You can use the decnet_migrate tool to get the following information for each node in your network:
You can also use the decnet_migrate show path function to trace network routes between one node and another.
Use this tool when you need a detailed map of parts or all of the complete network topology. If you have routers that use the Simple Network Management Protocol (SNMP), the decnet_migrate tool cannot collect information about them. Use the tools those routers provide to collect network topology information.
Collecting this information with the decnet_migrate tool can take a significant amount of time depending on the options you select.
The DECnet-Plus network management documentation explains how to use the decnet_migrate commands collect, report, and show path in detail. Sections 2.8.1 and 2.8.2 describe which NCL and NCP commands to use to trace network paths in the DECnet-Plus environment.
Table 2-3 shows the differences between Phase IV and DECnet-Plus node names.
Characteristics | Example |
---|---|
Phase IV node names are:
|
MYNODE |
DECnet-Plus node names are:
|
ABC:.eng.node1 |
Use the following commands to find a system's node synonym or to find a DECnet-Plus full node name from a system's node synonym:
To Find A: | Use This decnet_register Command: |
---|---|
Phase IV synonym | decnet_register>show node node-id |
Full node name | decnet_register>show node node-id |
Do the following to find your system's current operating system and version:
If the Prompt Is: | Then the Operating System Is: |
---|---|
Username: | OpenVMS |
login: | Digital UNIX |
If the Operating System Is: | Enter: |
---|---|
OpenVMS | $ show system |
Digital UNIX | # strings /vmunix|grep '(Rev') |
To find basic routing circuit information, use Network Control Program (NCP) commands for Phase IV nodes and Network Control Language (NCL) commands for DECnet-Plus nodes. Refer to your NCP documentation for information about NCP commands.
The following information can be useful when you need to solve routing circuit problems:
Do the following to find a circuit name, type, and state:
To Find Routing Circuit: | Enter This NCL Command: |
---|---|
Name | ncl>show node node-id routing circuit * name |
Type | ncl>show node node-id routing circuit * type |
State | ncl>show node node-id routing circuit * state |
Routing circuit adjacencies result from nodes exchanging identification information. Finding circuit adjacencies is a quick way to:
Routing circuit adjacencies exist for wide area network (WAN) circuits, and local area network (LAN) circuits. Use the following NCL command to find routing circuit adjacencies:
ncl>show node node-id routing circuit
circuit-id -
_ncl>adjacency * all status
When you look at broadcast circuit adjacencies, the output can be extensive because many adjacencies can exist at one time. It can be more useful to request certain types of information rather than all information.
For example, you could use the following NCL command:
ncl>show node node-id1 routing circuit circuit-1
adjacency -
_ncl>node-id2 type
Tracing a path from one end system to another can isolate network reachability problems and also can provide network topology information. The information in this section describes the type of information you need before you trace a network path.
Use the Network Control Program (NCP) to get network path information from Phase IV nodes. Use the Network Control Language (NCL) to get network path information from DECnet-Plus nodes. Table 2-4 lists the information you need to trace a network path and how to identify this information.
Information | Description | ||||||||
---|---|---|---|---|---|---|---|---|---|
Node Addresses |
Nodes have addresses that DECnet uses when sending data through a
network. Phase IV nodes only have one node address; DECnet-Plus nodes
can have up to six NSAP addresses; three that NSP use and three that
OSI Transport use.
Phase IV node addresses and NSAP addresses are different. However, you can translate a Phase IV node address into an NSAP address.
|
||||||||
Network entity titles (NETs) | Used to identify a node when it is not necessary to identify the transport software in use. A NET has the same format as an NSAP with a selector byte of %x00. | ||||||||
System type | A system can be an end system, a level 1 router, or a level 2 router. |
A Phase IV node has one address; a DECnet-Plus node can have multiple NSAP addresses. You can determine a node's address as follows:
For This Node Type: | Enter: |
---|---|
Phase IV |
The NCP command:
tell node-spec show exec |
DECnet-Plus |
The NCL command:
show node node-id routing port * nsap address |
If you cannot get the remote node's address in this manner, you need to log in to that system directly.
A network entity title (NET) has the same format as a system's network service access point (NSAP), except the last two digits are set to 00. For example, if the NSAP is 49::00-0D:AA-00-04-00-7F-34:20, the NET is 49::00-0D:AA-00-04--00-7F-34:00.
If you know a system's Phase IV address, you can do the following to convert it to an NSAP (see your DECnet introduction documentation for details about NSAPs):
Step | Action |
---|---|
1 | Ensure that the NSAP local area is in the Phase IV area in hexadecimal notation. For example, the Phase IV area 1 becomes the NSAP local area 00-01, and the Phase IV area 63 becomes the NSAP local area 00-3F. |
2 |
Convert the Phase IV node ID to the NSAP node ID:
|
Example of Phase IV Address Conversion
In this example, the network IDP (initial domain part) is 41:45436192:, the DSP (domain-specific part) is local-area:node-id:20, the Phase IV address is 43.258, and the node uses the NSP transport. You create the NSAP as follows:
IDP and selector -> 41:45436192:local-area:node-id:20 43 decimal -> 2B hexadecimal (local area) (43 * 1024) + 258) -> 44290 decimal 44290 decimal -> AD02 hexadecimal AD02 swapped -> 02AD hexadecimal (node ID) Resulting NSAP -> 41:45436192:00-2b:aa-00-04-00-02-ad:20
If you know a system's NSAP, you can do the following to convert it to a Phase IV address:
Step | Action |
---|---|
1 | Check that the local area is less than or equal to 63 decimal or 3F hexadecimal and the node ID field begins with aa-00-04-00. If both of these conditions do not exist, then the NSAP does not contain a Phase IV address and cannot be converted. If it does, go to the next step. |
2 | Extract the last four digits of the node ID field. |
3 | Swap the last two pairs of digits, and convert the value to decimal. |
4 |
Calculate the Phase IV area and ID values:
If the calculated area value is not equal to the area value obtained from the NSAP's local area field, the NSAP does not contain a valid Phase IV address. |
In this example, the NSAP is 37:81076541234:00-19:aa-00-04-00-62-64:21. You calculate the Phase IV address as follows:
19 hexadecimal (from local area) -> 25 decimal 62-64 (from node-id) -> 6462 hexadecimal 6462 hexadecimal -> 25698 decimal 25698/1024 -> area of 25 25698 - (25 * 1024) -> node ID of 98 Resulting Phase IV address -> 25.98
You can trace a network path for a pure DECnet-Plus environment and for a mixed environment that has DECnet-Plus and Phase IV nodes.
You can trace the path from one node to another with the following command:
$ run decnet_migrate DECNET_MIGRATE>sho path from NAMES:.NETA.NODEA to NAMES:.NETB.NODEB
Do the steps in the following table to trace a network path from one DECnet-Plus end system to another:
Step | Action |
---|---|
1 | Find the destination NSAPs. |
2 | Analyze the NSAPs to find the area addresses of the destination system. |
3 |
Find a DECnet-Plus router that the source node uses. Do the following:
A DECnet-Plus router may not exist. See the procedure in Section 2.8.2 if the next node in the path is a Phase IV router. If the next node in the path is not a Digital router, see that system's documentation. |
4 |
If the router you find in the previous step is in the same area as your
destination node, go to the next step. If the router is in a different
area than the destination node, do the following:
|
5 |
When you find a router located in the same area as the destination
node, do the following:
|
Your network can contain DECnet-Plus and Phase IV nodes. If you start to trace a path from a DECnet-Plus node and the next router in the path is a Phase IV router, do the following:
Step | Action |
---|---|
1 | Exit NCL and invoke NCP (or invoke NCP at the NCL prompt). |
2 | Use NCP to get the Phase IV node address of your destination node and the router. |
3 |
Find the next node in the path. Use the following NCP commands (the
router-id can be the node name or the Phase IV address):
ncp>tell
phase_iv-node-id show node -
|
4 | If the next node in the path is not the destination node, repeat the commands in step 3, using the next node that the show node command displays as the next-node-id, until you reach the destination node. |
5 |
If NCP returns an error message, the next node in the path could be a
DECnet-Plus node. Do the following:
|
If you are tracing a network path from an X.25 DA circuit, you cannot use NSAP or NET information to find the next node in the path. Use the following procedure to help you trace a path from an X.25 DA circuit:
Step | Action |
---|---|
1 | Find the reachable address subentity that has a prefix that best matches your required destination NSAP. |
2 | Select a DTE from the DTE Addresses attribute and determine the node address (NSAP or Phase IV synonym) associated with the remote DTE address. |
3 | If you cannot determine the node address, try to log in to the remote node using X.29 (PAD) and continue tracing the network path from the remote node. |
When NCL displays a node address in response to a SET or SHOW command, it uses the services of DECdns to translate the address into a node name and displays the name along with the address.
If there is a problem with accessing a remote name server that prevents the translation from completing, NCL may take a long time translating addresses to names. If this happens, enter a Ctrl/Y to terminate NCL, then make the following definition prior to executing NCL:
$ DEFINE NCL$ENVIRONMENT NOBACKTRANS
This causes NCL to bypass the address-to-name translation. To use this option on a systemwide basis, add this logical definition (with the /SYSTEM qualifier) to SYS$MANAGER:NET$LOGICALS.COM.
This chapter describes the network reachability tests you can use in the DECnet-Plus environment.
The topics in this chapter are:
Test | Description |
---|---|
Quick reachability |
Provides a fast indication that a remote node is reachable using
applications such as
dlogin or
set host with the node address instead of the node name. If
you cannot connect to a node using its node name but can connect to it
using the address, the cause could be a naming service problem.
For Digital UNIX systems, you can also use OSI Echo function (OSI ping). |
Loopback | Loopback tests (node level, circuit level, and LAN with LLC test messages) let you thoroughly use network software and hardware by sending data through various network components and returning that data to its source for comparison. |
DECnet Test Sender and Receiver ( dts/dtr) |
Throughput tests that allow you to load test the ability of different
systems to exchange data. The
dts/dtr tests are also useful if you want to check Transport
layer connections.
Parameters are available to regulate such variables as message length, test duration, and type of data used. |
X.25 and OSI Transport IVP (OpenVMS systems only) | These tests check if the X.25 or OSI transport software is working correctly. Your installation documentation describes them. |
You can use the loopback tests described in this section for DECnet-Plus systems. Refer to your DECnet Phase IV documentation if you need details about similar tests for Phase IV systems.
Test Type | Description |
---|---|
Node level |
Checks the logical link capabilities of a node by exchanging test data
between DECnet tasks in two different nodes or in the same node. You
use NCL to run this test, which enables you to connect to a loopback
mirror application. The types of node-level tests are:
|
Circuit level | Checks a DECnet circuit by looping test data between a mop task and the communication hardware on one or two systems. |
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