On (06/18/07 13:01), Darren.Reed at Sun.COM wrote: >> ... >> 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? > > 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...
See, for example, sys/ethernet.h, particularly the comments around ETHERMTU. AFAIK, existing convention is to enter "9000" in the driver.conf file, and expect to see "9000" in the ifconfig output. By your logic, we should require the driver.conf value to account for header/fcs, and, in the ifconfig output, discount these values again. IMHO that could be even more confusing. --Sowmini
