{"id":1927,"date":"2012-11-17T11:35:18","date_gmt":"2012-11-17T11:35:18","guid":{"rendered":"http:\/\/mccltd.net\/blog\/?p=1927"},"modified":"2013-11-17T11:38:01","modified_gmt":"2013-11-17T11:38:01","slug":"linux-command-primer-aide-memoir","status":"publish","type":"post","link":"http:\/\/darenmatthews.com\/blog\/?p=1927","title":{"rendered":"Linux Command – Primer \/ Aide-Memoir"},"content":{"rendered":"

System Shut Down<\/strong>
\nshutdown -h now (Displays the file hello.txt)
\nshutdown -h +15 (Displays the file hello.txt)
\nshutdown -r now (Shut Down > Restart now)
\nshutdown -r +15 (Shut Down > Restart in 15 minutes)<\/p>\n

IP Configuration<\/strong> (Edit the ifcfg-eth0 file):
\ncat \/etc\/sysconfig\/network-scripts\/ifcfg-eth0 \u00a0\u00a0 \u00a0View the configuration file for eth0
\nvi \/etc\/sysconfig\/network-scripts\/ifcfg-eth0 \u00a0\u00a0 \u00a0Edit and Save the configuration file for eth0<\/p>\n

DEVICE=eth0
\nBOOTPROTO=static
\nBROADCAST=10.10.255.255
\nHWADDR=00:13:72:3E:55:72
\nIPADDR=10.10.0.1
\nNETMASK=255.255.0.0
\nNETWORK=10.10.0.0
\nDNS1=4.2.2.2
\nDNS2=8.8.8.8
\nONBOOT=yes
\nTYPE=Ethernet<\/p>\n

Enter new IP information. and save the file.
\nifdown eth0
\nifup eth0 \u00a0\u00a0 \u00a0Restart the eth0 – the new configuration will take effect.<\/p>\n

IP Configuration<\/strong> (Temporarily uses the new IP until the next reboot.)<\/p>\n

ifconfig lo0 localhost up
\nifconfig eth0 inet 192.168.1.1 netmask 255.255.255.0
\nbroadcast 192.168.1.255<\/p>\n

Default Gateway (Temporarily uses the new gateway IP)
\nroute add default gw 192.168.1.1 eth0<\/p>\n

Edit the network file:<\/strong>
\ncat \/etc\/sysconfig\/network \u00a0\u00a0 \u00a0View the Network File
\nvi \/etc\/sysconfig\/network \u00a0\u00a0 \u00a0Edit and Save the Network File<\/p>\n

NETWORKING=yes
\nHOSTNAME=server20.comentum.com
\nGATEWAY=192.168.1.1 \u00a0\u00a0 \u00a0(Type in the new gateway and host information. and save the file)<\/p>\n

service network restart\u00a0 (Restart the network services)<\/p>\n

Domain Name Servers<\/strong><\/p>\n

Edit the \/etc\/resolv.conf file:
\ncat \/etc\/resolv.conf \u00a0\u00a0 \u00a0View the resolv.conf File
\nvi \/etc\/resolv.conf \u00a0\u00a0 \u00a0Edit and Save the resolv.conf File<\/p>\n

search darenmatthews.com
\nnameserver 66.28.0.45
\nnameserver 206.13.28.11
\nnameserver 67.17.215.132<\/p>\n

Firewall with Editing iptables<\/strong>:
\niptables -L\u00a0 (View the current firewall configuration)
\ncat \/etc\/sysconfig\/iptables (View\/read the real firewall file)<\/p>\n

Edit the iptables file:
\nvi \/etc\/sysconfig\/iptables \u00a0\u00a0 \u00a0(Edit and Save the firewall iptables file)<\/p>\n

.# This firewall is an example of a Linux web, ftp, pop3 & smtp server
\n.# It also limits ssh access to a block of IP – you need to customize the IPs to match your allowed IPs for ssh access
\n*filter
\n:INPUT ACCEPT [0:0]
\n:FORWARD ACCEPT [0:0]
\n:OUTPUT ACCEPT [131962:7397220]
\n:inputf – [0:0]
\n-A INPUT -j inputf
\n-A FORWARD -j inputf
\n-A inputf -i lo -j ACCEPT
\n-A inputf -m state –state RELATED,ESTABLISHED -j ACCEPT
\n-A inputf -p tcp -m state –state NEW -m tcp –dport 80 -j ACCEPT
\n-A inputf -p tcp -m state –state NEW -m tcp –dport 443 -j ACCEPT
\n-A inputf -p tcp -m state –state NEW -m tcp –dport 21 -j ACCEPT
\n-A inputf -p tcp -m state –state NEW -m tcp –dport 25 -j ACCEPT
\n-A inputf -p tcp -m state –state NEW -m tcp –dport 110 -j ACCEPT
\n-A inputf -s 192.168.1.0\/24 -p tcp -m tcp –dport 22 -j ACCEPT
\n-A inputf -p ipv6-crypt -j ACCEPT
\n-A inputf -p ipv6-auth -j ACCEPT
\n-A inputf -j REJECT –reject-with icmp-host-prohibited
\nCOMMIT
\nshutdown -r now \u00a0\u00a0 \u00a0Restart the server<\/p>\n

Modifying the Current Firewall Setting<\/strong>
\niptables -I inputf 6 -p tcp -m state –state NEW -m tcp –dport 143 -j ACCEPT
\n(Will insert this rule to the line 6 of inputf chain)<\/p>\n

\/sbin\/service iptables save
\n(Will SAVE the iptables with the new rule.)<\/p>\n

Firewall with iptables command Another Version<\/strong>
\niptables -L (View the current firewall configuration)
\ncat \/etc\/sysconfig\/iptables (View\/read the real firewall file)<\/p>\n

Copy IP Table for Backup:
\n##################
\ncp \/etc\/sysconfig\/iptables iptablesbackup<\/p>\n

# Clear all Tables
\n##################
\niptables -F INPUT
\niptables -F OUTPUT
\niptables -F FORWARD<\/p>\n

#Set Default Policy
\n# Be Carefull : This will drop your ssh connection.
\n# This setting needs to be implemented from the machine’s command line.
\n###################
\niptables -P INPUT DROP
\niptables -P OUTPUT ACCEPT
\niptables -P FORWARD DROP<\/p>\n

# Loopback setup
\n################
\niptables -A INPUT -i lo -j ACCEPT<\/p>\n

# Inbound connections
\n# Customize the below based on your needs for example to add POP3\/Port 110 services add:
\n# iptables -A INPUT -p tcp -m state –state NEW -m tcp –dport 110 -j ACCEPT
\n# add the above statement after Port 80 statement.
\n#####################
\niptables -A INPUT -m state –state ESTABLICHED,RELATED -j ACCEPT
\niptables -A INPUT -p tcp -m state –state NEW -m tcp –dport 80 -j ACCEPT
\niptables -A INPUT -p tcp -m state –state NEW -m tcp –dport 443 -j ACCEPT
\niptables -A INPUT -p tcp -m state –state NEW -m tcp –dport 21 -j ACCEPT
\niptables -A INPUT -s 192.168.1.0\/24 -p tcp -m tcp –dport 22 -j ACCEPT
\niptables -A INPUT -j DROP<\/p>\n

# Save the new setting
\n\/sbin\/service iptables save<\/p>\n","protected":false},"excerpt":{"rendered":"

System Shut Down shutdown -h now (Displays the file hello.txt) shutdown -h +15 (Displays the file hello.txt) shutdown -r now (Shut Down > Restart now) shutdown -r +15 (Shut Down > Restart in 15 minutes) IP Configuration (Edit the ifcfg-eth0 file): cat \/etc\/sysconfig\/network-scripts\/ifcfg-eth0 \u00a0\u00a0 \u00a0View the configuration file for eth0 vi \/etc\/sysconfig\/network-scripts\/ifcfg-eth0 \u00a0\u00a0 \u00a0Edit and […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[84],"tags":[4],"_links":{"self":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1927"}],"collection":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1927"}],"version-history":[{"count":1,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1927\/revisions"}],"predecessor-version":[{"id":1928,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1927\/revisions\/1928"}],"wp:attachment":[{"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1927"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1927"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/darenmatthews.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1927"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}