dd if=/dev/zero of=your.big.file bs=1MB count=500

This will create a 500Mb file in your current directory called  your.big.file

500+0 records in
500+0 records out
500000000 bytes (500 MB) copied, 4.08855 seconds, 122 MB/s

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Add this code into your .htaccess file.

<Files ~ "\.tpl$">
Order allow,deny
Deny from all
</Files>

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Theres a lot of work before it goes in. Etch primering, painting laquering and a bit of seem welding.

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A client of mine recently deleted a Windows Server running DHCP and couldn't authorise the new server of the same name.
This is because the client did not Unauthorise the server beforehand. Possibly because the server hardware was dead.

You could get error

The specified servers are already present in the Directory Service

Or this error

DHCP Server not authorized:
Error:
Event ID: 1051
Source: DHCPServer
The DHCP/BINL service has determined that it is not authorized to service clients on this network for the Windows domain: Your_Domain_Name.Domain_Root

Here's a fool proof, yet risky method of sorting the issue out.

1. Open Active Directory Sites and Services.
2. Click Services, and then click Net Services. If you can't see Services, click to select Show Services Node on the View menu.
3. In the right pane, right-click the name of the DHCP servers that you cannot add to Active Directory, and then click Delete.
4. Force replication of Active Directory to the other sites, or wait for the replication cycle to be completed.

Now break out AdsiEdit, my favourite tool.

1. Run AdsiEdit (You may need to install the Windows 2003 Server Support Tools if you're an AdsiEdit virgin).
2. Its best practise to run it on a Global Catalog server.
3. Expand Configuration, expand CN=Configuration, expand CN=Services, and then click CN=NetServices.
4. Right-click CN=Your_DHCP_Root, and then click Properties.
5. In the Select a property to view list, click DHCPServers.
6. In the Values list, click the name of the new DHCP server, click Remove, and then click OK.
7. Click CN=NetServices, right-click the entry for the new DHCP server, and then click Delete.
8. Force replication of Active Directory to the other sites, or wait for the replication cycle to be completed.
9. Reboot the new server. Yeah -  you have to reboot.
10. Attempt to authorise the server again.

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1. Open Active Directory Sites and Services.
2. In the console tree, expand Sites, and then expand the site to which you want to force replication from the updated server.
3. Expand the Servers container to display the list of servers that are currently configured for that site.
4. Expand the server objects and click their NTDS Settings objects to display their connection objects in the details pane. Find a server that has a connection object from the server on which you made the updates.
5. Click NTDS Settings below the server object. In the details pane, right-click the connection object whose From Server is the domain controller that has the updates that you want to replicate, and then click Replicate Now.
6. When the Replicate Now message box appears, review the information, and then click OK.

That is all!

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cd /home && wget -N http://httpupdate.cpanel.net/latest && sh latest && /usr/local/cpanel/cpkeyclt

Go have your lunch. Maybe lunch +VAT depending on the speed of your server.

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[mysqld] skip-innodb

Thats it. One line. Its rubbish.

Here's mine to help you along the way. Its got some decent logging set, some decent cache and memory options for a shared server set and some helpful security settings enabled.

[mysqld]
max_connections = 200
bind-address = 127.0.0.1
 
safe-show-database
skip-locking
skip-innodb
 
# MySQL 4.x has query caching available.
# Enable it for vast improvement and it may be all you need to tweak.
query_cache_type=1
query_cache_limit=1M
query_cache_size=32M
 
interactive_timeout=100
 
# Reduced wait_timeout to prevent idle clients holding connections.
wait_timeout=15
connect_timeout=10
 
# Checked opened tables and adjusted accordingly after running for a while.
table_cache=512
 
# Reduced it to 32 to prevent memory hogging.
thread_cache=32
 
# Reduced it by checking current size of *.MYI files.
key_buffer=128M
 
thread_concurrency=1
 
log_error                = /var/log/mysql/error.log
 
# log slow queries is a must.
log_slow_queries=/var/log/mysqld.slow.log
long_query_time=2
 
[mysqldump]
quick
max_allowed_packet=16M
 
[mysql]
no-auto-rehash
 
[isamchk]
key_buffer=64M
sort_buffer=64M
read_buffer=16M
write_buffer=16M
 
[myisamchk]
key_buffer=64M
sort_buffer=64M
read_buffer=16M
write_buffer=16M
 
[mysqlhotcopy]
interactive-timeout

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SSH - Introducing BFD

BFD is a modular shell script for parsing application logs and checking for authentication failures. In it's simplest form BFD will monitor your SSH log files for potential attacks and take preventative action.

wget http://www.rfxn.com/downloads/bfd-current.tar.gz
tar zxpfv bfd-current.tar.gz
cd bfd-1.4/
sh install.sh

Thats it. The default options are perfect to use with APF. It will block an attackers IP after 15 incorrect login attempts.
Feel free to edit the config file if you want your Inbox full of emails telling you its blocked someone. Trust me, you'll get fed up of it in 15 minutes.

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Here's how I configure it for all the WHM/cPanel boxes I commission, although you can configure it for non-cPanel servers, just adjust your ports accordingly.

wget http://www.rfxn.com/downloads/apf-current.tar.gz
tar zxpfv apf-current.tar.gz
cd apf-9.7-1/
sh install.sh
nano /etc/apf/conf.apf

These are the main settings I change in the configuration file.

# !!! Do not leave set to (1) !!!
# When set to enabled; 5 minute cronjob is set to stop the firewall. Set
# this off (0) when firewall is determined to be operating as desired.
DEVEL_MODE="0"
 
# Common ingress (inbound) TCP ports for cPanel & WHM
IG_TCP_CPORTS=" 20,21,22,25,26,53,80,110,143,443,465,993,995,2077,2078,2082,
2083,2086,2087,2095,2096,3306,6666"
 
# Common ingress (inbound) UDP ports for cPanel & WHM
IG_UDP_CPORTS="21,53,465,873,2077,2078"
 
# Common ICMP (inbound) types
# 'internals/icmp.types' for type definition; 'all' is wildcard for any
IG_ICMP_TYPES="3,5,11,0,30,8"
 
# Outbound (egress) filtering - Always a good idea.
EGF="1"
 
# Common egress (outbound) TCP ports for cPanel & WHM
EG_TCP_CPORTS="21,25,26,37,43,53,80,113,465,873,3306"
 
# Common egress (outbound) UDP ports for cPanel & WHM
EG_UDP_CPORTS="20,21,53,465,873"
 
# Common ICMP (outbound) types
# 'internals/icmp.types' for type definition; 'all' is wildcard for any
EG_ICMP_TYPES="all"

One final setting I had to change was the BLK_RESNET option

Block all ipv4 address space marked reserved for future use (unassigned),
# such networks have no business talking on the Internet. However they may at
# some point become live address space. The USE_RD option further in this file
# allows for dynamic updating of this list on every full restart of APF. Refer
# to the 'internals/reserved.networks' file for listing of address space.
BLK_RESNET="0"

Then, finally, start it /etc/init.d/apf start

You can confirm it is working with iptables -L

These are the Inbound tcp/udp and Outbound tcp/udp ports in question

Inbound TCP Ports

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