martes, 16 de abril de 2013

Network Interface(s) after Linux P2V or V2V conversion | Interface de red de sistemas Linux después de una conversión P2V o V2V

When I started to migrate the systems I manage from a Xenserver environment to a VMWare environment I noticed that all the Linux systems were not able to connect to the network unless I destroyed and recreate the Interface, same happened when importing OVA or OVF templates. Finally I manage to squeeze some time and research about this issue and find a post on Alex Cline's blog where he explains why this happens and also present a more elegant solution rather than my primitive "search & destroy). Below I will summarize the solution, please refer to Alex Cline blog to read the full explanation and details.

When trying to bring up Network Interface the following message appears:

Bringing up interface eth0: Device eth0 does not seem to be preset, delaying initialization.      [FAILED]

To fix this, open /etc/udev/rules.d/70-persistent-net.rules. with your favorite text editor you will see something like this:

# This file was automatically generated by the /lib/udev/write_net_rules# program, run by the persistent-net-generator.rules rules file.## You can modify it, as long as you keep each rule on a single# line, and change only the value of the NAME= key. # PCI device 0x8086:0x100f (e1000) (custom name provided by external tool)SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:9c:00:16", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0" # PCI device 0x8086:0x100f (e1000) (custom name provided by external tool)SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:9c:00:18", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"



Take note of the MAC Address (HW Address) assigned by VMWare to the virtual interface and editudev's rules accordingly, for example, assume the virtual interface MAC Address is 00:50:56:9c:00:18, you will need it to edit rules so you end with something like this:

# This file was automatically generated by the /lib/udev/write_net_rules# program, run by the persistent-net-generator.rules rules file.## You can modify it, as long as you keep each rule on a single# line, and change only the value of the NAME= key.# PCI device 0x8086:0x100f (e1000) (custom name provided by external tool)SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:9c:00:18", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"# PCI device 0x8086:0x100f (e1000) (custom name provided by external tool)SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:9c:00:18", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

basically you have to delete unused network interface(s) rules and rename the one that has the current MAC Address.Finally, you need to validate MAC Address in /etc/sysconfig/network-scripts/ifcfg-eth0 to avoid , remember the MAC Address is the value of HWADDRESS.

jueves, 5 de enero de 2012

Re-Lock BitLocker Drive | Volver a bloquear un disco con BitLocker

I decided to put an end to the issue of not being able to lock my drives whenever I wanted to, so I started to search for answers and as usual CLI commands were the solution, using CLI drives can be locked again without a restart.

 

Syntax

manage-bde -lock <drive letter>: -ForceDismount

 

Something more like a “right click” thing is better and Jonathan at Jonamafun’s racetrack has a tutorial on this, just remember that an Administrator access is needed.

 

Sources/Fuentes:

http://jonamafun.blogspot.com/2009/11/how-to-re-lock-bitlocker-drive.html

http://technet.microsoft.com/en-us/library/dd894351(WS.10).aspx

 

 

Para volver a bloquear el acceso a un disco duro usando BitLocker sin tener que reiniciar la máquina, es necesario utilizar la consola:

 

Sintaxis

manage-bde -lock <letra del disco>: -ForceDismount

 

existe una forma más fácil de bloquear los discos y esto es utilizando el menú contextual, para lo que es necesario hacer algunas modificaciones en el registro de Windows, Jonathan tiene una entra da en su blog Jonamafun’s racetrack que cubre muy bien esta parte.

 

 

miércoles, 4 de enero de 2012

DTMF VoIP softphone tones | Tonos DTMF en softphones DTMF

When working with SIP IVRs it’s important to set the right configuration for DTMF tones.

 

 

Es importante utilizer la configuración correcta de acuerdo a lo que el IVR SIP utiliza para trabajar con tonos DTMF.

 

Sources/Fuentes:

http://www.cisco.com/en/US/docs/ios/12_3/sip/configuration/guide/chapter8.html http://www.voip-info.org/wiki/view/SIP+DTMF+Signalling

http://www.3cx.com/blog/voip-howto/dtmf-rfc2833/