Linux

Setup network on Hyper-V virtual CentOS 6

Use system-config-network-tui and set up the card. If you perform a failover, you must connect the card in Hyper-V and then configure the card again.

How to add a route to IPCop

You can add the route command at the end of the /etc/rc.d/rc.local file. The route will be added every time IPCop is rebooted but not everytime the interface is restarted. Good for a box with minimal changes.

root@ipcop: # echo “route add -net 10.10.0.0 gw 10.1.0.1 netmask 255.255.0.0” >> /etc/rc.d/rc.local

SCP files from one linux host to another

su – temp

scp /home/.sites/temp/html/* temp@lamp4.ncol.net:/home/.sites/temp/html/

How to block outgoing SMTP with IPCOP

Edit the /etc/rc.d/rc.firewall.local file and add our new SMTP blocking rules. Open the file with vi or nano, then look for the line “## add your ‘start’ rules here” and put your new rules under it.

 

# allow smtp from some allowed ips
/sbin/iptables -A CUSTOMFORWARD -p tcp -i eth0 -s 10.1.0.6 –dport 25 -j ACCEPT
# log stuff that is not the mail server
/sbin/iptables -A CUSTOMFORWARD -p tcp -i eth0 -s ! 10.1.0.6 –dport 25 -j LOG –log-prefix “SMTP”
# block all other outgoing SMTP traffic
/sbin/iptables -A CUSTOMFORWARD -p tcp -i eth0 -s ! 10.1.0.6 –dport 25 -j REJECT

How to save IPTABLES rules

The following lines allow SMTP and HTTP traffic through an IPTABLES firewall. But this information is not automatically saved and reloaded if the service restarts.

iptables -I INPUT -p tcp –dport 25 -m state –state NEW,ESTABLISHED -j ACCEPT
iptables -I INPUT -p tcp –dport 80 -m state –state NEW,ESTABLISHED -j ACCEPT
iptables-save

Whenever you make a change to your firewall, on a Fedora/CentOS type system, you will want to save the changes.

The output can be redirected to a file.

# iptables-save > /root/firewall-rules
The following command line restores all rules from /root/firewall-rules assuming that the file /root/firewall-rules exists.

# iptables-restore < /root/firewall-rules

By default, iptables-restore deletes all existing rules before restoring the saved rules. If the saved rules are to be appended to existing rules, use the -n or –noflush option.

Save Your Firewall and Load on Restart

You will need to edit the /etc/sysconfig/iptables-config as root to help iptables save and reload your firewall correctly. Be sure the following settings are changed to “yes”.

# Unload modules on restart and stop
# Value: yes|no, default: yes
# This option has to be ‘yes’ to get to a sane state for a firewall
# restart or stop. Only set to ‘no’ if there are problems unloading netfilter
# modules.
IPTABLES_MODULES_UNLOAD=”yes”

# Save current firewall rules on stop.
# Value: yes|no, default: no
# Saves all firewall rules to /etc/sysconfig/iptables if firewall gets stopped
# (e.g. on system shutdown).
IPTABLES_SAVE_ON_STOP=”yes”

# Save current firewall rules on restart.
# Value: yes|no, default: no
# Saves all firewall rules to /etc/sysconfig/iptables if firewall gets
# restarted.
IPTABLES_SAVE_ON_RESTART=”yes”

How to remove password from SSL key

Always backup the original key first (just in case)!

 # cp www.key www.key.orig

Then unencrypt the key with openssl. You’ll need the passphrase for the decryption process:

 # openssl rsa -in www.key -out new.key

Now copy the new.key to the www.key file and you’re done. Next time you restart the web server, it should not prompt you for the passphrase.