Sebuah catatan kembali dituliskan.
Ketika seorang kawan bertanya : “carane ndelok ip mana aja sing connect nang centos yak apa?”
Ada sebuah fasilitas dari Centos yang bisa kita gunakan, yaitu menggunakan service netstat.
Dari berbagai sumber didapatkan info mengenai netstat, netstat merupakan command-line tool yang berfungsi untuk melihat koneksi yang masuk dan yang keluar dari server (incoming and outgoing), routing tables, dan statistik dari network interface kita. Dari wikipedia didapatkan info tentang netstat sebagai berikut :
Parameters used with this command must be prefixed with a hyphen (-) rather than a slash (/).
-a : Displays all active TCP connections and the TCP and UDP ports on which the computer is listening.
-b : Displays the binary (executable) program’s name involved in creating each connection or listening port. (Windows XP, 2003 Server and newer Windows operating systems (not Microsoft Windows 2000 or other non-Windows operating systems))
-e : Displays ethernet statistics, such as the number of bytes and packets sent and received. This parameter can be combined with -s.
-f : Displays fully qualified domain names <FQDN> for foreign addresses.(only available on Windows Vista and newer operating systems)
-g : Displays multicast group membership information for both IPv4 and IPv6 (may only be available on newer operating systems)
-i : Displays network interfaces and their statistics (not available under Windows)
-n : Displays active TCP connections, however, addresses and port numbers are expressed numerically and no attempt is made to determine names.
-m : Displays the STREAMS statistics.
-o : Displays active TCP connections and includes the process ID (PID) for each connection. You can find the application based on the PID on the Processes tab in Windows Task Manager. This parameter can be combined with -a, -n, and -p. This parameter is available on Microsoft Windows XP, 2003 Server (and Windows 2000 if a hotfix is applied[2]).
-p Windows and BSD: Protocol : Shows connections for the protocol specified by Protocol. In this case, the Protocol can be tcp, udp, tcpv6, or udpv6. If this parameter is used with -s to display statistics by protocol, Protocol can be tcp, udp, icmp, ip, tcpv6, udpv6, icmpv6, or ipv6.
-p Linux: Process : Show which processes are using which sockets (similar to -b under Windows) (you must be root to do this)
-P Solaris: Protocol : Shows connections for the protocol specified by Protocol. In this case, the Protocol can be ip, ipv6, icmp, icmpv6, igmp, udp, tcp, or rawip.
-r : Displays the contents of the IP routing table. (This is equivalent to the route print command under Windows.)
-s : Displays statistics by protocol. By default, statistics are shown for the TCP, UDP, ICMP, and IP protocols. If the IPv6 protocol for Windows XP is installed, statistics are shown for the TCP over IPv6, UDP over IPv6, ICMPv6, and IPv6 protocols. The -p parameter can be used to specify a set of protocols.
-v : When used in conjunction with -b it will display the sequence of components involved in creating the connection or listening port for all executables.
Interval : Redisplays the selected information every Interval seconds. Press CTRL+C to stop the redisplay. If this parameter is omitted, netstat prints the selected information only once.
-h (unix) /? (windows): Displays help at the command prompt.
Contoh sintak netstat :
To display the statistics for only the TCP or UDP protocols, type one of the following commands:
netstat -sp tcp
netstat -sp udp
untuk melihat port service :
[root@localhost]# netstat -n
Sekian tulisan dari saya, semoga berguna.
Mohon kritik dan saran yang membangun.
Terima Kasih.
