Desktop – Linux \ Windows – Unable to move Application Windows as Top Bar is not visible

Background

There are so much we do on the computer that we are not even aware how we do it. For example, moving and resizing a screen we know we click on something and start moving things around.

But, when we can not do it, we try to see if there alternatives to the more obvious pathways.

 

Problem

My problem has occurred a couple of times in the last few days. I am moving things out of the way and then all of a sudden, I am unable to to move the Application Screen back to focus.

 

Topbar-Not-ShowingUp

 

In the image pasted above, I am no longer able to move and resize my Chrome Application.

Solution

I googled for ways to move things around, but was unsuccessful at describing the problem appropriately.

The best help came via:

Ask Leo – I can’t see the top of a window so I can’t minimize/maximize or close – what can I do
http://askleo.com/i_cant_see_the_top_of_a_window_so_i_cant_minimize_maximize_or_close_what_can_i_do-2/

 

His advice is that I should invoke the System Menu, via keystrokes; specifically ALT-spacebar.

So went back to the little window that is still visible and click in the client Area; there by making sure that the Application is the Active Window and thus the recipient of any key.

And, then hold down ALT while pressing the space-bar.

SystemMenu-Small

Once we did so, we have a nice system menu that, and I can now access the “Move” option.

I suppose I could have accessed ALT-F7, all this time.

Prior to know, I was using CTRL-Shift-W to close otherwise orphaned Chrome Windows.

Chrome – Keyboard Shortcuts
https://support.google.com/chromebook/answer/183101?hl=en

 

Thanks Leo.

 

 

Technical: DNS – Query for Name Server (NS) – On Linux\CentOS Using Dig

Technical: DNS – Query for Name Server (NS) – On Linux\CentOS Using Dig

 

Install

Install – whois

Install whois:

sudo yum -y install jwhois

 

Install – dig

As Dig is part of the bind-utils, install bind-utils

sudo yum -y install bind-utils

 

 

 

Using Dig

On Linux, we can use dig to query for Name Servers.

Using Dig – Query System’s default Name Server

Syntax:

dig  NS <domain-name> +noall +answer

 

Sample:

dig  NS youtube.com +noall +answer

 

Output:

DigQueryForNameServer

Explanation:

In the example above, we are querying the system’s default Name Server.  And, asking it for the authoritative nameservers for the youtube.com domain.

 

Using Dig – Target specific name server

In case something is wrong with our default named server or our default Named Server has been configured not to forward DNS Queries, we can target another DNS Server.

 

Syntax:

dig  @NS <domain-name> NS +noall +answer

 

Sample:

dig  @68.94.156.1 bbc.co.uk  NS +noall +answer +stats

 

Output:

DigQueryForNameServer- target specific server

 

Explanation:

In the example above, we are specifically targeting an AT&T named server (68.94.156.1) and querying for bbc.co.uk domain NameServers.

We do not really need the stats answer block (Query time, Server, when), but included it so that we can confirm that our result came from the specific server that we requested that it comes from.

To exclude stats data, remove +stats or add nostats.

 

 

Using Dig – Query DNS Server (and got back SERVFAIL)

Using dig, query DNS Server and we are getting back SERVFAIL.

Syntax:

dig  <domain-name> NS

 

Sample:

dig notfullysetup.org NS

 

Output:

Image:

dig -- SERVFAIL

Textual:



[dadeniji@adelia tmp]$ dig NS notfullysetup.org

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> NS 
notfullysetup.org

;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 6679
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;notfullysetup.org. IN NS

;; Query time: 42 msec
;; SERVER: 68.87.66.196#53(68.87.66.196)
;; WHEN: Mon Apr 28 10:23:04 2014
;; MSG SIZE rcvd: 33

[dadeniji@adelia tmp]$ 

 

Explanation:

In the example above, we are querying a DNS Server and getting back an error status, specifically SERVFAIL.

SERVFAIL means that an authoritative server is registered, but it is unreachable or faulty.

 

Using Dig – Query DNS Server tracing delegation path

Using dig, query DNS Server and note the delegation path.

Syntax:

dig  <domain-name> +trace

 

Sample:

dig notfullysetup.com +trace

 

Output:

[dadeniji@adelia tmp]$ dig NS notfullysetup.com +trace

; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.17.rc1.el6_4.6 <<>> NS notfullysetup.org +trace

;; global options: +cmd
. 319385 IN NS h.root-servers.net.
. 319385 IN NS m.root-servers.net.
. 319385 IN NS e.root-servers.net.
. 319385 IN NS i.root-servers.net.
. 319385 IN NS g.root-servers.net.
. 319385 IN NS j.root-servers.net.
. 319385 IN NS a.root-servers.net.
. 319385 IN NS l.root-servers.net.
. 319385 IN NS d.root-servers.net.
. 319385 IN NS b.root-servers.net.
. 319385 IN NS k.root-servers.net.
. 319385 IN NS c.root-servers.net.
. 319385 IN NS f.root-servers.net.
;; Received 496 bytes from 68.87.66.196#53(68.87.66.196) in 727 ms

com. 172800 IN NS k.gtld-servers.net.
com. 172800 IN NS l.gtld-servers.net.
com. 172800 IN NS h.gtld-servers.net.
com. 172800 IN NS g.gtld-servers.net.
com. 172800 IN NS m.gtld-servers.net.
com. 172800 IN NS d.gtld-servers.net.
com. 172800 IN NS j.gtld-servers.net.
com. 172800 IN NS f.gtld-servers.net.
com. 172800 IN NS b.gtld-servers.net.
com. 172800 IN NS i.gtld-servers.net.
com. 172800 IN NS c.gtld-servers.net.
com. 172800 IN NS e.gtld-servers.net.
com. 172800 IN NS a.gtld-servers.net.
;; Received 505 bytes from 2001:7fe::53#53(2001:7fe::53) in 1038 
ms

notfullysetup.com. 172800 IN NS ns1.notfullysetup.com.
notfullysetup.com. 172800 IN NS ns2.notfullysetup.com.

dig: couldn't get address for 'ns1.notfullysetup.com': no more

[dadeniji@adelia tmp]$ 


 

Explanation:

In the case listed above we asked for a trace on what dig did, and it says that the root servers were queried and returned our ns1 and ns2 name servers.

But, we were unable to get the address for ns1.

Upon taking a second look, you might also notice that the first query went to the root servers and we were referred to the gtld-servers.net servers.

Keep in mind that *.gltd-servers.net servers are authoritaive for .com top level domain.

 

Who Is

As one plays more with dig, you might find it important to make sure that your NameServers are properly recorded, as well.

The whois utility provides a nice complement to dig.
Syntax:

whois <domain-name>

 

Sample:

whois wordpress.com | egrep 'Name Server'

 

Output:

whoIs

 

 

Helpful Hints

Helpful Hints – When specifying Name Server

When specifying Name Server using @NS, see if you can use IP Address , as the initial DNS resolution for NS might itself fail.

Helpful Hints – When querying for specific Name, place a period at end of full name

When querying for a specific name, please place a period at end of the name to indicate that the default name (resolv.conf in linux) not be appended to the hostname.

 

References

References – Installation

 

References – DNS Examples

References – DNS TroubleShooting

 

References – DNS TroubleShooting – Trace

 

References – DNS – Q&A

 

 

Technical: Linux – Remote Desktop from Linux to MS Windows ( Using rdesktop )

Technical: Linux – Remote Desktop from Linux to MS Windows ( Using rdesktop )

Background

I need to be able to remotely connect from my Linux\CentOS box to my MS Windows box.

In this post, we will use rdesktop.

 

On Linux box, Install rdesktop

 

Is rdesktop installed

Is rdesktop installed?


rpm -qa | grep -i "rdesktop"

Output:

IsRemoteDesktopInstalled

In our case, we come back with rdesktop-1.7.1-1.el6.i686.  What does that name in terms of versioning:

 

 

Install rdesktop if not installed

Install rdesktop if not installed


sudo yum -y install rdesktop

Output:

yumInstall

On Linux box, Use rdesktop

 

On Linux box, launch rdesktop

Syntax:

rdesktop <hostname>

 

Sample:

rdesktop hrdb

 

On Linux box, enter user’s logon credentials

remoteDesktopLoginScreen

 

 

 

Acknowledgment

Acknowledging Narad Shrestha @ techmint.com as I followed his blog post
( http://www.tecmint.com/how-to-use-rdesktop-in-redhat-centos-fedora/ ).

And, never once did I get lost.

 

Listening

Listening to …

Aloe Blacc – Wake me up

 

References

Technical: Linux\CentOS – Network – Full Qualified Domain Name on Comcast Home Network \ In-house DNS Server

Technical: Linux\CentOS – Network – Full Qualified Domain Name on Comcast Home Network \ In-house DNS Server

Introduction

I have a little home Network behind my Wireless Access Point.  But, lately one of the boxes that I need to access has being up and down.  And, I really need it to be up.

Quick Analysis

I am bit disinclined to do heavy network troubleshooting. I just need need things up; reliably and running.

What is wrong?

  • Is it a Comcast problem; btw Comcast is my ISP
  • Is it just this old LinkSys Home Router – I have it fronting the internal network; acting as a DHCP host, distributing IPs and forwarding network packets based on Port Forwarding – Traffic Cop, the good one – Looks at Port# and sends it over to specific machines
  • Is it my Linux box (CentOS)
  • It it an on \ off again Software Firewall on the Linux box

Usually, it wouldn’t bother me.  But, I really need to learn.

Comcast Network (thinking….)

I know I am entitled to 5 IPs from Comcast; and I have a spare one.

So for this one host that I need to communicate with, I will like to bypass the LinkSys Router and connect directly to the network switch that is connected to the Cable Modem

Comcast Network (Connected)

Once that connection is made, I have a good world reachable IP Address.  Hopefully, it will stay up and available.

Fully Qualified Domain Name

As the host is a box that will be running Hadoop, I know I need really good and firm FQDN.

What is the Network Domain Info

What is Comcast DHCP giving out?

Checked /etc/resolv.conf and have this entries:

Entry Value
domain hsd1.ca.comcast.net
search hsd1.ca.comcast.net
nameserver 75.75.75.75
nameserver 75.75.76.76

What do we want it to be?

I really do not care much about the details.  But, I need to be able to control my destiny; which means having my own domain data:

Here is what we came up with:

Entry Value
domain labdomain.org
search labdomain.org
nameserver 24.6.75.90 (labdomain.org DNS Server)

DNS Server Changes

Create A and “Reverse Lookup” entries for our linux host.

Our DNS Server happens to be a Windows based, and we will just use a GUI to make the changes.

DNS - A Entry

Linux Node DNS Changes

On the linux node, update /etc/resolv.conf with our updated DNS entries.

# Generated by NetworkManager
domain labDomain.org
search labDomain.org
nameserver 24.6.75.90

Explanation:

  • Our domain name is labDomain.org
  • Our DNS Suffix is labDomain.org
  • In our case, as we getting an IP from Comcast and a home grown network domain, we need to ensure that we choose our own DNS Server (that is also reachable over the Net).

Work Arounds

In case you do not have a good DNS Server or limited network addresses, please consider using a third party Dynamic DNS Provider.

My favorite used to be http://dyn.com/dns/, but it seems that they are pulling back on free FQDNs.

Though, I have yet to try noip.com, I have being hearing good things about it.