[EMAIL PROTECTED] writes:
> >In any event, I don't think MTU is at all ambiguous here. It's the IP
> >MTU which happens to be equal to the maximum MAC client SDU on
> >Ethernet. (Well, it needs to be _less_ or equal, but it's almost
> >always equal.)
> >
> >
>
> Ok, well, it seems a little odd to me that we report an IP thing
> amongst a collection of link layer properties. In that case, does
> it even belong here? Why not also present the TCP MSS too?
I hope that was meant as hyperbole. I can't tell.
If you wanted to report it as the maximum service data unit from
network layer client to link layer, in order to be absolutely "pure"
about the terminology, then I guess that'd solve the conflict. It'd
be a big column header, though.
However, I do think that referring to this value using the network
layer's view of the limit is in keeping with standard administrative
practices and would not be in any way confusing.
This is a very different concept from the ifconfig versus dladm issue,
which is what I think has you hung up here. Ifconfig on BSD platforms
refers to the ifnet ("we'd call it 'if' but C isn't PL/1") structure,
which represents a mix of L2 and L3 concepts, and which is used for
non-IP protocols. The same thing isn't true on Solaris, and ifconfig
has _always_ shown the IP view of the universe, not the link layer
view, and has _always_ been IP-only.
Yes, we've driven far out of our way to confuse users -- by allowing
"ether" as a keyword and printing MAC layer addresses and by using the
same name to refer to the driver and IP instances of a given "link."
> A problem I can see is that ifconfig has no way of telling you,
> in this case, what the maximum MTU is for a link, so dladm
> is useful for that...but...I'm still not sure this makes sense.
> This seems like a layer violation...
I don't see the problem.
It'd be nice if ifconfig could report what the maximum settable MTU
might be. That'd probably be pretty helpful. I don't see how that
influences whether dladm should report the datalink layer's maximum
SDU. That's an important property, and remains important even if
you're not using IP (and thus, on Solaris, not using ifconfig).
--
James Carlson, Solaris Networking <[EMAIL PROTECTED]>
Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677
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