nwServerList Problem

Question:

I use
nwServerList(4)
to return a list of all Netware servers in my environment.
However, the list returned is not complete. The help for nwServerList says that request #4 will return a list of all known server names. How do servers become "known"? We have recently upgraded some servers to Netware 6.5 and some of them are missing from the list. Is nwServerList version-specific?

I am going to try using nwserverList(8) to get a list of all trees, and then looping through the list using nwserverlist(4,tree); would you expect that to be more successful?

Answer:

The 1st question I need to get answered is whether or not this upgrade to NetWare v6.5 included removing the IPX protocol from the upgraded servers. Is your NetWare environment being migrated from IPX to pure IP?

The reason that I ask about IPX -> IP conversion is that the 2 protocols behave very differently when it comes to enumerating the resources available on a network. IPX uses SAP [Service Advertising Protocol] to broadcast out announcements about the available servers & trees on the network. As long as the SAP packets aren't being blocked or otherwise filtered, your workstation receives them and the Novell Client builds up a list of known servers & trees. NCP over IP [a.k.a. "Pure IP"] use SLP [Service Location Protocol] to locate resources on the network. SAP and SLP behave very differently. SLP broadcasts to announce services only happen on the local IP subnet and don't cross router boundaries. SLP can also use multicasts to announce services, but if your routers aren't configured properly, the SLP multicasts get blocked. So, simply trying to enumerate the available trees & servers in a Pure IP configuration doesn't work like it did in an IPX environment. Once the Novell Client knows the IP address of a SLP DA [Directory Agent], it can specifically to have a server name resolved to a network address [e.g. similar to how DNS works], but simply saying "give me a list of all the tree & server names" isn't something that happens.

Once you are connected to a tree and are authenticated to that tree, you may search the tree server objects and obtain a list of available servers that way. Then, the NCP protocol takes care of resolving the server object name to a network address by way of the network address information stored in the server object in the directory tree.

So, in summary, if you have a eDir tree hosted by servers in multiple IP subnets, it is possible that nwServerList() may not be able to "see" the servers on remote subnets for purposes of enumerating them. Likewise, if you have multiple trees, and all of the servers that belong to a tree are on remote subnets, then your workstation won't automatically list the tree as being available. However, if you know the DNS name or IP address of a server, you can use that in place of a regular server name for purposes of establishing a NCP over IP connection to the server. Once that is done, the Novell Client then has access to that remote server's bindery and then the Novell Client may become aware of more servers & trees.

Another note to make is that the Novell Client also attempts to obtain lists of available servers and trees based on the contents of the bindery [including the bindery emulation on NDS/eDdir capable servers] of the server that is your primary server connection. If you have multiple server connections and you designate one of them as the primary connection, that may change the # of available servers & trees that nwServerList() reports depending on what other servers & trees the primary server is in communication with.

Article ID:   W17083

File Created: 2007:07:03:14:28:12

Last Updated: 2007:07:03:14:28:12

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