Can't download Gmail attachments

LỖI KHÔNG THỂ TẢI FILES ĐÍNH KÈM TỪ GMAIL 
Sáng nay tình cờ gặp cái lỗi không thể tải files đính kèm từ Gmail được, kể cả khi dùng các trình duyệt khác nhau như Firefox, Chrome, IE8..v.v..


Trên tất cả trình duyệt đều xuất hiện cái lỗi đại loại như:


Cannot download this file. An error occured while security connnection to mail-attachment.googleusercontent.com

The connection has timed out
The server at mail-attachment.googleusercontent.com is taking too long to respond.
 hoặc là nó sẽ tự động tải lại trang web Gmail.

Sau một hồi mò mẫm thì cũng tìm ra nguyên nhân là do tụi ISP chặn link :
"mail-attachment.googleusercontent.com"

( Công ty Tôi đang dùng mạng của CMC, VNPT, FPT.)

Cách giải quyết cũng rất đơn giản. Các bạn chỉ cần đổi DNS là có thể tải files từ Gmail về bình thường.
Lưu ý là DNS google ( 8.8.8.8, 8.8.4.4 ) và OpenDNS ( 207.67.222.222, 208.67.220.220 ) cũng bị chặn nhé.


Các  bạn sử dụng các DNS sau:
 4.2.2.1
4.2.2.2

Hoặc:
4.2.2.3
4.2.2.4

Good luck! (^_^)

CCNA LAB - 4.9 DHCP (Dynamic Host Configuration Protocol)


LAB 4-9: Dynamic Host Configuration Protocol (DHCP)

You are the network administrator at Ranet, and have to configure the router Ranet-GW to connect
between LAN and Internet, and to do as DHCP server for LAN as below:
(via Console)
1. Enable and set IP address on LAN interface to be the first IP of the subnet 10.0.0.128/28
2. Enable and set IP address on serial interface to be the last IP of the subnet 77.8.210.0/30
3. Set the default route to let the connection out to the internet.
4. Configure to let this router translate between the addresses in this LAN and the addresses
ISP gave us (19.5.39.129 – 19.5.39.130)

Remark: use ACL no.1 and pool named“Ranet” only!

5. Configure to let this router do as DHCP server for the hosts in LAN. You have to supply all
information that is necessary for hosts to connect to the internet, and do not forget to
exclude addresses of the gateway and the switch.

Remark: use pool named “Ranet” also!

If everything is correct, all hosts have to be able to open website http://www.ranet.co.th

Solution:

CCNA LAB - 4.8 Virtual Private Network (VPN) - IPsec (Site-to-Site)



LAB 4-8: Virtual Private Network (VPN) – IPsec (Site-to-Site)

You are the Network Administrator at Ranet Branch Office, and have to newly configure the Ranet-Br router to let your own host connect to the internet and connect to the hosts in Headquarter (192.168.0.0/24) via Site-to-Site IPsec VPN as below:
(configure via console terminal for Ranet-BR router)

1. Enable LAN interface on Ranet-BR and set IP address to be the first assignable IP of 192.168.1.0/28 network.

2. Enable WAN interface on Ranet-BR and set IP address to be the last assignable IP of 202.170.100.28/30 network.

3. Set IP address on Host-BR to be the last assignable IP of 192.169.1.0/28 network, and set IP of Gateway and DNS server (202.170.100.54) also.

4. Config the route and NAT on Ranet-BR to let the Hosts in LAN connect to the internet (do not forget to exclude the VPN traffic).
(for NAT, use access-list no.100 and pool name “Ranet” that contain the global IP received from ISP as 202.170.100.9 – 202.170.100.14)

5. Config the Site-to-Site IPsec VPN by using the properties as below:

- For IKE phase I:- Policy Priority 101; Encryption Alg. AES-128 bit; Hash Alg. Secure HAsh standard; Authen method. Pre-Shared Key; Diffie-Hellman group #5 and lifetime at 86,400 sec. Use “ranetvpnpass” as key. Please note that IP address of WAN interface of Ranet-HQ is 202.170.100.130.
- For IKE phase II: Use Transform-set name “Ranet” and ESP transform using AES with HMAC-SHA as authentication Alg.
- Use crypto map name “Site-to-Site” with sequence no.101 and access-list no.101 to be the VPN traffic.

If everything is correct, Host-BR should be able to open website www.ranet.co.th, and test ping with Server-HQ 192.168.0.7 in Headquarter network.

Solution:

Kích hoạt tính năng Nested 64bit & Hyper-V VMs trong vSphere 5

How to Enable Support for Nested 64bit & Hyper-V VMs in vSphere 5



With the release of vSphere 5, one of the most sought out feature from VMware is the ability to run nested 64bit and Hyper-V guest virtual machines in a virtual ESXi instance. Previous to this, only 32bit virtual machines were supported as the VT-x/AMD-V Hardware Virtualization CPU instructions could not be virtualized and presented to the virtual ESX(i) guest. This feature is quite useful for home and lab setups in testing new features or studying for VMware certifications and running multiple vESX(i) instances.

You will still be required to have a 64bit capable system and CPU and you will need to be running ESXi 5.0, this will not work for ESX(i) 4.x or older.



The above diagram depicts the various levels of inception where pESXi is your physical ESXi 5.0 hosts. We then create a vESXi 5.0 host which will contain the necessary Hardware Virtualization CPU instructions to support a 64bit nested guest OS which I've created as another ESXi host called vvESXi.

Note: You will not be able to run a 4th level nested 64bit VM (I have tried by further passing the HV instructions in the nested guest) and it will just boot up and spin your CPUs for hours.

This feature by default is disabled in ESXi 5.0, to enable this virtualized HV (Hardware Virtualization) you will need to add the following string vhv.allow = "TRUE" to /etc/vmware/config of your Physical ESXi 5.0 host


Once the configuration change has been made, the feature goes into effect right away. A reboot of the system is not necessary. To verify, you should now be able to power on a 64bit guest OS and see that the HV instructions bits are being passed into the guestOS which will then allow you to run a nested 64bit guestOS. You can also verify by looking in the vmware.log file of the virtual machine and grep for the string "monitorControl.vhv" and if you see the following message, then Virtualized HV is not enabled.


In the past to run a virtual ESX(i) instance, a few advanced .vmx configuration entries were needed as documented here. With ESXi 5.0, if you are using virtual hardware version 8, then you do not need to make any additional changes. If you are using hardware version 4 or 7, then you will need to add a few changes to the VM's configuration file.
Creating vESXi 5.0 Instance using Hardware Version 8:
1. To create a virtual ESXi 5.0 instance, start off by just creating a standard RHEL5/6 64bit VM using the vSphere Client
2. Once the VM has been created, edit the settings of the VM and change over to the "Options" and now have the ability to select a new guestOS type: VMware ESXi 5.x or VMware ESXi 4.x under the "Other" section.




Note: I'm not sure why these two additional guestOS type is not available from the default creation menu, but are available after the initial VM shell is created.

3. You are now ready to install ESXi 5.0 in this new vESXi host and then you can create and power on nested 64bit guestOS within that vESXi instance as denoted from the picture below

 
Creating vESXi 5.0 Instance using Hardware Version 4/7:
1. To create a virtual ESXi 5.0 instance, start off by just creating a standard RHEL5/6 64bit VM using the vSphere Client

2. Now you will need to add the following advanced .vmx parameter: monitor.virtual_exec = "hardware" which can be done through the vSphere Client and/or editing the .vmx parameter manually.

3. Next you will need to add some cpuid bits, depending if you are running an Intel or AMD CPU, the respective entries are required:

Intel Hosts:
cpuid.1.ecx = "----:----:----:----:----:----:--h-:----"
AMD Hosts:
cpuid.80000001.ecx.amd = "----:----:----:----:----:----:----:-h--"
cpuid.8000000a.eax.amd = "hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh"
cpuid.8000000a.ebx.amd = "hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh"
cpuid.8000000a.edx.amd = "hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh"
4. You are now ready to install ESXi 5.0 in this new vESXi host and then you can create and power on nested 64bit guestOS within that vESXi instance

By using a VM that is hardware version 8, you can easily automate the creation of vESXi 5.0 instance by changing the guestOS string in the .vmx parameter to "vmkernel" and the above configurations other than "vhv" string needed for either an Intel or AMD system are automatically configured.

Creating a vHyper-V Instance on physical ESXi 5.0:

1. To create a virtual Hyper-V instance, start off by creating a Windows 2008 Server R2 64bit VM using the vSphere Client

2. If you are using Hardware Version 7, you will need to follow the instructions in "Creating vESXi 5.0 Instance using Hardware Version 4/7" to add the additional parameters to the VM. If you are using Hardware Version 8, you just need to change the guestOS type to VMware ESXi 5.0

3. You need to add one additional .vmx parameter which tells the underlying guestOS (Hyper-V) that it is not running as a virtual guest which in fact it really is. The parameter is hypervisor.cpuid.v0 = FALSE

4. You are now ready to install Hyper-V in a virtual machine and you can also spin up nested 64bit guestOSes in this virtual Hyper-V instance.
 














As you can see, now you can even run Hyper-Crap, err I mean Hyper-V as a virtualized guest under ESXi 5.0. I did not get a chance to try out Xen, but I'm sure with the ability to virtualize the Hardware Virtualization instructions, you should be able to run other types of hypervisors for testing purposes.

This is a really awesome feature but note that this is not officially supported by VMware, use at your own risk.


Nguồn http://www.virtuallyghetto.com

YẾU TỐ QUYẾT ĐỊNH THÀNH CÔNG

Để thành công thì chúng ta cần yếu tố gì?
 



Trong cuộc sống nếu:

A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z

tương đương với giá trị:

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26 thì:

- Làm việc tích cực chỉ là:
H+A+R+D+W+O+R+K = 8+1+18+4+23+15+18+11 = 98%.

- Kiến thức vẫn chỉ là:
K+N+O+W+L+E+D+G+E = 11+14+15+23+12+5+4+7+5 = 96%

- Hay là may mắn?
L+U+C+K = 12+21+3+11 = 47%.

- Hoặc tình yêu cũng chỉ là :

L+O+V+E = 12+15+22+2 = 54%

Vấn không phải! Vậy là cái gì nhỉ?
- Tiền bạc chăng ? – Không, không phải, vì:

M+O+N+E+Y = 13+15+14+25= 72%

- Leadership? – Cũng không vì :
L+E+A+D+E+R+S+H+I+P = 12+5+1+4+5+18+19+9+16 = 89%

Để vươn đến đỉnh cao và để đạt đựơc sự tuyệt đối (100%) trong cuộc sống, điềuthật sư giúp chúng ta vươn cao hơn, xa hơn chính là thái độ. Chỉ có thái độ là 100%:


A+T+T+I+T+U+D+E = 1+20+20+9+20+21+4+5 = 100%


CCNA LAB - 4.7 NAT


LAB 4-7: Network Address Translation (NAT)
You are the network administrator at Ranet, and have to config the Ranet-GW router via Console Terminal to let hosts in our LAN that have IP address: 192.168.0.193 - 192.168.0.206 can connect to the internet.
Your ISP has given global IP for 6 IP as 25.5.5.65 - 25.5.5.70.

Remark: 

1. Use ACL no.1 for Local IP list.
2. Use pool name “Ranet” for Global IP list. 


Solution:

CCNA LAB - 4.6 Access List


LAB 4-6: Access Control List (ACL)
You are the network administrator at Ranet, and have to config router Ranet-HQ to connect its LAN
to Branch network and Internet, and to config Access-List to control traffic as below:
(via its console)
1. Enable and set IP address on LAN interface to be the first assignable IP of this subnet.

2. Enable and set IP address on each serial interface to be the last assignable IP of its own subnet.

3. Set RIPv2 to be the router protocol on this router to exchange route with Ranet-BR

4. Set default route to allow the connection with internet.

5. Set access-list to prevent the connection from hosts in LAN as:
- allow only Admin-Host to telnet to Ranet-CoreSW (password: ranetpass)
- Not permit only User-Host1 to connect to any site in the internet.
- Any traffic beside these should be allow.

Remark: Use ACL no.100 only!, and use as short as possible to gain %Completion

Solution:

CCNA LAB - 4.5 Port Security


LAB 4-5: Port Security

You are the network administrator at Ranet,and would like to enable Port-Security on the access ports of Ranet-SW to prevent the use of another switch connected that let multiple hosts connect through the same port at the same time, and to prevent the unauthorized host connect via some port.
So all you have to do are: (Config via Console)

1. Enable Port-Security on all access ports (except Gig1/1, Gig1/2), and set parameter to allow only 1 MAC Address per port and the action when violation happened is shutdown port.

2. On port Fa0/1, now there is the authorized host connected (Host1), set the allow MAC Address on this port by “SecureSticky” method.

3. On port Fa0/3, now there is the unauthorized host connected (Rogue3),set the allow MAC Address to be 0030.F295.15C6.

If everything is correct, you will see ports Fa0/2 and Fa0/3 change status to down (err-disabled) when there is the attempt to connect from unauthorized hosts, and Host1 will not be able to connect with the unauthorized hosts (192.168.0.58 – 192.168.0.60) .

---------------------- End -----------------------------


Solution:

Những yêu cầu và những điều kiện tiên quyết cho hệ thống cài Exchange 2010


CÀI ĐẶT EXCHANGE 2010

Phần cứng cần thiết


Bộ xử lý : Cấu trúc x64 với Intel hay nền tảng AMD64
Bộ nhớ :

Phụ thuộc vào role cài đặt
  • Tối thiểu cho mỗi server : 4GB
  • Tối thiểu khi kết hợp với roles : 8GB
Thường thì them từ 2-10MB cho mỗi mailbox . Bộ nhớ lớn nhất cho roles mailbox là 64GB

Dung lượng ổ cứng : Đây là thành phần quan trọng nhất cho role mailbox .
Bạn cần 1.2GB dung lượng ổ cứng để dành cho cài đặt Exchange
  • Thêm 500MB cho mỗi gói ngôn ngữ UM
  • Thêm 500MB cho hang đợi về cơ sở dữ liệu cho Edge hoặc máy chủ Hub Transport Server
Về hệ điều hành , bạn có thể dung Windows Server 2008 hoặc Server 2008 R2
Có thể dung Hyper-V từ Microsoft để cài hệ điều hành lên.

Những yêu cầu về bộ vi xử lý 













Những yêu cầu về bộ nhớ















Đối với hệ điều hành thì tất nhiên phải là 64bit rồi . Có thê sử dụng phiên bản hệ điều hành sau


Windows Server 2008 Standard Edition (SP2 )
Windows Server 2008 Enterprise Edition (SP2 )
Windows Server 2008 Standard R2
Windows Server 2008 Enterprise R2

Đối với công cụ quản trị của Exchange , thì quản trị qua những hệ điều hành sau

Windows 7
Windows Vista with Service Park 2
Windows Server 2008 SP2
Windows Server 2008 R2


Tất nhiên , S viết tới đây thì có nhiều người thắc mắc là nên dung phiên bản nào là phù hợp với doanh nghiệp và túi tiền của họ ? Vậy sau đây sẽ là câu trả lời cho bạn:



Exchange Server 2010 sử dụng cho cả 2 phiên bản Standard và Enterprise
Phiên bản được xác định bằng product key . Khi bạn nhập key product license là phiên bản sẽ hiểu . Trong chế độ Trial mode , nó là Enterprise
  • Với bản Standard , giới hạn ở 5 cơ sở dữ liệu trên mỗi server mà thôi
  • Với bản Enterprise thì có thể lên tới 100 cơ sở dữ liệu trên mỗi server
Client Access Licensing (CAL) thì hỗ trợ ở 2 phiên bản.


Vậy là bạn đã biết doanh nghiệp mình nên dung bản nào rồi đúng không ?



Sau đây là những điều kiện tiên quyết cho việc cài đặt lên Server 2008 R2

Cài đặt Microsoft .NET Framework 3.5 SP1

Cài đặt .NET Framework 3.5 Family Update

Cài đặt Windows Remote Management 2.0

Cài đặt PowerShell v2

Trên các server HT và MB cài đặt Microsoft Filter Pack

Cài đặt theo Typical : từ dấu nhắc lệnh , vào thư mục Script của Exchange, bạn gõ

  • Sc config NetTCPPortSharing start=auto
  • ServerManagerCmd-ip Exchange-Typical.xml – Restart
Cài đặt role UM thì gõ
  • ServerManagerCmd –I Desktop- Experience
Trên Hub Transport và Mailbox Server cài đặt Microsoft Filter Pack

Từ cửa sổ PowerShell , gõ Import-Module ServerManager
Sử dụng Add-WindowsFeature cmdlet gõ

Add-WindowsFeature NET-Framework,RSAT-ADDS,Web-Server,Web-Basic-Auth,Web-Windows-Auth,Web-Metabase,Web-Net-Ext,Web-Lgcy-Mgmt-Console,WAS-Process-Model,RSAT-Web-Server,Web-ISAPI-Ext,Web-Digest-Auth,Web-Dyn-Compression,NET-HTTP-Activation,RPC-Over-HTTP-Proxy,Desktop-Experience –Restart

Kết luận sau khi khởi động bằng cấu hình dịch vụ TCP port tự động sử dụng (chỉ roles CAS)

Set-Service NetTcpPortSharing -StartupType Automatic


Khuyến cáo nữa là trước khi cài đặt Exchange 2010 , bạn nên update hệ điều hành


Update AD Schema and Preparing Domain



Để update Schema , từ dòng lệnh trong command line gõ :
  • Setup /PrepareLegacyExchangePermissions ( or Setup /pl)
  • Setup / PrepareSchema (or setup /ps)
  • Setup /PrepareAD (or setup /p)
Để prepare domain , từ dòng lệnh gõ :
  • Setup /PrepareDomain (or setup /pd)
  • Setup /PrepareDomain:<Domain FQDN > (or setup /pd:<FQDN >)
  • Setup /PrepareAllDomains (or setup /pad)

Hy vọng bài viết trên giúp bạn thực hiện việc cài đặt Exchange Server một cách dễ dàng .


(Bài viết của S ( Mr.Bin ) trên itlab.com.vn )

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