can not find server or dns error

manishU

We are using worksitemp 4.1 HFB9 and solaris 10x.Our application is trusted logon enabled also.We are using tomcat. As far as TCP ?IP config is concerned , it is dynamic and fma is using 2637 port.
Our severs are running fine , processes are stable, but sometime it will suddenly give us can not find server or dns error.This problem is getting resolved when we restart the impm and tomcat.I checked logs I'm getting tcp/ip exception and java.net.socket exception.I checked from N/w front and dns server every thing is fine. Suggest me the possible cause and solution of this issues.