The ultimate solution to the problem of ICBC's Web site not open

First of all you should try:
NET silver is best to use IE
Menu: Tools--> Internet Options--> Security tab, Trusted sites, delete all ICBC-related sites (or delete them all),
99% of the mistakes were made by this damned place.

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The following are reproduced:
Try it on the top.

Recently a lot of users can not open ICBC website and personal net Silver landing page, on this, I spent a little time research, found that may be your system's MTU (maximum transmission unit) value set to 1500, resulting in access to some sites, ICBC website is one of them, Can change the MTU value of 1450 can be resolved, I tested, set to 1492, you can open ICBC website, but not open personal net Silver landing page, can only be set to the value of the following 1492, I tested with 1450 can all normal open ICBC website page.

Specifically, how to change the MTU value, or to change the registry, a lot of data on the Internet to change the MTU value, but only for the WIN98 system, the following is applicable to XP system MTU value change steps:

manually set the network adapter's MTU value

With the Regedit,hkey_local_machine\system\currentcontrolset\services\tcpip\parameters\interfaces\ primary key open, there are several folders below, Each card that represents the installation of the machine, browse each folder in turn, and look at the key value of the IPAddress (or dhcpipaddress) on the right side of the window, if the value is the IP of the network card you are using to connect to the Internet, you need to modify this folder.

Enter this folder, find a primary key named MTU, if not, create this DWORD value, the name MTU modifier key value is 1450 decimal, restart it.

If you are not or are afraid of changing the registry, you can also use the Windows Optimizer Master or Super Bunny changes. For example, to open the optimization master, point Network system optimization inside the maximum transmission unit size, change to 1450, click Optimization, you may turn on the optimization master again to see the MTU value, its value displayed as other values, not just changed 1450, do not care about it, it is optimized master read from the "Internet Mode selection" The status value set by the feature has actually been changed to 1450, you can open the registry and view the key values described above for verification.

Add:

If you change the network card MTU value of 1450 can not solve the problem, appear sometimes open, and sometimes not open the image, may be the network environment is too bad caused, or continue to try to change the MTU value, you can gradually reduce the MTU, until the connection is the most stable. If you change the MTU value can not be resolved, it is recommended to check the system is currently open software, such as: antivirus software, network firewall, system optimization settings software, such as Third-party software, a shutdown test to see exactly what is caused by the software, to make the corresponding changes.

So how do you determine if an MTU value is the best fit?

"Start"-"Run" enter "CMD" return, enter the DOS environment, enter the following command line:

Ping-f-l 1472 192.168.1.1< Carriage return >

Tip: "192.168.1.1" is the IP address of the gateway, 1472 is the length of the packet, and the parameter "-l" is a lowercase l.

If you can ping, indicating that the packet does not need unpacking, can be sent through the network Guan Fa. If present: Packet needs to be fragmented but dfset. As shown in the following illustration, the packet needs to be split and sent. At this point, reduce the packet length, and then execute the ping command above. Try a few more times from 1400 to 1472 to find the right packet length. The value of the MTU is obtained by adding the packet length to 28 bytes of packet header (ICMP). If the MTU value for the gateway is detected to be 1500, no modification is required. If the gateway has a firewall ping, try to set the MTU to 1400 directly.

I am here for the MTU value of 1422+28=1450, Guangdong Telecom ADSL, as shown in the following figure.

MTU value-Small material:

The Maximum transmission unit (Maximum TRANSMISSIONUNIT,MTU) is the maximum datagram size (in bytes) that can be passed on a layer of a communication protocol. Maximum Transmission Unit This parameter is usually related to the communication Interface (network interface card, serial port, etc.).

Internet protocol allows IP fragmentation, so that the datagram can be divided into small enough fragments to pass the link with the largest transmission unit smaller than the original size of the datagram. This fragmentation occurs at the IP layer (the third layer of the OSI model, the network layer), which uses the value of the maximum transmission unit that sends the packet to the network interface on the link. The fragments of the original grouping are tagged so that the IP layer of the destination host can be grouped together to form the original datagram.

In Internet protocol, the "Path Maximum transmission unit" of an Internet transmission path is defined as the minimum value of the maximum transmission unit of all IP hops on the path from the source address to the destination. Or, from a different point of view, is the maximum number of transmission units that can pass through the "path" without further fragmentation.

RFC1191 describes the "Path Maximum Transmission unit discovery method", which is a technique for determining the maximum path transmission unit between two IP hosts, and is designed to avoid IP fragmentation. In this technique, the source address will datagram the DF (Don ' tfragment, do not fragment) position bit, and then gradually increase the size of the datagram sent--any device on the path that needs to fragment the packet will discard the datagram and return a "datagram too large" ICMP response to the source address- In this way, the source host is "learning" the largest maximum transmission unit that can pass through this path without slicing.

Unfortunately, more and more networks are blocking ICMP transmissions (say, for example, to guard against Dos attacks)-This makes the path's maximum transmission unit find that the method does not work, and its common performance is that a connection works with low data traffic, but once a large amount of data is sent simultaneously, Immediately hangs up (for example, when using IRC, the customer will find no response after sending a ping that prohibits IP spoofing because the connection is blocked by a large number of welcome messages). And, in a network that uses Internet protocols, the "path" from the source address to the destination is often modified dynamically in response to a variety of events (load balancing, congestion, power outages, and so on)-which may cause the path's maximum transmission unit to change during transmission-sometimes even repeatedly. As a result, more packets are lost while the host is looking for a new maximum transmission unit that can work safely.

For most Ethernet LANs nowadays, the maximum transmission unit value is 1500 bytes. But systems like PPPoE reduce this number, which makes it possible to find a method using the largest transmission unit: Some sites that are behind a poorly configured firewall become unreachable. It is possible to find a workaround for this situation, but it depends on which part of the network you are controlling. These methods include changing the MSS (maximumsegment size, maximum segment size) of the first grouping that is used to establish a TCP connection at one end of the firewall.

For some IBM systems that support older versions of the Ethernet protocol (such as xseries), it may be possible to operate on the current common LAN only after the maximum transmission unit is set to 1492.