Sender ID Framework SPF Record Wizard This four-step wizard will guide you through the process of creating a new SPF record for your DNS domain.  You should add this DNS record to your domain's DNS configuration.   Note that you may need to manually edit the SPF record created by this wizard if you want to use some of the more advance features of the SPF format.  For complete details please refer to the SPF record specification at http://www.microsoft.com/senderid. Step 1 of 4: Identify Your Domain Please enter the domain name for which you want to create a new SPF record (for example: example.com):   " /> www.microsoft.com/mscorp/safety/content/technologies/senderid/wizs/spf_flow.jpg

How does Sender ID Framework work? Sender sends an e-mail to Receiver. Receiver’s inbound e-mail server receives e-mail and calls its Sender ID Framework. The Sender ID Framework looks up the SPF record of the domain that Sender is using for sending the mail. The receiving Mail Transfer Agent (MTA) determines if the outbound Mail Server IP address matches IP addresses that are authorized to send mail for the user.

Accessing cPanel Through A Firewall

There’s been a long-standing issue from a hosting provider’s point of where cPanel runs on abnormal ports, causing users behind firewalls to be unable to access cPanel. At first, there was cpanelproxy.net which offered (at that time) an automated script that users could install on their hosting accounts to route cPanel traffic over port 80. Around the time that cPanel 11 came out, the script no longer worked, and users behind corporate or school firewalls were out of luck.

cPanel 11 introduced its own proxy to allow users to get around firewall restrictions.

To enable this feature without inconveniencing users, check these three options in WHM > Tweak Settings:

Add proxy VirtualHost to httpd.conf to automatically redirect unconfigured cpanel, webmail, webdisk and whm subdomains to the correct port (requires mod_rewrite and mod_proxy)

Automatically create cpanel, webmail, webdisk and whm proxy subdomain DNS entries for new accounts. When this is initially enabled it will add appropriate proxy subdomain DNS entries to all existing accounts. (Use /scripts/proxydomains to reconfigure the DNS entries manually)

Allow users to create cpanel, webmail, webdisk and whm subdomains that override automatically generated proxy subdomains

*Keep in mind that if you’re establishing these settings on an existing server, it’s going to update the zones for each domain on the server and synchronize them out to the DNS cluster. This got us in trouble once, as we had a number of suspended accounts on a server that ended up having their DNS reverted back when the proxy subdomains were updated.

To enable proxydomains for the whole server:

/scripts/proxydomains add

To enable for all domains on one user’s account:

/scripts/proxydomains –user= add

To enable for a single domain:

/scripts/proxydomains –domain= add

To remove proxy domains, use the same commands as above, only use “remove” instead of “add”. From here, you can access the proxy at http://cpanel.domain.com (or webmail/whm, respectively), or access cPanel normally and let it detect whether you are behind a firewall.

Placing /vz partition to external storage (NAS, NFS)

Sometimes it is need to place /vz partition on external storage. How to perform this procedure on Parallels Virtuozzo Containers system?

Here are exact steps:

1. Make sure that external storage is available as device in /dev/ directory (via e.g. NFS or ISCSI layer)

2. Mount this storage under e.g. mount point /vzs using required options and filesystem type:
# mount /dev/ext_storage_dev_name /vzs

3. Stop Virtuozzo:
# service vz stop

4. Copy all content from /vz to /vzs:
# cp -a /vz/* /vzs/

5. Unmount old /vz directory and /vzs directory:
# umount /vz
# umount /vzs

6. Edit in the file /etc/fstab line for /vz entry to mount external storage under /vz mount point.

7. mount /vz again:
# mount /vz

8. Start Virtuozzo:
# service vz start

Changing the GRUB splash image

Usually GRUB image is in 14 cloor with max 640*480 resolution.

1.We have to convert the jpeg image to that format
In Konsole type
#convert -depth 8 -colors 14 resize 640*480 "location of the jpg file" "target"

Eg: #convert -depth 8 -colors 14 resize 640*480 /root/grub/photo.jpg /root/grub/photo.xpm

2.Then we have to compress it.So use gzip.Go to the /root/grub/ dir and type
#gzip photo.xpm
It gives photo.xpm.gz file.

3.Now modify the grub config file
Open grub.conf file in /boot/grub dir
And look for the line 'splashimage='
Here give " splashimage=/root/grub/photo.xpm.gz "

Now reboot the system and see the change.

Executable not set-uid root

One of the servers here at work was giving a 500 Internal Server error whenever a PHP page was loaded. Among the various things that can cause this error when you’re running PHP in CGI mode (suPHP), this error showing up in the Apache log was most unusual. Turns out it’s due to the suphp binary missing its sticky/suid permissions.

SecurityException in Application.cpp:188: Do not have root privileges. Executable not set-uid root?

To fix, simply chmod +s the suphp binary:

chmod +s /opt/suphp/bin/suphp

Setup linux server to alert you on login

To improve the security of a Linux server, especially a web server, which is exposed to the Internet and possible worldwide hackers, it’s best to enable the server to automatically send a notification email to predefined email address anytime someone logs in as root to the host. To configure the automatic email alert notification to a default email address on each incident of root log on on the server, use the following guide.

1. Login to the server via SSH using as root ID.
2. Ensure that you’re at home directory of root. Then open up the .bash_profile for editing using pico or vi by typing one of the following commands at command shell line:

Using Pico# pico .bash_profile
Using Nano# nano .bash_profile
Using Vi# vi .bash_profile

3. Scroll down to the end of the file and add the following line:

“echo ‘ALERT – echo ‘ALERT – Root Shell Access (YourserverName) :’ `date` `who` | mail -s “Alert: Root Access from `who | cut -d”(” -f2 | cut -d”)” -f1`” user@example.com” (Without the quotes)

Now logout and login again as root, you should receive an email alert at your inbox. This works on most popular flavor of Linux such as RedHat, CentOS, Ubuntu, FreeBSD , etc.

4. Replace user@email.com with the actual email account address that you want to the root access alert notification been sent to. Note that you can change the text contains in the email alert too. You will want to change the (YourserverName) to your actual server name or hostname.

Looking for a free server load monitoring utility which will email you about the load on the server on a frequent interval ?

CRONJOB is the Answer …..

create a cronjob from the uptime command if thats all you need.

crontab -e

* */1 * * * (cd /usr/bin; ./uptime 2>&1 | mail -s “System load” your.email.com)

The above example will email the load and uptime to you every hour. “System load” is the email subject and of course change your email to your real address.

You can mail yourself a report the same way with any command you like such as netstat, ps and top or anything you like.