[j-nsp] MTU Fragmentation

sthaug at nethelp.no sthaug at nethelp.no
Wed Nov 24 09:58:10 EST 2010

> For various reasons, we are going to be faced with some MTU challenges in
> parts of our ongoing Juniper deployments.
> We can obtain an MTU right now around 1480 network wide..  This will be
> resolved in a year or so we hope but we're in the middle of changes...
> My question is the effects of this from an application perspective - we
> understand this may add some overhead for fragment processing.. 

I wouldn't be worried about the actual overhead of *performing* the
fragmentation - at least not on the hardware (M/MX/T) platforms.

I would be greatly worried about all the hosts sending 1500 byte 
packets from behind firewalls that drop ICMP "DF set and fragmentation
needed" packets from your Juniper routers.

In short, I think you're in for some pain...

Steinar Haug, Nethelp consulting, sthaug at nethelp.no

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