Advantage Knowledgebase Item
Tuesday, August 13, 2002
Advantage Clients ( General )
6420 Unable to "discover" the Advantage Database Server
A 6420 error indicates that the Advantage client's process for finding the Advantage Database Server has failed. To communicate with 32-bit applications via IP, the Advantage Database Server creates two sockets and listens for specific multicast and mail (NetBIOS mailslot) packets. For IPX networks, the Advantage Database Server uses SAPs for discovery. Generally, a 6420 error is caused by a network device blocking these discovery packets or by a server not responding to the packet requests.
The following are possible solutions:
1. Advantage Database Server versions 6.11 and newer provide the ability to connect by specifying an IP address in the ADS.INI file. This direct connection method eliminates the discovery process and will resolves 6420 errors.
For a direct connection, configure the IP_PORT on the server in the ADS.CFG for Netware or in the Advantage Configuration Utility for Windows 2000/NT. Then, specify the IP address and port in the ADS.INI file.
For further instructions, see LAN_IP/LAN_PORT in the Advantage help file. This functionality is not available for IPX connections.
2. Verify that the client can ping the server by IP address and by name (example: PING <machine name>.) If this fails, install WINS, DNS or modify the workstation's LMHosts file.
3. A firewall may be eliminating Advantage UDP/IP packets. The firewall router logs will indicate the Advantage packets that are being filtered. See the Advantage help file for configuring the IP port for the Advantage Database Server, and then configure the firewall to allow UDP and IP packets through the configured port.
4. If the first connection fails with a 6420, but subsequent connections succeed, the client may not be receiving a response from the DNS, WINS, or LMHosts file for name resolution. An ARP (Address Request Protocol) request is sent out to get the address of the mailslot server. This ARP will go out on IPX or IP since it uses NetBios. If it goes out on IPX then the request gets handled. However, if IPX is not installed then IP is used. If a gateway does not have IP installed, ARPs sent to the gateway will not get a response. After several tries, a broadcast is sent and a response is received. Then the server is found and a connection is established. This can take up to 12 seconds under this scenario. For a limited time this address is kept for quick reference.
The problem is that the name of the Windows NT server machine is not being resolved to an IP address. Make sure either a DNS, WINS or LMHosts name resolution is in place.
5. A 6420 may be caused by a WSOCK32.DLL that is corrupt, that is non-Microsoft, or that is outdated (1994 or older). Update the WSOCK32.DLL by placing in the Windows\System directory or by placing it in the application directory.
6. 6420 (Unable to discover the Advantage Database Server) errors can occur after updating to v5.7 or newer client communications DLL. Earlier versions of the Advantage client communications layer DLL used an obsolete Microsoft API call that sometimes worked when the standard method of discovery of the Advantage Database Server failed. ADSCOM.TXT generated from a version 5.6 or older environment utility would show a call to OldGetRemoteAddress.
7. A client using a dial-up connection to a network and ADSDOSIP can get 1015 or 6420 errors on either Windows 95 or Windows NT if they started ADSDOSIP before initializing the dial-up connection. Initialize the dial-up connection before starting ADSDOSIP.
8. 6420 Error: "Unable to Find the Advantage Service or Unable to find a Bindery on the Network" When Connecting to Novell from a PC that has IP and IPX. There may also be 7030 errors logged in the ADS_ERR.DBF file. This can be caused by the following registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Extended Systems\Advantage Communications
If this key exists with a Word value of IP ONLY = 1, then the client workstation will only try to use IP to communicate with the server. This is a problem if the Advantage Database Server is running on a Novell NetWare server where only IPX is intended for use, and the Advantage Internet Server is not being used. Remove the registry key to fix the error.
9. 6420 or 6060 Error occurs with 32-bit applications but SCANBIND or 16-bit applications find the Advantage Database Server for NetWare. The 32-bit Advantage client requires a file server on the local network that has a bindery or bindery emulation and will respond to a FindNearestServer request when the Advantage Database Server is on a NetWare server that does not have the IP protocol installed. This can be caused by the NetWare Console Setting: "Reply To Get Nearest Server: OFF". On a NetWare file server on the local network, enter: SET Reply To Get Nearest Server = ON
10. A 6060 or 6420 error may occur when restructuring a table with Advantage Data Architect(ARC) v6.11 if the restructure is ran from a client workstation that does not have the Advantage Database Server running on it. This is due to a bug where the temporary table used during the restructure was being managed on the local hard drive, but the server type was incorrectly set to match the current connection type when accessing local data. Data Dictionary bound tables should not see this problem. Upgrade to ARC 18.104.22.168 or newer to solve the problem. or a workaround would be to use local server to open the table to be restructured, or use ALTER TABLE or AdsRestructureTable( ).
11. With the initial release of Advantage Database Server (ADS) v5.7, there existed the possibility of some client connection problems. Symptoms would include 6060 or 6420 errors, applications known to work before upgrading would now receive these errors. To fix, ADS v5.702 is available for download at www.advantagedatabase.com/downloads. This update will address the 6060 errors with CA-Clipper applications running against a Windows 2000 server. For 32-bit applications, both the server and client software must be updated. Updated installation files are available at the address mentioned above.
12. 6420 errors can be caused if you try to connect to a Windows NT server using pre-4.21 CA-Clipper libraries, or if you try to use the non-Windows NT version of the 4.21 clipper libraries. Upgrade the client version.
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