안녕하세요. 초보어드민입니다.
다름이 아니오라 portsentry를 설치해서 확인해 본 결과
이렇게 나오더군요
 [root@test/root]#  grep portsentry /var/log/messages
Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: UDP scan from host: 211.58.253.131/211.58.253.131 to UDP port: 161
Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: Host 211.58.253.131 has been blocked via wrappers with string: "ALL:
211.58.253." Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: UDP scan from host: 211.58.253.131/211.58.253.131 to UDP
 port: 161 Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: Host:211.58.253.131/211.58.253.131 is already blocked Ign
oring Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: UDP scan from host: 211.58.253.131/211.58.253.131 to UDP port: 
161 Mar 13 01:44:49 ad7 portsentry[5948]: attackalert: Host:211.58.253.131/211.58.253.131 is already blocked Ignoring
Mar 13 06:49:37 ad7 portsentry[5936]: attackalert: SYN/Normal scan from host: islandsuncom.net/208.63.44.69 to TCP port:
 111 Mar 13 06:49:37 ad7 portsentry[5936]: attackalert: Host 208.63.44.69 has been blocked via wrappers with string: "AL
L: 208.63.44.69"   [root@test/root]# cat portsentry.history
984388448 - 03/12/2001 18:14:08 Host:203.245.15.3/203.245.15.3 Port: 31337 UDP Blocked
984415489 - 03/13/2001 01:44:49 Host:211.58.253.131/211.58.253.131 Port:161 UDP Blocked
984433777 - 03/13/2001 06:49:37 Host: islandsuncom.net/208.63.44.69 Port:111 TCP Blocked
 일단 /etc/services 포트를 막았습니다.
#snmp           161/udp
#sunrpc         111/tcp         portmapper      # RPC 4.0 portmapper TCP
#sunrpc         111/udp         portmapper      # RPC 4.0 portmapper UDP
 그리고 기본적으로 Tcp Wapper  hosts.deny를 ALL:ALL로설정했으니
ALL:211.58.253.131....이렇게 portsentry가 등록을 시켜놔도
아무런 효과가 없을 듯한데...
 아님...고수님들이 아시는 특단(?)의 조치는 없을까요?--이 곳에 서명을 적어주십시오.
끝까지 읽어주셔서 감사합니다.^^