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Chapter 9

Troubleshooting Novell Connectivity

Although this serial connection may be a T1, many sites still use 56Kbps

DDS circuits or low CIR (committed information rate) frame-relay connec-
tions.

As a NetWare network grows, the volume of RIP and SAP traffic also

grows. Eventually, a 56Kbps connection (or Frame Relay connection) will be
overwhelmed with RIP and SAP updates, to the point where user data can no
longer be transferred. A saturated T1 may also have difficulty providing ade-
quate bandwidth to support large RIP and SAP updates.

In addition, the connection to a file server from the client requires a

response to the GNS broadcast described previously. Although the router
responds in the absence of a server, the subsequent connections may fail due
to timeouts or other issues. In addition, the server or client may be over-
loaded. A protocol analyzer is a good way to review this issue, although
debug

commands can be used with caution. If the issue involved is an over-

loaded server, a solution may involve use of the ipx gns-round-robin con-
figuration command. If more than one NetWare server is listed in the SAP
table as being an equal distance away, this command provides a limited form
of load balancing.

Conversely, there may be times when the router responds to the client too

quickly. Although this is a rare occurrence in modern networks, the default
delay of 0ms can be changed with the ipx gns-response-delay configu-
ration command.

There is also a scenario referred to as the backdoor bridge. In this exam-

ple, a bridge connects two IPX networks and leaks routing information. The
show ipx traffic

command should be used to determine whether the bad

hop counter is incrementing. If it is, a protocol analyzer should be used to
find a source address that matches the remote node and not the router.

SAP Congestion Management in IPX RIP

Service advertisements can generate a significant amount of traffic in
medium-scale networks. In large networks, they can cause high processor
utilization and overall degradation of the network.

Without using NetWare's NLSP to control IPX RIP and SAP datagrams,

an administrator may use access lists to block SAP traffic from crossing an
interface. This solution does have shortcomings, however. Any resource that
is restricted by an access list is unavailable to the opposing portion of the
network.

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