6.2 mtu now limits size of incomming packet

[Artyom Viklenko]

Eli Dart wrote:
> 
> The networks that are apparently working fine are most likely 
> misconfigured, IMHO.
> 
> Others have made a case for permitting an interface to accept as large a 
> packet as it can, regardless of configured MTU.  That's fine for theory.
> 
> My operational experience leads me to a different place.  If an 
> interface receives a packet that is larger than its configured MTU, I 
> would prefer that the packet be dropped as a giant and a giants counter 
>  incremented, regardless of whether the hardware can theoretically 
> receive the packet.  In modern networks, an MTU mismatch within a 
> broadcast domain indicates a broken network, IMHO.  If the devices in 
> the network are configured to enforce MTU for both tx and rx, more 
> problems get spotted during turnup, rather than surfacing later on as 
> difficult-to-diagnose problems that users only call about after they are 
> truly frustrated.  And, if you have a giants counter (or input error 
> counter) you can look at, it makes it straightforward to spot the problem.
> 
> (one could also stretch a bit and say that enforcing MTU on rx might 
> provide less surprise to code that consumes packets and has knowledge of 
> the MTU setting of an interface.....unfortunately I don't know enough 
> about the details of the network stack to know if this is a real concern)

100% agree! :)

-- 
            Sincerely yours,
                             Artyom Viklenko.
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