TRBSHT.TXT


Examining Your IPX Network 
===============================

How to use the IPX network management console (IPXCON) to examine any NLSP
system or NetWare LAN in your IPX network.  IPXCON can help you identify
problems with your routers and LANs.

IPXCON uses SNMP to exchange management information and statistics with
NLSP routers on the network.  IPXCON operates over either IPX or Internet
Protocol (IP) networks using the User Datagram Protocol (UDP) transport.

Selecting a Server or Router 
----------------------------
IPXCON gives you management access to any server or dedicated router that
uses NLSP as its routing protocol.  In this section, the term "Local
System" refers to the server or router from which you load IPXCON; "Remote
System" refers to any other server or router on the network.

> If You Want to Access the Local System 

To gain management access to the local system, just type the following
command at the prompt:

LOAD IPXCON <Enter> 

IPXCON accesses the local system by default.

> If You Want to Access a Remote System

Complete the following steps to gain management access to a remote server
or router: 


PROCEDURE 

1. Go to a local server or router and type the following command at the
prompt: LOAD IPXCON <Enter> 

The "Available Options" window appears. 

2. SNMP Access Configuration is already highlighted; press 
<Enter>.

The "SNMP Access Configuration" window appears. 

3. Select the "Transport Protocol" field.

The "Transport Protocol" window appears. 

4. Select TCP/IP or IPX. 

The "SNMP Access Configuration" window reappears. 

5. The Host Address field is already highlighted; press <Ins> to see a list
of available hostnames and addresses.

NOTE: If you already know the system's hostname or address, just type it
in. 

6. Scroll through the list to find the system; press <Enter> to select it. 

IMPORTANT: IPXCON can only access systems that are running IPXRTRNM.  If
you do not see the system in this list, check whether IPXRTRNM is loaded on
that system. 

7. Press <Esc> to return to the "Available Options" menu.

In a few moments, IPXCON begins recording statistics for the system you
selected.

Determining Where NLSP is Running in Your Network 
--------------------------------------------------
After migrating your network, you can identify which LANs on your IPX
network are using NLSP or RIP - or both - as the routing protocol.

If you partitioned your IPX network into routing areas, note the following
points: 

- The procedure in this section shows only the LANs and NLSP routers that
are within the same routing area as the system you are currently
monitoring. 

- RIP should be running only on the routers at area boundaries.

For an explanation of routing areas, see the "IPX Upgrade for NetWare
Servers 1.1 NLSP Migration Guide".

To find LANs on which NLSP or RIP is running, complete the following steps:


PROCEDURE

1. Load IPXCON and select a system as described in "Selecting a Server or
Router", above. 

2. Select NLSP Information.

The "NLSP Information" window appears. 

3. Select LANs.

The Known LANs window displays the following information about each NetWare
LAN of which the local system is aware: 

Network Number 
External network number of the LAN.
Throughput 
Number of Megabits Per Second (MbPS) reported by the LAN board. 

Delay 
Time, in microseconds, for packets to reach the LAN from the Designated
Router.

If NLSP is importing RIP routes to a LAN, the entry is labeled RIP Active. 
If the entry is labeled Unreachable, the LAN is no longer accessible from
the local system.  No label means that NLSP is the only routing protocol
running on the LAN and that the LAN is reachable. 

4. Select one of the LANs to see which NLSP routers are on it. 

Checking Your Network for Inactive Routers 
------------------------------------------
You can use IPXCON to identify routers on your network that are inactive
that is, not routing for some reason.  This information can often help you
locate a defective network interface. 

To check your network for inactive routers, complete the following steps: 

PROCEDURE

1. Load IPXCON and select a system as described in "Selecting a Server or
Router", above. 

2. Select NLSP Information.  
The "NLSP Information" window appears. 

3. Select Routers.  
IPXCON lists the NLSP routers known to the system you are monitoring. 

4. Scroll through the list.

Any router labeled Unreachable is either down or has a defective network
interface.

Any router labeled Overloaded has run out of memory and can no longer
process NLSP routing information.

Routers not labeled Unreachable or Overloaded are operating properly. 

5. Select one of the routers.

A new window displays the following information: 

- Attachment 
NLSP routers or IPX networks connected to the router you selected. 

- Network 
If the attachment is an IPX network, the networks external network number;
if the attachment is a router, the router s internal network number. 

- Media Type 
LAN or WAN medium, such as Ethernet 802.3 or X.25.

- Throughput 
Number of Mbps reported by the routers interface board.

NOTE: For WANs, the throughput value is an estimate. Because of rounding
errors, this estimate is typically less than the actual speed of the WAN
link. 

- Delay 
Estimated time, in microseconds, for packets to be forwarded to the
attached medium.

Checking Your Network for Duplicate Network Numbers 
---------------------------------------------------
Each external network number that identifies a LAN on your IPX network must
be unique.  Incorrect configurations and other problems can cause two LANs
to have the same external network number.

One way in which this can occur is when a bridge connecting two LAN
segments fails, a condition known as a "split LAN".  When the bridge fails,
each segment becomes a separate LAN but retains the same external network
number.  As a result, routers forwarding packets to that network number see
two destinations and simply choose the nearest one.

To check your network for duplicate network numbers, complete the following
steps: 

PROCEDURE

1. Load IPXCON and select a system as described in "Selecting a Server or
Router", above. 

2. Select "NLSP Information".
The "NLSP Information" window appears. 

3. Select LANs.  The "Known LANs" window appears.  The LANs are listed in
numeric order by network number.

4. Scroll through the list of LANs; look for duplicate network numbers. 

Checking Your Network for Duplicate System IDs 
-----------------------------------------------
To check your network for duplicate System IDs, complete the following
steps: 

PROCEDURE

1. Load IPXCON and select a system as described in Selecting a Server or
Router, above. 

2. Select NLSP Information.  The "NLSP Information" window appears. 

3. System Information is already highlighted; just press <Enter>. 

4. The field associated with Detailed NLSP System Information is already
highlighted; just press <Enter>. 

5. Check the numbers associated with the Sequence Number Skips and Own LSP
Purges fields. 

If either of these numbers is increasing, there are two or more NLSP
routers on your network with the same System ID.  Change the System ID on
one of the routers.


Finding NLSP Routers with Insufficient Memory 
---------------------------------------------
To check your network for routers that have run out of memory, complete the
following steps: 

PROCEDURE

1. Load IPXCON and select a system as described in "Selecting a Server or
Router", above. 

2. Select NLSP Information.

The "NLSP Information" window appears. 

3. System Information is already highlighted; just press <Enter>.

The field associated with Level 1 Overloaded should read No.  If it reads
Yes, the router does not have enough memory to process routing information.

4. As a further check, select "Detailed NLSP System Information".

The "Level 1 Database Overloads" field indicates how many times the router
has run out of memory.

Finding the Designated Router on a LAN 
--------------------------------------
The Designated Router is an NLSP router elected by its peers to represent
and keep track of the connectivity of its LAN.  The Designated Router
handles exchanges of link state information on behalf of all other NLSP
routers on the LAN. 

To find the Designated Router on a LAN, complete the following steps: 

PROCEDURE

1. Load IPXCON and select a system as described in "Selecting a Server or
Router", above. 

2. Select Circuits.

The Circuits window displays the name, type, and state of each circuit. 
Only broadcast (LAN) circuits have Designated Routers. 

3. Select a broadcast circuit.

The Circuit Information window displays, among other information, the name
of the Designated Router and the external network number of the LAN it
represents.

4. To see more information about the Designated Router, complete the
following steps: 

- 4a. Record the name of the Designated Router. 

- 4b. Press <Esc> until you return to the "Available Options" menu. 

- 4c. Select SNMP Access Configuration. 

- 4d. Select IPX as the transport protocol. 

- 4e. Type the name of the Designated Router in the Host Address field,
then press <Enter>. 

- 4f. Press <Esc> to return to the "Available Options" menu.  

In a few moments, IPXCON will begin recording statistics for the Designated
Router.




