我的學習手記 A technical geek blog: DNS

Showing posts with label DNS. Show all posts

Saturday, October 12, 2024

Fortigate DNS and Server DNS different case connection rejected on firewall

When the destination URL on CDN e.g. AWS.

If your Fortigate DNS and Server DNS different case connection denied on firewall

Solution:

To align with those device DNS is same.

Thursday, September 14, 2017

How to setup VMware Security Server to support login outside firewall and within DMZ at the same time?

Possible Solution: Using DNS name with different IP address resolve from external and internal

e.g. vdi001.abc.com

It will resolve from Internet / external network a IP address A (e.g. 203.x.x.x – You Public or external IP address on firewall which is use for NAT mapping)

Then, it resolves IP address B (e.g. 192.168.x.x – Your VMware Security IP address (DMZ))

But, it only work for using RDP and Blast protocol.

Remark:

1. RDP and Blast support using DNS name

2. PCoIP did not support DNS name (It must be IP address)

Saturday, November 5, 2016

Change fixed DNS setting via PSExec to deploy and run the PowerShell

Change fixed DNS setting via PSExec and PowerShell

1. Copy the "change_dns.ps1" to the target machine "C:\source\PSTools\change_dns\"

The "change_dns.ps1" content:

$dnsservers = "8.8.8.8"
$computers = Get-Content env:computername
foreach ($comp in $computers)
{

$adapters = gwmi -q "select * from win32_networkadapterconfiguration where ipenabled='true'" -ComputerName $comp
foreach ($adapter in $adapters)
{
$adapter.setDNSServerSearchOrder($dnsservers)
}

}

2. PsExec command to run the PowerShell remotely:
(Copy the "change_dns.ps1" into the same folder of PSExec)

C:\source\PSTools\change_dns>PSExec \\Computer1 -u "admin" -p PASSWORD PowerShell -NoProfile -ExecutionPolicy Bypass C:\source\PSTools\change_dns\change_dns.ps1

If success, will return the following value:

PsExec v2.2 - Execute processes remotely
Copyright (C) 2001-2016 Mark Russinovich
Sysinternals - www.sysinternals.com

__GENUS          : 2
__CLASS          : __PARAMETERS
__SUPERCLASS     :
__DYNASTY        : __PARAMETERS
__RELPATH        :
__PROPERTY_COUNT : 1
__DERIVATION     : {}
__SERVER         :
__NAMESPACE      :
__PATH           :
ReturnValue      : 0

PowerShell exited on Computer1 with error code 0.

Reference:
http://stackoverflow.com/questions/1786185/run-powershell-scripts-on-remote-pc
http://blog.danskingdom.com/allow-others-to-run-your-powershell-scripts-from-a-batch-file-they-will-love-you-for-it/
https://community.spiceworks.com/topic/385832-need-to-change-dns-servers-remotely-on-workstations-no-dhcp-server

Sunday, March 6, 2011

Public DNS

Google Public DNS

8.8.8.8

8.8.4.4

http://code.google.com/intl/zh-HK/speed/public-dns/

Norton DNS

Change your DNS settings to: 198.153.192.1 and 198.153.194.1

http://nortondns.com/

http://status.nortondns.com/

OpenDNS

208.67.222.222

208.67.220.220

http://www.opendns.com/

Comodo Secure DNS

156.154.70.22

156.154.71.22

http://www.comodo.com/secure-dns/switch/

http://www.comodo.com/secure-dns/support/faq.html

Test of DNS settings and availability of domain name

http://www.dns-info.cz/en/dns-test/

http://www.dnswatch.info/articles/dns-update

Tuesday, December 8, 2009

Beware of Unused NICs (From: http://windowsitpro.com/article/articleid/96610/beware-of-unused-nics.html)

Executive Summary:
When you're configuring a new Microsoft Windows server that has multiple network interface cards (NICs), it's important that you disable any NICs that aren't plugged in to the network. If you don't disable an unused NIC, problems can arise on domain controllers (DCs) running Domain Name System (DNS). The DNS server problems can impede the performance of client computers.

For more information:

http://windowsitpro.com/article/articleid/96610/beware-of-unused-nics.html