Lat node names, service name and connections. Just for clarification.
An image that supports Lat terminals and Protocol translations such as the commserver or enterprise images, will automatically be aware of Lat service advertisements from other nodes.
hopper#show ver Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-J-L), Version 11.2(12.1), MAINTENANCE INTERIM SOFTWARE Copyright (c) 1986-1998 by cisco Systems, Inc. Compiled Mon 02-Mar-98 15:01 by tlane Image text-base: 0x0303F1BC, data-base: 0x00001000 hopper#show lat servi Service Name Rating Interface Node (Address) ALBIE 84 Ethernet0 ALBIE (aa00.0400.0a28) Ident: Welcome to OpenVMS VAX V7.1 ALFIE 67 Ethernet0 ALFIE (aa00.0400.1728) Ident: Welcome to OpenVMS (TM) VAX Operating System, Version V7.1 ALPHIE 71 Ethernet0 ALPHIE (0800.2be6.9ec9) Ident: @sys$manager:announce.txt
and because Lat is a valid input and output transport for the async ports, the router will respond to Lat solicits directed at the router.
hopper#show line 2
Tty Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns
2 TTY 9600/9600 - - - - - 0 0 0/0
Line 2, Location: "", Type: ""
Length: 24 lines, Width: 80 columns
Baud rate (TX/RX) is 9600/9600, no parity, 2 stopbits, 8 databits
Status: Ready
Capabilities: none
Modem state: Ready
Group codes: 0
Modem hardware state: noCTS noDSR DTR RTS
Special Chars: Escape Hold Stop Start Disconnect Activation
^^x none - - none
Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch
00:10:00 never none not set
Idle Session Disconnect Warning
never
Modem type is unknown.
Session limit is not set.
Time since activation: never
Editing is enabled.
History is enabled, history size is 10.
DNS resolution in show commands is enabled
Full user help is disabled
Allowed transports are lat pad v120 mop telnet rlogin nasi. Preferred is lat.
No output characters are padded ^
No special data dispatching characters --------------
line 2 3
transport input all
There are two ways to establish a Lat connection. A device can either request a connection to a service based on a Service advertisement that has been seen and cached ie;
hopper#show lat servi Service Name Rating Interface Node (Address) ALBIE 84 Ethernet0 ALBIE (aa00.0400.0a28) Ident: Welcome to OpenVMS VAX V7.1 ALFIE 65 Ethernet0 ALFIE (aa00.0400.1728) Ident: Welcome to OpenVMS (TM) VAX Operating System, Version V7.1 ALPHIE 71 Ethernet0 ALPHIE (0800.2be6.9ec9) Ident: @sys$manager:announce.txt
Or a device can solicit a connection to a node name "x", containing a port named "y" . in the following example, the vax has an application port (lta400) defined to connect to node hopper , port 2
ALFIE>mc latcp show port lta400 Local Port Name: _LTA400: Local Port Type: Application (Queued) Local Port State: Inactive Connected Link: Target Port Name: 2 Actual Port Name: Target Node Name: HOPPER Actual Node Name: Target Service Name: Actual Service Name:
and if I try to make the connection we see
>set h/dte lta400 %REM-I-TOQUIT, connection established Press Ctrl/\ to quit, Ctrl/@ for command mode
and
hopper#debug lat event
LAT event debugging is on
hopper#
hopper#
00:18:06: LAT: Host Initiated connection from ALFIE to :2, sc=1
00:18:06: LAT2: created new inbound session
00:18:06: LAT2: Host-initiated connection complete
00:18:06: LAT2: DataB: +FlowIn +FlowOut Parity 2A Mode Interactive(0) Speed *19200/*19200
00:18:06: LAT2: DataB ignored
hopper#who
Line User Host(s) Idle Location
* 0 con 0 idle 00:00:00
2 tty 2 idle 00:00:18 ALFIE
9 aux 0 Async interface 00:00:47
The router has taken the default node-name of "hopper" (Lat is case insensitive), which is the hostname of the router. If I wish to assign a different a node-name I can....
hopper#conf t Enter configuration commands, one per line. End with CNTL/Z. hopper(config)#lat node-name froggie hopper(config)#^Z
If the Vax now tries to connect ...
ALFIE>set h/dte lta400 %REM-I-TOQUIT, connection established Press Ctrl/\ to quit, Ctrl/@ for command mode %REM-E-PORTRXERR, port receive error -SYSTEM-F-HANGUP, data set hang-up %REM-S-END, control returned to node ALFIE %SYSTEM-F-HANGUP, data set hang-up ALFIE> hopper# hopper#show deb LAT: LAT event debugging is on hopper#
The router no longer responds to the solicit request from the Vax, because the router no longer has the node-name hopper.
To avoid the admin overhead of nodenames, we can define a service on the router ..
hopper#conf t Enter configuration commands, one per line. End with CNTL/Z. hopper(config)#lat service rodent enab hopper(config)#^Z
This now means that the router will send out Lat service advertisements for the service "rodent"
and sure enough the Vax can see the "SAP"s.
ALFIE>mc latcp show servi Service Name Status Identification ---------------- ----------- ------------------------------------------------- ALBIE Available .Welcome to OpenVMS VAX V7.1 ALFIE Available .Welcome to OpenVMS VAX V7.1 ALPHIE Available @sys$manager:announce.txt PRINTERC Available RODENT Available ALFIE>set h/lat rodent %LAT-S-CONNECTED, session to RODENT on node FROGGIE established %LAT-I-TODISCON, type ^\ to disconnect the session User Access Verification Username: hopper# hopper# 00:26:10: LAT: Host delay = 4 tics 00:26:10: LAT: Got new inbound host connection 00:26:10: LAT10: created new inbound session hopper#
Note that the method of connection to a service name and a node/port pair is different. The Service connection gives a vty session
hopper#who
Line User Host(s) Idle Location
* 0 con 0 idle 00:00:00
9 aux 0 Async interface 00:00:36
10 vty 0 idle 00:01:05 ALFIE
The node/port combination gives a tty connection.
hopper#who
Line User Host(s) Idle Location
* 0 con 0 idle 00:00:00
2 tty 2 idle 00:01:24 ALFIE
9 aux 0 Async interface 00:00:22
This is worth bearing in mind depending on whether you want a host based application or terminal session during the connection. Applications and print queues tend to prefer the tty style connection.
I'm curious as to why this is, but I'm too lazy to find out right now.