What to do after Linux Installation

Enable the samba ban: Configure/etc/sysconfig/iptables and enable ports 137, 138, and 139 of the TCP protocol for the eth0 Nic.

# Firewall configuration written by system-config-securitylevel
# Manual customization of this file is not recommended.
* Filter
: Forward accept [0: 0]
: Input accept [0: 0]
: RH-Firewall-1-INPUT-[0: 0]
: Output accept [0: 0]
# Allow Samba to me
-A input-p tcp-m tcp-I eth0 -- dport 137: 139-J accept
-A forward-J RH-Firewall-1-INPUT
-A RH-Firewall-1-INPUT-I lo-J accept
-A RH-Firewall-1-INPUT-p icmp -- ICMP-type any-J accept
-An RH-Firewall-1-INPUT-P 50-J accept
-An RH-Firewall-1-INPUT-P 51-J accept
-A RH-Firewall-1-INPUT-p udp-D 224.0.0.133 -- dport 5353-J accept
-A RH-Firewall-1-INPUT-p udp-m udp -- dport 631-J accept
-A RH-Firewall-1-INPUT-M state -- State established, related-J accept
-A RH-Firewall-1-INPUT-p tcp-M state-m tcp -- dport 22 -- state new-J accept
-A RH-Firewall-1-INPUT-p tcp-M state-m tcp -- dport 80 -- state new-J accept
-A RH-Firewall-1-INPUT-p tcp-M state-m tcp -- dport 21 -- state new-J accept
-A RH-Firewall-1-INPUT-p tcp-M state-m tcp -- dport 25 -- state new-J accept
-A RH-Firewall-1-INPUT-J reject -- reject-with ICMP-host-prohibited
-A input-J RH-Firewall-1-INPUT
Commit
# Generated by Webmin
* Mangle
: Forward accept [0: 0]
: Input accept [0: 0]
: Output accept [0: 0]
: Prerouting accept [0: 0]
: Postrouting accept [0: 0]
Commit
# Completed
# Generated by Webmin
* Nat
: Output accept [0: 0]
: Prerouting accept [0: 0]
: Postrouting accept [0: 0]
Commit
# Completed

If Webmin is installed, you also need to enable TCP port 10000. Note that Rh Linux as4 does not support earlier versions of Webmin. It is tested that Webmin 1.39 can run. It is estimated that earlier versions than 1.39 can be used.

The preceding configuration has enabled ports 80 and 21 of the Web and FTP protocols.

If you do not have any image management tools such as Webmin installed, you must manually edit the iptables file or use the iptables program to complete the operation.

Firewall is an important configuration part in the Linux operating system. Through careful configuration and further program development, you can build a very safe and efficient professional firewall.

Linux also supports rip, OSPF, and other routing protocols. Multiple network adapters can be installed and can be configured as cheap routers.

This article from "100,000 why" Computer Learning Network http://www.why100000.com
Author: Zhang Qing (mesh)