You may want to force bind into full debug mode (the logs get big very quickly so have them on a large disk slice) and also run SAR to log system performance paramiters to show that the system is not being taxed. Solaris also comes with snoop which will let you dump packets so you can see retries and other network issues (and have proof) although I would sugest geting ethereal which can take tcpdump output or live snoops and parse out many protocols and to session level breakdown. You may get it at http://www.ethereal.com/ or there is a Solaris packaged version at www.sunfreeware.com. In any case I expect you really need better proof than the "well they dont start transfers as much as server X,Y,Z do see look at the logs" to prove network issues. Make the local sun guys work and prove to you that it is a network issue, as far as your posts have stated they have yet to...

-Waswas