Common Problems

This section discusses various symptoms of common problems and their associated solutions.

• Source route bridge software is not bridging one or more protocols.
  • Verify that all frame types for the LAN interfaces that are attached to the source route bridge are loaded and bound individually. For example, when bridging over a given token ring LAN interface, make sure that both the TOKEN-RING and the TOKEN-RING_SNAP frame types for that interface are loaded and bound to the source route bridge.
  • When a protocol is routed on a LAN interface or WAN port, bridging of that protocol is blocked automatically on that interface or port. Bridging cannot occur unless routing of that protocol is disabled.
  • Load FILTCFG and select Configure Source Route Bridge Filters to view the filter table. Verify that no filter exists for the protocol that you want to bridge.

• End stations cannot make a connection.
  • If you have loaded upgraded server software that has been modified to support buffer sizes larger than 4202, verify that the LAN drivers you are using support this size (some have been found to set the largest frame size allowed to 4202).
  • Check for duplicate ring numbers or for bridges on the same ring that have different ring numbers assigned to the interfaces. Load BRGCON and select Source Route Port Statistics. If duplicate ring numbers exist, the appropriate error counter increments.
  • Make sure that all Novell end stations on the source route bridge topology have loaded ROUTE.COM (for clients) and ROUTE.NLM (for servers).
  • If you loaded ROUTE.NLM or ROUTE.COM and modified some of its parameters, use version 1.12 (dated May 1, 1991) or later. We recommend that you use ROUTE.NLM and ROUTE.COM 4.11 (dated February 4, 1994) or later.
  • Check how often the hop count limit is being reached. Load BRGCON and select Source Route Port Statistics.
  • In a relatively large source route topology, it might be advisable to design the spanning tree root bridge in the center of the topology so that the spanning tree (single-route) explorer frames are less likely to reach a hop count limit.
  • You cannot log in to a server that is more than the maximum number of hops that you configured for the source route bridge software.

    For example, in Figure 11 , Server A is seven hops away from the client, but Server B is more than seven hops away from the client. IPX RIP lets the client from Ring 1 log in to Server A and see Server B through the SLIST command. However, because the bridges are configured to discard packets more than seven hops away, the client cannot log in to Server B.

  Figure 11
  Hop Count Limitation
  

• A protocol seems to be routed and bridged.
  • Router and bridge configuration was not done through NIASCFG. Because NIASCFG informs the bridge about which protocols are routed, the bridge does not receive this information if NIASCFG is bypassed. Therefore, the bridge does not block routed traffic.
  • When the bridge was bound to a WAN interface, the Plan to Route IPX option was set to No when, in fact, routing is configured.

• SRBRIDGE clients do not work.
  • Load MONITOR and display the LAN/WAN Information for the SRBRIDGE LANs. The information under the Custom Statistics option might indicate the source of the problem. The solution might be as simple as assigning a Virtual Ring Number value in NIASCFG or loading the correct ROUTE.NLM version (1.12 or later).
  • If the following messages appear frequently, this indicates that one or more of the clients cannot use the SRBRIDGE driver: Send Packet Too Many FragmentsSend Packet Raw Transmit Attempts

    NOTE:  All Novell router clients have been validated to operate with the SRBRIDGE driver (IPX, TCP/IP, and AppleTalk).

  • If the following message appears frequently, then the hop count of a peer connection is greater than seven:Receive Packet Route Too Long

    Use ROUTE.NLM and ROUTE.COM 4.11 or later to correct the problem.

  • Verify that the frame type is correct for the protocol. For example, IP and AppleTalk require TOKEN-RING_SNAP, whereas IPX, NetBIOS, and SNA require TOKEN-RING.

• Connection to an X.25 network cannot be established.

  Verify that the local DTE address matches the remote DTE address at the other end of the WAN link.

• Incorrect spanning tree parameters are configured.
  • When implementing standby (parallel) bridges, the value of the IPX RETRY COUNT parameter, specified in the NET.CFG file on the client, should be changed from the default (20) to 40 or greater. This change allows the workstation to recover successfully from a bridge failure.
  • On NetWare servers, use the default value for the source route update interval (when configured through NIASCFG), or equivalently, the default TIME parameter for ROUTE.NLM (when configured through the AUTOEXEC.NCF file). The default is 3 seconds.

• Incorrect frame types are configured.
  • IP and AppleTalk require TOKEN-RING_SNAP.
  • IPX, Spanning Tree Protocol, NetBIOS, and SNA require TOKEN-RING.
  • If you are using the virtual internal ring with SRBRIDG.LAN, IP and AppleTalk require TOKEN-RING_SNAP, whereas IPX, NetBIOS, and SNA require TOKEN-RING.