Tag Archives: DNS

Linux

Eric Hammond: Using An AWS CloudFormation Stack To Allow "-" Instead Of "+" In Gmail Email Addresses

Leave a comment
Launch Stack

Launch a CloudFormation template to set up a stack of AWS resources to fill
a simple need: Supporting Gmail addresses with “-” instead of “+”
separating the user name from the arbitrary tag strings.

The CloudFormation stack launched by the template consists of:

  • ELB (Elastic Load Balancer)
  • Auto Scaling Group
  • EC2 instance(s) running Postfix on Ubuntu set up by a user-data script
  • Security Group allowing ELB to connect to the instances
  • CloudWatch CPU high/low alarms
  • Auto Scaling scale up/down policies.
  • SNS (Simple Notification Service) topic for notification of Auto
    Scaling events
  • Route53 Record Set

This basic stack structure can be used as a solution for a large
number of different needs, but in this example it is set up as an SMTP
email relay that filters and translates email addresses for Google
Apps for Business customers.

Because it uses Auto Scaling, ELB, and Route53, it is scalable and able
to recover from various types of failures.

If you’re in a rush to see code, you can look at the CloudFormation
template and the initialization script run from
the user-data script.

Now, let’s look a bit more in depth at the problem this is solving and
how to set up the solution.

Background

If you have a Gmail address of user@example.com, then email messages
sent to addresses of the form user+ANYTHING@example.com will also be
delivered to you. You can use any email address string after the plus
sign.

Google describes this feature in a blog post:

Append a plus (“+”) sign and any combination of words or numbers
after your email address. For example, if your name was
hikingfan@gmail.com, you could send mail to
hikingfan+friends@gmail.com or hikingfan+mailinglists@gmail.com

This is is useful for tracking where you have entered your email
address and findingout which services allow it to be used for spam.
If an email variation starts getting abused, you can automatically
filter it out in Gmail.

The Problem

Unfortunately, many web sites do not allow an email address with a “+”
when registering and will reject any attempts to use this. I don’t
know if they are trying to prevent people from using unique tracking
addresses or if they just don’t know the specification for a valid
email address, but the end result is the same.

If we could just use a dash (-) instead of a plus, we could enter
unique tracking email addresses in each site registration.

Another example for why plus can be bad: My son added “+psat” to his
email address when filling out the written PSAT so he could track who
they sold his email address to (apparently every college out
there). The data entry person typed a “t” instead of a “+”, so
colleges started sending emails to the wrong address.

Prerequisites

The approach presented here works with custom domains set up with
Google Apps for Business. You can’t use it for individual, free
“@gmail.com” addresses without some additional work and a separate
domain name registration.

As currently written, the CloudFormation stack requires that you
already have your domain DNS handled by Route53, as the template will
insert a new DNS entry for the email relay. This functionality could
be removed from the template if you don’t use Route53.

The Solution

This CloudFormation template sets up a stack that will translate email
addresses when Gmail forwards …read more

Source: FULL ARTICLE at Planet Ubuntu

Linux

Passing regular expression to nawk

Leave a comment

By kchinnam

I am trying to test if I can replace a regular expression in ‘nawk’ with a variable.
Please let me know why it is not working. I am using ksh88i on solaris8
I am trying use this test as a building block to filter active external DNS connections.

Ideally I want to pass variable defined outside nawk as an argument to it.

Code:
# Here I am printing only DNS names.
$> echo server1.domain1.domain2.com | nawk '/^[a-z0-9]*.[a-z0-9]*.[a-z0-9]*.[a-z0-9]*/{print}'
echo server1.domain1.domain2.com

# Here I am trying to pass same pattern a variable, its not working.
$>echo server1.domain1.domain2.com | nawk -v re='^[a-z0-9]*.[a-z0-9]*.[a-z0-9]*.[a-z0-9]*' '/re/{print}'

…read more

Source: FULL ARTICLE at The UNIX and Linux Forums

Linux

Resolv.conf not getting updated regularly!

Leave a comment

By nixhead

Hi All!
I am using Ubuntu 12.04 with LXDE. This is office’s allocated laptop.
I have a problem here now, my /etc/resolv.conf file is not getting updated automatically whenever I am switching network, i.e. home or office. I have to do it manually every-time, I manually input the office’s DNS, when I come to office, or Google’s DNS whenever I log-on to home’s network.
I have reset the resolvconf, but it didn’t help.
Anybody here has any clue about it?

…read more

Source: FULL ARTICLE at The UNIX and Linux Forums

Business, Finance, Occupation & Industry

Westell Announces Homecloud Remote Access

Leave a comment

By Business Wirevia The Motley Fool

Filed under:

Westell Announces Homecloud Remote Access

AURORA, Ill.–(BUSINESS WIRE)– Westell Technologies, Inc. (NAS: WSTL) , a leading provider of telecommunications equipment for wireline, wireless and home networks, today announced the availability of remote access functionality for its HomecloudTM product. The new feature is available in recently released software versions of Homecloud Digital Home Manager along with phone and tablet applications using Apple® iOS and Android operating systems.

“This feature completes the initial set of applications that we had planned for Homecloud,” said Rick Gilbert, Chairman and CEO of Westell Technologies. “It facilitates remote access utilizing dynamic DNS, via any internet connection, to data that is accessible to the Homecloud Digital Home Manager. For example, users can easily access their data that is stored on USB or eSATA drives attached to the DHM. They can also access the data stored at home on Homecloud-enabled computers from virtually anywhere.”

Homecloud effectively networks multiple devices using a variety of operating systems. It significantly simplifies the management and sharing of data and media content, and it allows the user to enjoy the benefits of backup and sharing without the privacy and security concerns or the bandwidth demands that are inherent in cloud-based solutions.

Homecloud units may be purchased only via the Homecloud website, www.homecloud.com, at a price of $180 per unit. Fulfillment is provided by Amazon.


About Westell

Westell Technologies, Inc., headquartered in Aurora, Illinois, designs, distributes, markets and services a broad range of carrier-class communications equipment. This includes digital transmission, intelligent site management, power distribution, demarcation and cell-site optimization products used by wireline and wireless telecommunications service providers, industrial customers, and home network users. For more information, please visit www.westell.com.


“Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995

Certain statements made here that are not historical facts or that contain the words “believe,” “expect,” “intend,” “anticipate,” “estimate,” “may,” “will,” “plan,” “should,” or derivatives of them, and other words of similar meaning, are forward-looking statements that involve risks and uncertainties. Actual results may differ materially from those expressed in or implied by these forward-looking statements. Factors that could cause actual results to differ

From: http://www.dailyfinance.com/2013/04/11/westell-announces-homecloud-remote-access/

Do it yourself

More info on "Black Hole Routers"?

Leave a comment

By rstripe

An earlier thread referred to a test for “black hole routers”….is this something that would only affect ADSL connections? ie., it would not apply to cable internet?

Inasmuch as I am getting slower & slower browsing speed, and more frequent messages saying unable to resolve DNS lookup, (or something to that effect),
I have run this test (tracert) a dozen times or so over the last month, and each time the result shows all asterisks between the 1st & last lines, followed by “timed out” ……

Can I assume that advising AT&T about this condition will fall on deaf ears?

Even us gluttons for punishment have our limits, as I am now paying $98/mo for land line phone & internet, which at last speed test managed 0.45Mbps DL.

Source: DoItYourself.com

Linux

Adding Domain name n resolv.conf file without vi editor

Leave a comment

By karthikk0508

Hi Guys,
I want to add the domain name entry to resolv.conf file. when i use the vi editor to do it the changes are gone after DNS client is being restarted. In Solairs 11 I figured out svccfg command will help to retain the cinfguration. but in linux how do we do that. Also for Solaris are there any additonal steps to be performed like refresh and validate once I change the Domain name. Please help. appreciate your help in advance.
karthik

…read more

Source: FULL ARTICLE at The UNIX and Linux Forums

Linux

Ben Howard: Official Ubuntu Mirrors in HP Cloud

Leave a comment

We are pleased to announce that Canonical has stood up official mirrors in HP Cloud’s AZ-1, 2, and 3 regions.

If you are using Ubuntu Server 12.10 Cloud Images, there is no action to take; 12.10 images are by default configured to use the new mirror address.

For Ubuntu 12.04 instances, the default Ubuntu image does not automatically use the in-HP Cloud mirrors. We are currently working with HP to publish a new image that defaults to the local mirrors. If you would like to switch to the new in-HP mirrors, simply run:
          
    $ sudo sed -i -e
            ‘s,^archive.ubuntu.com/ubuntu,nova.clouds.archive.ubuntu.com/ubuntu,g’ 
             /etc/apt/sources.list 

    $ sudo apt-get -y update

Note: *.clouds.archive.ubuntu.com is configured using split-horizon DNS. This means that the DNS answer to queries is based on the askering IP address; only queries originating within HP Cloud are answered with the HP Cloud mirror addresses. If your DNS resolver[s] is not based in HP Cloud, then you will be unable to benefit from these new mirrors. 
  …read more

Source: FULL ARTICLE at Planet Ubuntu

Linux

Installation problem in Ubuntu

Leave a comment

By toshanshu

File Type: png
ins this a common problem , whenever i try installing a new package or software i usually get this failure msg:

Setting up dsc-statistics-collector (201203250530-1) …
Adding system user
Warning: The home dir /home/Debian-dsc-statistics you specified already exists.
The system user `Debian-dsc-statistics’ already exists. Exiting.
* Starting DNS Statistics Collector (default) dsc-collector * already running! 😮
[fail]
invoke-rc.d: initscript dsc-statistics-collector, action “start” failed.
dpkg: error processing dsc-statistics-collector (–configure):
subprocess installed post-installation script returned error exit status 1
Errors were encountered while processing:

i cant linkup the problem w/o knowledge of DNS static collector and their significance in this context
even googling it doesn’t give satisfactory meaning

i m expecting expert review!
:p

thanks in advance 🙂

…read more
Source: FULL ARTICLE at The UNIX and Linux Forums

Computers

Flaw leaves servers vulnerable to denial-of-service attacks

Leave a comment

A flaw in the widely used BIND DNS (Domain Name System) software can be exploited by remote attackers to crash DNS servers and affect the operation of other programs running on the same machines.

The flaw stems from the way regular expressions are processed by the libdns library that’s part of the BIND software distribution. BIND versions 9.7.x, 9.8.0 up to 9.8.5b1 and 9.9.0 up to 9.9.3b1 for UNIX-like systems are vulnerable, according to a security advisory published Tuesday by the Internet Systems Consortium (ISC), a nonprofit corporation that develops and maintains the software. The Windows versions of BIND are not affected.

BIND is by far the most widely used DNS server software on the Internet. It is the de facto standard DNS software for many UNIX-like systems, including Linux, Solaris, various BSD variants and Mac OS X.

Attack can crash servers

The vulnerability can be exploited by sending specifically crafted requests to vulnerable installations of BIND that would cause the DNS server process—the name daemon, known as “named”—to consume excessive memory resources. This can result in the DNS server process crashing and the operation of other programs being severely affected.

To read this article in full or to leave a comment, please click here

…read more
Source: FULL ARTICLE at PCWorld

Linux

Modprobe prepare new IP address

Leave a comment

By alnhk

Hello,

I m working on virtualization and saved the templates in virtual server. On creating the new Virtual machine or linux system, is there a way where during booting, it should prompt for new IP address, gateway, DNS and hostname?

Or is there any configuration in linux where we can modify booting properties so that it will prompt for new ip address, dns, gateway and hostname?

Thanks in advance.:confused::confused::confused::confused:

…read more
Source: FULL ARTICLE at The UNIX and Linux Forums

Linux

Eric Hammond: Replacing a CloudFront Distribution to "Invalidate" All Objects

Leave a comment

I was chatting with Kevin Boyd (aka Beryllium) on the ##aws Freenode IRC channel about the challenge of invalidating a large number of CloudFront objects (35,000) due to a problem where the cached copies of the objects were out of date and the system had not been designed with versioning in the object path or name.

In addition to the work to perform all of these invalidations (in batches of up to 1,000 in each request with at most 3 request outstanding) there is also the issue of cost. The first thousand CloudFront invalidations are free in a month, but the remainder of the invalidations in this case would cost $170 (at $0.005 for each object).

It occurred to me that one could take advantage of the on-demand nature of AWS by using the following approach:

  1. Create a new CloudFront distribution, set up exactly like the existing distribution (except that the new distribution caches would be empty).

  2. Change the application to point to the new CloudFront distribution domain when referring to the objects.

Step 2 consists of a simple DNS change, assuming that you use your own domain name (e.g., cdn.example.com) when referring to the CloudFront objects in your web site or application, and where that domain name is a CNAME reference to the actual CloudFront distribution.

As soon as this is completed (preferably with a short DNS TTL) then the new CloudFront distribution will be hit by clients and will be filled up with the new versions of the objects.

After a while, you would then destroy and stop paying for the original CloudFront distribution that is no longer being referenced or used.

Simply replacing the CloudFront distribution effectively “invalidates” all of the objects at once, with no charges for invalidation requests and very little effort.

Once again, AWS wins with the principles of on-demand, pay for what you use, throw away what you don’t need.

Original article:
http://alestic.com/2013/03/cloudfront-invalidation

…read more
Source: FULL ARTICLE at Planet Ubuntu

Computers

Google enhances security for your website look-ups

Leave a comment

Google has fully implemented a security feature that ensures a person looking up a website isn’t inadvertently directed to a fake one.

The Internet company has run its own free public Domain Name System (DNS) lookup service, called Public DNS, since 2009. DNS lookups are required to translate a domain name, such as www.idg.com, into an IP address that can be called into a browser.

But DNS systems can be tampered with by hackers. In an attack called “cache poisoning,” a DNS server is hacked and modified so that a user looking for www.idg.com is directed to a different website.

ISPs and other network operators have been slowly implementing DNS Security Extensions (DNSSEC), which use public key cryptography to digitally “sign” the DNS records for websites.

To read this article in full or to leave a comment, please click here

…read more
Source: FULL ARTICLE at PCWorld

Business, Finance, Occupation & Industry

CloudCheckr and UX World Announce Strategic Partnership

Leave a comment

By Business Wirevia The Motley Fool

Filed under:

CloudCheckr and UX World Announce Strategic Partnership

Partnership to include product integration and co-marketing initiatives

ROCHESTER, N.Y.–(BUSINESS WIRE)– CloudCheckr and UX World proudly announce that they have entered into a strategic partnership to deliver customers more effective solutions for optimizing the performance of Amazon Web Services (AWS) cloud infrastructure. The companies will begin joint product development, integrate their technologies, and deliver new capabilities for improving availability and security of cloud infrastructure, which are recognized as major barriers for public cloud adoption.

“CloudCheckr and UX World share a common goal, lowering the barriers to cloud adoption,” said Aaron Newman, CTO and Co-Founder of CloudCheckr. “Our respective solutions both address the complexity of maintaining uptime and enhancing security on cloud infrastructure.”

CloudCheckr monitors the underlying Amazon Web Services resources and configurations to provide visibility into a customer’s AWS security and availability posture that is currently unavailable through native AWS functionality. CloudCheckr users can more tightly manage their AWS infrastructure and policies than simply using the native AWS interface. Its cutting edge analytics provide decision support for managing and scaling AWS deployments while optimally balancing performance, risk and spend.

UX World responds to the cloud-specific problem of impermanent IP addresses for virtual servers, streamlining the process for diagnosing failed cloud servers and rapid re-provisioning. The UX World virtual DNS appliance is the leading solution for maintaining DNS security within the outsourced DNS management environment of cloud computing and invaluable for cloud users. “I am pleased to partner with CloudCheckr. Like us, they recognize the importance of creating cloud-native solutions to solve cloud-unique issues,” said Nick Desai, CEO and Founder of UX World. “We look forward to working with CloudCheckr.”

About CloudCheckr:

CloudCheckr is based in Rochester, NY with satellite office in San Francisco and Argentina. CloudCheckr analytics provide decision support for cloud resource control, purchasing and configurations so companies can scale their cloud infrastructure while balancing performance, security, and spend. It is an Amazon Web Services Technology Partner.

About UX World:

UX WORLD offers a targeted and secure solution to manage DNS and DHCP. This purpose-built application is being offered as a physical device or a virtual appliance. The OVA distribution is compatible with VMware ESXi, CA AppLogic, Xen, and Amazon Web Services. As part of the core functionality, dnslfy resolves a …read more
Source: FULL ARTICLE at DailyFinance

Linux

Solaris 9 – Unable to ping a particular server, traceroute also displays * * *

Leave a comment

By Sanjay255

Hi All,

I am new to solaris environment and we are using Solaris 9

The problem is am unable to ping a particular server from from one of the solaris server

The traceroute also shows only * * * for all the 30 hops

I tried to check all the settings like
1) /etc/hosts -> contains the exact ip of the server to which am trying to ping
2) /etc/resolv.conf -. has the proper DNS
3) /etc/defaultrouter -> has the correct default router assigned
4) No firewall is set

Am able to ping other servers, but only unable to ping/ftp/telnet one and which is very important and necessary for me

Kindly guide me how to resolve the issue

Please let me know if more information is required on this

Thanks in advance for all your valuable suggestion and help

Regards,
Sanjay

…read more
Source: FULL ARTICLE at The UNIX and Linux Forums

Business, Finance, Occupation & Industry

F5 Networks Opens New York International Technology Center

Leave a comment

By Business Wirevia The Motley Fool

Filed under:

F5 Networks Opens New York International Technology Center


Congressman Adam Smith, ranking member of the House Armed Services Committee, and other members of Congress to attend opening and discuss cybersecurity solutions proposed by the President and Congress

NEW YORK–(BUSINESS WIRE)– F5 Networks, Inc. (NASDAQ:FFIV), the global leader in Application Delivery Networking, is proud to announce the March 12 grand opening of its New York International Technology Center (ITC). Located at 600 Lexington Avenue in the heart of Manhattan, this new state-of-the-art application delivery competency center will give engineers, network managers, and technology executives from around the world an opportunity to test networking solutions to ensure their systems are highly resilient and secure.

The announcement of this new ITC comes at a time of high interest in cyber threats for both national defense and in the private sector. During his recent State of the Union address, President Obama noted a new Executive Order on cybersecurity and the advancement of cybersecurity legislation.

“F5 has built its strong brand on the ability to help organizations implement disparate technologies across data centers, networks, applications, and the variety of devices being used,” said Kathleen Ferraro, VP of Product Management and Product Marketing at F5 Networks. “The goal of all our International Technology Centers is to help organizations leverage technology and apply it to the real-world challenges and scenarios they face. For example, we can help a customer architect a single, simplified environment that demonstrates the ways their business is better protected by preventing data leakage and thwarting DDoS strikes, DNS threats, and other attacks.”

The New York ITC grand opening, to be held at 9:00 a.m. ET on Tuesday, March 12, will kick off with a ribbon-cutting ceremony and an overview of the center by F5 CEO John McAdam. Following his address, New York City’s Information Technology and Telecommunications Commissioner Rahul Merchant will speak, followed by Congressman Adam Smith, ranking member of the House Armed Services Committee, and New York Congresswoman Carolyn Maloney. The speakers will address the President’s directive on cybersecurity, among other topics.

“Clearly, technology has become critical to drive businesses and run governments, and it is integral in our personal lives,” said Congressman Adam Smith. “I am proud that F5, a global company headquartered in the Northwest, is taking a leadership role by investing in facilities like …read more
Source: FULL ARTICLE at DailyFinance