Thanks to all kind & wise persons who helped me to solve the problem. Gateway and DNS addresses were wrong and /etc/hosts.allow as well. I used Rescue disk to reconfigure network because I do not know another way (more convinient) to do that.
With regards, Eugene Sevinian ---------------------------- Cosmic Ray Division Yerevan Phisics Institute Alikhanian's Brothers str.2 375036 Yerevan 36 Armenia URL: http://www.yerphi.am/crd/prs/sevinian.html Phone: 374-2-352041 (YerPhI), 374-2-344873 (aprt.) Fax: 374-2-350030