How to block access from certain IPs in IIS – Windows // Crucial Paradigm

Sometimes mod_security rules may cause problems for some sites, and give you 403 access denied messages. To disable mod_security on a single account, and prevent the 403 access denied error messages you can add the following to your .htaccess file:

SecFilterEngine Off

SecFilterScanPOST Off

Tags: security, system administration

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Filed under: Uncategorized by — aaron @ 6:38 pm

February 25, 2008

How to remove a user in Linux

To check if a user exists in Linux, you can go:

1. You want to remove any files owned by that user, so use the following command:

find / -user username

2. Remove all files belonging to the Linux user.

3. Remove the relevant lines from /etc/passwd and /etc/groups

For example:

cat /etc/passwd | grep username

This is the line you would want to remove if you are deleting the user ‘username’: username:x:503:503::/home/username:/bin/bash

Note: In some Linux distributions you can use the command userdel, or deluser

Tags: linux, ssh, system administration

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Filed under: Uncategorized by — aaron @ 5:31 pm

February 25, 2008

cPanel/WHM: quotacheck: Can’t find filesystem to check or filesystem not mounted with quota option.

When you receive this error message in cPanel/WHM:

/scripts/fixquotas
Installing Default Quota Databases…../aquota.user…./quota.user…./backup/aquota.user…./backup/quota.user…./boot/aquota.user…./boot/quota.user…./tmp/aquota.user…./tmp/quota.user…./var/tmp/aquota.user…./var/tmp/quota.user…..Done
Quotas are now on
Updating Quota Files……
quotacheck: Can’t find filesystem to check or filesystem not mounted with quota option.

quotacheck: Can’t find filesystem to check or filesystem not mounted with quota option.

….Done
Unable to read /etc/quota.conf at /scripts/resetquotas line 23.
You can try the following to resolve it:

First make sure you have the usrquota option for your / partition on /etc/fstab and then reboot the server.

If you are still having issues, make sure your kernel supports quotas.

Tags: cpanel, quotas, system administration

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Filed under: Uncategorized by — aaron @ 2:30 am

February 25, 2008

Configuring Network Interfaces on CentOS, Redhat, Fedora Core, and Debian

CentOS/Red Hat/Fedora Core:

The network configuration files are in the folder:
‘/etc/sysconfig/network-scripts’

The files for the interfaces will be ifcfg-eth0, ifcfg-eth1, ifcfg-eth0:0 (if there are sub-interfaces)

Static IP address configuration:
——————–
[root@sXXX network-scripts]# cat ifcfg-eth0
# Intel Corporation 82573L Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=static
HWADDR=YY:YY:YY:YY:YY
BROADCAST=XXX.XXX.XXX.XXX – specify the broadcast address here
IPADDR=xx.xx.xx.xx – specify the IP address here
NETMASK=255.255.255.0 – specify the netmask here
ONBOOT=yes
TYPE=Ethernet
———————-

Please specify ‘ONBOOT=yes’ which will activate the interface upon system boot

Dynamic IP address configuration: Change BOOTPROTO value to dhcp
——————–
[root@sXXX network-scripts]# cat ifcfg-eth0
# Intel Corporation 82573L Gigabit Ethernet Controller
DEVICE=eth0
BOOTPROTO=dhcp
ONBOOT=yes
TYPE=Ethernet
———————-

To bind a range of IP address, create a file called ifcfg-eth0-range0 (for example eth0:0, eth0:1, etc)

The entries should be:

——————————-
IPADDR_START=192.168.0.10
IPADDR_END=192.168.0.20
CLONENUM_START=0
NETMASK=xxx.xxx.xxx.xxx
——————————–

IPADDR_START: This is the first IP from the address range you want to bind to your ethernet device.
IPADDR_END: This is the last IP from that address range.
CLONENUM_START: This is the number that will be assigned to the first IP alias interface. For instance, if your Internet interface is eth0 and CLONENUM_START is 0, then this config file will create 10 interfaces starting with eth0:0 (eth0:0, eth0:1, eth0:2 etc) and ending with eth0:10.

The gateway for the network can be specified in the file ‘/etc/sysconfig/network’
——————————-
NETWORKING=yes
HOSTNAME=hostname
GATEWAY=”XXX.XXX.XXX.YYY”
———————————
Once you assign the IP addresses and configure the gateway please restart the service network ‘/etc/init.d/network restart’

You may also use ‘/usr/sbin/system-config-network-tui’ to configure the network interfaces

Debian:
In Debian the interface configuration file is ‘/etc/network/interfaces’

The entires are:
———————————
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static
address xxx.xxx.xxx.xxx
netmask yyy.yyy.yyy.yyy
broadcast xxx.xxx.xxx.xxy
network xxx.xxx.xxx.xxz
gateway xxx.xxx.xxx.xxw
———————————

After you configure the network interfaces restart the network service using ‘/etc/init.d/networking restart’

Tags: centos, debian, fedora core, networking, system administration

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Filed under: Uncategorized by — aaron @ 12:01 am