First briefly introduce the company's network structure:
The switch closet, the router connects to Shanghai's peer router through the DDN line. The following client is connected to the switch.
Server situation profile:
The server system is Win2000 Server, dial-up access via ISDN. Agent software is Wingate.
Fault description:
The ISDN device is normal, the connection is normal, but cannot be online.
Troubleshooting:
The first thing I thought is that the ping is the command, test what is connected.
I entered: ping www.163.com
Return information: Pinging 163.com [202.106.185.77] with 32 bytes of data: reply from 172.16.64.1:destination unreachablereply from 172.16.64.1:destination unreachablereply from 172.16.64.1:destination unreachablereply from 172.16.64.1:destination unreachable
According to the return prompt, it feels a bit wrong. Why do I ping is 163.com, returning to 172.16.64.1. This address is an IP of the Shanghai Router. But the first sentence found 163.com's IP is 202.106.185.77. This indication DNS is no problem! The problem may be on the route.
Change your ideas: Try unplug the network cable of the net card. See if the ISDN connection is normal if the route is not passed. Test results: Everything is normal. Using IPConfig, you can clearly see the IP address that is automatically assigned locally.
The problem is determined: This has explained that the data can be normally not passed. But after plugging the network cable, the fault is still. After contact with the Shanghai Information Department, the other router has closed the 80-port, in order to prevent employees from accessing the Internet. So I use the agent's method to try to access the Internet, set the ISDN connection proxy server in the IE property, still can't. I feel that the packet is still unable to route. It is estimated that the opponent Deny has dropped most of the agent ports.
I thought about it, suddenly I thought that Win2000 also took NAT function, so I viewed the routing table. Enter: Route print command Displays all of its default routes through 172.16.64.1 in the routing table. That is, the address of 0.0.0.0 is forwarded to 172.16.64.1. I think, if you don't forward it to the router, don't you solve it? So try to delete the default route, use the route delete 0.0.0.0 command to complete. Disconnect the ISDN connection again, restart the ISDN connection. Ping 163.com, success. (Note that this time is no tuning network) fault successfully excluded.
Written by Willpower, 2003.7.14
