Some school builds one NE40-4 device. Configure one NAT board as internal address to access public network. After debugging test users' network segment and they can access it. After a period some users cannot access network and need to change IP address and then can be online.
Some users need to change address and then can access network. Before it is thought that their addresses are used by others. Disconnect network cable of users and laptop configures their address. Test and they cannot access network. Change address and it indicates that NATconversion is not problematic.
Execute display nat session at the device and check whether these users' addresses have conversion entry or not. If the address has conversion entry and corresponding address to converse port, ping the user's address and it can be pinged. Check conversed public network address of earlier private network and public network address of changed private network address. They are different. The network that users cannot access is broadcast address. It is related with broadcast address. Change source address of broadcast address and the problem is solved. Trace the address of private newtwork and it is conversed,
1. Some user's address is used by others.
2. NAT address conversion configuration is problematic.
3. Address of NAT address pool is useless.
Configure NAT conversion, address of address pool cannot contain broadcast address and network address with address pool mask. Address pool cannot ahve network segment address and broadcast address.