adjacencies up.
>>
>> Did you guys experience such bahavior ?
>>
>> 4200 are running 12.3R8.7
>> 4500 is running 12.3R7.7
>
> I do not have an answer to your question, but this is one reason I
> always configure family inet mtu 1500 and family inet6 mtu 1500.  Then
> you can set the physical mtu as high as you want to accomodate
> multiple VLAN tags, MPLS, etc. without worrying.
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp



-- 

"Genius might be described as a supreme capacity for getting its possessors
into trouble of all kinds."
-- Samuel Butler