[SR-Users] kamailio doesn't reply on internal interface

Hello, we have interesting issue... Some time kamailio comes unreachable on private interface for asterisk, but port checked via telnet and everything is ok... ps. connection via public ip works good root@kamailio:/usr/local/etc/kamailio# lsof -i :5068 | grep LISTEN kamailio 6014 root 13u IPv4 8341589 0t0 TCP kamailio.local.ip:5068 (LISTEN) kamailio 6014 root 14u IPv4 8341590 0t0 TCP kamailio.public.ip:5068 (LISTEN) root@kamailio:/usr/local/etc/kamailio# telnet from asterisk machine: root@asterisk:/etc/asterisk# telnet kamailio.local.ip 5068 Trying kamailio.local.ip... Connected to kamailio.local.ip. Escape character is '^]'. But peer is unreachable in asterisk... More than, kamailio comes reachable when I change transport from TCP to UDP, or when I restart kamailio daemon(but it situation repeats every day).. Any ideas how I can fix it? thanks!