Environment
Novell Client for Windows 2000/XP/2003
Situation
Error: "NetWare Services: Cannot find network name"
Error: "The tree or server cannot be found"
Error: "MAP-X-890: The specified server is unknown."
Error: "LOGIN-X-890: The specified server is unknown."
On a workstation where specifying that a particular server
name (e.g. "MYSERVER") in the Novell Client login dialog's"Server:" field was able to successfully logon, it was found that
setting up a persistent Windows drive mapping to a volume on"MYSERVER" would fail. (Unless the workstation had already
connected to or logged on to "MYSERVER".) Specifying the IP
address of "MYSERVER" instead of the server name would also
succeed, which suggested a name resolution-related problem.
A LAN trace of the failing scenario showed that the failure
was occurring when the following multiple factors came together at
the same time:
- The Novell Client was being requested to perform a "wildcard" name resolution, meaning it could not be assumed whether the name represented the name of an eDirectory tree or the name of an NCP Server. In this situation the Novell Client must attempt resolution of both, which effectively cuts in half the amount of time available for each name type.
- SLP was the only name resolution method available that knew how to map "MYSERVER" into one or more network addresses. In other words, although the DNS, HOSTS and NDS name resolution methods were being used, none of them were able to provide an answer to the query for "MYSERVER".
- The workstation was configured to use SLP by multicast, instead of being setup to perform SLP name resolution through one or more SLP Directory Agents (DAs). The use of SLP over multicast can cause relatively long multicast timeouts to be involved in the SLP name resolution attempts.
- In the responses SLP provided in this environment, it was shown that "MYSERVER" was reporting itself as registered on three different IPv4 NCP addresses. (e.g. 192.168.10.1, 172.20.107.152, and 192.168.30.1.) But only one of these three addresses were reachable from the workstation. In the course of resolving the "MYSERVER" name into an address to connect to for NCP, the workstation was having to time out on one or more of the unresponsive IPv4 addresses.
All together, these factors would cause the time needed for
successful name resolution to exceed the 10-second default "Name
Resolution Timeout" configuration in the "Advanced Settings" of the
Novell Client Properties.
Other situations, such as when browsing under "NetWare
Servers" for "MYSERVER", or specifying "MYSERVER" in the "Server:"
field on the Novell Client login dialog, would appear to work. (But
because the name was already known to the an NCP Server name,
this was eliminating the first factor in the
above list.)
Resolution
The failure could be eliminated in any of the following ways,
in order of preference:
- Establish an SLP Directory Agent (DA) for all the services to register with, and configure the SLP clients to use this DA when performing SLP name resolution. This allows for the SLP clients to have a much faster unicast conversation directly with the DA, instead of using SLP over multicast to then wait and time out for responses.
- Increase the "Name Resolution Timeout" setting to a value higher than the default 10 seconds, such as 15 seconds, or higher if necessary. If the name resolution methods being used in an environment are going to take more than the usual amount of time (e.g. SLP must use multicast plus additional delay factors; or DNS has been configured with a long list of DNS domain suffixes to attempt with) then increasing the "Name Resolution Timeout" can be a suitable solution.
Increase the value only as needed, since increasing the Name Resolution Timeout can cause other operations longer to time out. For example, applications that send the Novell Client names that appropriately cannot be resolved by Novell name resolution methods. - Define the name (e.g. "MYSERVER") such that it is available over another name resolution method besides SLP. If the environment is unable to establish an SLP DA, defining the name to be available in DNS or even the HOSTS file would provide the configured Novell Client name resolution methods a faster way to map the name into an IPv4 network address.
- If possible, make sure the NCP Server the workstation will need to connect to will not report being bound to addresses which cannot be reached by the client workstation. This can improve name resolution and connection speed by not forcing the Novell Client to attempt reaching addresses that are unresponsive from the workstation's position on the network.
The default "Name Resolution Timeout" value of 10
seconds established by the Novell Client is expected to be a fair
balance between speed and necessity that enough time be allowed for
successful completion under normal circumstances across all the
available name resolution methods.
Some environments will find that not even 10 seconds is
required for successful name resolution, and will choose to reduce
the "Name Resolution Timeout" to a smaller value that improves
performance when the Novell Client needs to fail quickly for a name
that simply does not belong to Novell services.
Other environments may need or choose to increase the "Name
Resolution Timeout" to something longer, due to additional factors
in the network name resolution environment that require additional
time to allow successful completion over the available name
resolution methods.