netstat -na | grep 21
结果:
-----------------------------------------------
tcp 0 0 0.0.0.0:21 0.0.0.0:* LISTEN
unix 2 [ ACC ] STREAM LISTENING 8746 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 2 [ ACC ] STREAM LISTENING 9075 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 2 [ ACC ] STREAM LISTENING 9087 /tmp/orbit-root/linc-cbb-0-6474f221c8aa4
unix 3 [ ] STREAM CONNECTED 9815 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9641 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9607 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9599 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9591 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9581 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9569 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9561 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9531 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9521 /var/run/dbus/system_bus_socket
unix 3 [ ] STREAM CONNECTED 9476 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9469 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9458 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9450 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9429 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9403 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9345 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9321 @/tmp/fam-root-
unix 3 [ ] STREAM CONNECTED 9309 /tmp/orbit-root/linc-cbb-0-6474f221c8aa4
unix 3 [ ] STREAM CONNECTED 9307 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9279 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9107 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9090 /tmp/orbit-root/linc-cbb-0-6474f221c8aa4
unix 3 [ ] STREAM CONNECTED 9086 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9078 /tmp/orbit-root/linc-cb9-0-6474f221bc46c
unix 3 [ ] STREAM CONNECTED 9074 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 9029 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 8978 /tmp/orbit-root/linc-ca3-0-4fd528c789021
unix 3 [ ] STREAM CONNECTED 8935 /tmp/orbit-root/linc-ca3-0-4fd528c789021
iptables-save 结果:
-----------------------------------------------
# Generated by iptables-save v1.3.5 on Thu Jul 5 19:50:39 2007
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [3744:4739369]
:RH-Firewall-1-INPUT - [0:0]
-A INPUT -j RH-Firewall-1-INPUT
-A FORWARD -j RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT -i lo -j ACCEPT
-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT
-A RH-Firewall-1-INPUT -p esp -j ACCEPT
-A RH-Firewall-1-INPUT -p ah -j ACCEPT
-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT
-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT
-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 21 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 23 -j ACCEPT
-A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Thu Jul 5 19:50:39 2007