How to Create Cross-Account Alias Records in AWS Route 53 for an ELB

Managing DNS records across multiple AWS accounts can be challenging, especially when dealing with resources like Elastic Load Balancers (ELBs). If you have a domain hosted in one AWS account and an ELB in another, you might wonder how to create an alias record that links the two. Fortunately, AWS Route 53 supports cross-account alias records, making this process straightforward. Here’s how you can set it up.

Scenario

Account A: Contains the Route 53 hosted zone for your domain.
Account B: Contains the ELB.

Step-by-Step Guide

Step 1: Obtain the ELB DNS NameLog in to AWS Account B.

1. Log in to AWS Account B.
2. Navigate to the EC2 Console: Go to the EC2 dashboard.
3. In the navigation pane, select Load Balancers.
4. Copy the DNS Name of the ELB:Select your target ELB.
5. Note down its DNS name (e.g., my-elb-1234567890.us-west-2.elb.amazonaws.com).

Step 2: Create Alias Record in Route 53

• Log in to AWS Account A.
• Open the Route 53 Console: Go to the Route 53 dashboard.
• Navigate to Hosted Zones and select the hosted zone for your domain.
• Create a New Record:Click on Create Record.
• Choose Simple Routing.
• Configure the Alias Record:Record Name: Leave this blank if you are configuring the zone apex (e.g., example.com), or enter the desired subdomain (e.g., www).
• Record Type: Choose A - IPv4 address.
• Alias: Select Yes.
• Alias Target: Paste the ELB DNS name copied from Account B.
• AWS will automatically resolve the Alias Hosted Zone ID associated with the ELB DNS name.
• Save the Record:Click Create records to save your changes.

Step 3: Verify the Configuration

Check the DNS Record:Use a DNS query tool like dig or nslookup to verify that the domain points to the ELB

dig example.com

The response should include the ELB DNS name.

Updated AWS Documentation

AWS has updated its documentation to clarify the process of creating cross-account alias records. You can refer to the AWS Route 53 Developer Guide for detailed information.
Conclusion

By following these steps, you can successfully create an alias record in AWS Route 53 that points to an ELB in another AWS account. This method ensures seamless integration of your domain with resources across multiple AWS accounts, enhancing your infrastructure’s flexibility and security.

Creating a New ReiserFS Partition for /var on HDD Using GParted: A Step-by-Step Guide

I will walk you through the process of creating a new ReiserFS partition for your /var directory on your hard drive using GParted, and configuring your system to use it. This can help in managing disk space more efficiently and improving system performance.

Step 1: Create a New ReiserFS Partition

Open GParted:Boot into a live session of your preferred Linux distribution and open GParted.
Identify the hard drive where you want to create the new partition (e.g., /dev/sda).


Create the Partition:Select the unallocated space or the partition you want to resize.
Create a new partition and choose "ReiserFS" as the file system.
Label the new partition as "var".

Step 2: Reboot into Emergency Mode

Reboot your system into emergency mode:This can be done by adding systemd.unit=emergency.target to the kernel parameters in your bootloader.


Remount Root as Read-Write:Once in emergency mode, remount the root filesystem as read-write

mount -o remount,rw /

Step 3: Mount the New PartitionMount the new partition to a temporary location

mount /dev/sda8 /mnt/new_var

Step 4: Copy the Existing /var Contents

Copy the contents of /var to the new partition

cd /var cp -Rax * /mnt/new_var/

Move back to the root directory

cd /

Rename the old /var directory

mv var var.old

Unmount the new partition from the temporary location

umount /mnt/new_var

Step 5: Mount the New Partition as /var

Create a new empty /var directory

mkdir /var

Mount the new partition to /var

mount /dev/sda8 /var

Step 6: Update /etc/fstabAdd the new partition to /etc/fstab for automatic mounting on boot:Open /etc/fstab in your preferred text editor

nano /etc/fstab

Add the following line

/dev/sda8 /var reiserfs defaults 0 2

Conclusion

By following these steps, you have successfully created a new ReiserFS partition for your /var directory and configured your system to use it. This process can help improve system performance and manage disk space more efficiently. If you encounter any issues, you can always revert to the old /var by mounting it back from the renamed var.old directory.

Remember to double-check your backups and ensure all critical data is secured before making such changes to your filesystem. Happy partitioning!

How to Install and Configure Linux Socket Monitor (LSM) for Network and Inter-Process Monitoring

Linux Socket Monitor (LSM) is a powerful tool designed to monitor changes to ports and sockets, including both network and inter-process communication (IPC) sockets used between applications on the same machine. By comparing snapshots of socket configurations, LSM provides valuable insights into network activity and facilitates security monitoring. This guide walks you through the process of installing and configuring LSM on your Linux system.

1. Download LSM: Begin by downloading the latest version of LSM from the developer's website. Use the wget command to fetch the tarball

wget http://www.rfxn.com/downloads/lsm-current.tar.gz

2. Extract the Tarball: Once the download is complete, extract the contents of the tarball using the tar command:

tar -xvfz lsm-current.tar.gz

3. Install LSM: Navigate to the extracted directory and run the installation script

cd lsm-0.6 ./install.sh

Upon completion, you will receive a confirmation message displaying installation details and the path to the LSM executable.
4. Configure LSM: Open the LSM configuration file using a text editor (e.g., nano)

nano /usr/local/lsm/conf.lsm

Locate the line with the USER variable and replace the default value (typically "root") with your email address. This allows LSM to send notifications to the specified email address.
Example

USER="your_email@example.com"

Save the changes and exit the text editor.
5. Managing Snapshots: LSM creates snapshots of socket configurations for comparison. You can manage these snapshots using the following commands:Delete snapshots:

/usr/local/sbin/lsm -d
Manually run a comparison test: /usr/local/sbin/lsm -c
Generate base comparison files: /usr/local/sbin/lsm -g

By installing and configuring Linux Socket Monitor (LSM), you gain a powerful tool for monitoring network and inter-process communication on your Linux system. With LSM's ability to track changes to ports and sockets, you can enhance security monitoring and gain valuable insights into network activity.