Chih - Wei Yu [ MTN - Innovation Centre ] writes: > > but i get error indicating invalid arguments. > > $$$Correct; the system doesn't allow you to do that. It won't let you > set the MTU $$$greater than ill_max_frag, which is hard-coded to > IP_LOOPBACK_MTU (8192) for lo0. > > >>>>>>>>So there's no way to increase it higher.
Correct. > $$$How have you determined that the default MTU setting on the lo0 > interface is in $$$fact the problem in this instance? > > >>>>Well, it's a hunch. I increased receive and buffer sizes on both > ends and try to push the rate higher. After a couple of minutes, the TCP > connection gets blocked and one of the ends get block in sending state. > Doing a netstat on the loopback, I can see that there are packets > initially but then once its gets blocked, there are no packets between > both ends. Even when I increased the rate, I see roughly the same size > of bytes being relayed between both ends (netstat -I lo0 1, roughly > 8800~9000 packets every second). It sounds to me like you've run into a bug of some sort, not a tuning issue. The system shouldn't need to be tuned for local traffic ... or, really, any traffic. I suggest that you work with Sun's support group to find and fix the root cause of the problem you're seeing. > >>>>>On Linux, I was able to set the MTU value on the loopback much > higher but then again, I didn't run the test through the Linux machine. I don't think that modifying the loopback MTU is the right approach here. It's important to understand that when you're using loopback traffic, the system connects the endpoints directly together. The "MTU" has little to do with how it works and shouldn't be harming performance. -- James Carlson, Solaris Networking <[EMAIL PROTECTED]> Sun Microsystems / 35 Network Drive 71.232W Vox +1 781 442 2084 MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677 _______________________________________________ networking-discuss mailing list [email protected]
