user's topology: clinet pc---switch---router---swtich---server
When the client accesses the server, http service is normal, but SQL server service is abnormal.
On the router deny 1433 ACL is configured. So SQL service cannot be used. Delete ACL and the service recovers.
Anable ACL on the router and the matching relation of ACL and windows is as follows:
137=NETBIOS Name Service
138=NETBIOS Datagram Service
139=NETBIOS Session Service
593=Unassigned IPC Server
1068＝Installation Bootstrap Proto. Cli.
2784＝world wide web-development
If one service is abnormal and other service is normal, configrm the problem according to matching relation of ACL and windows.