You are mentioning ping, however you are using NetNEUI protocol.
Did you try tcp/ip ? i.e.

C:\Firebird1\bin>isql HML:e:\interbase\data\db_access_control_01.gdb -u sysdba -p masterkey

Ivan
http://www.volny.cz/iprenosil/interbase



==============
I have Firebird in 3 servers: Development (DVL), Homologation (HML)
and
Production (PRD)
I have other clients machines.

IBConsole work fine on all of machines.
IBExpert too.
I can ping all the servers from all clients.
Connections with Interserver is working too.

But... when I use ISQL...

>From machine Client-1 the connection with

DVL fails.
HML and PRD work fine.

>From machine Client-2 the connection with

DVL and PRD fails.
HML work fine.

Look at the commands below... I have tried change the name of the
machines
by your IP Adress bu the error persists.

(work)
==============================================================
C:\Firebird1\bin>isql
\\HML\e:\interbase\data\db_access_control_01.gdb -u
sysdba -p masterkey
Database: \\HML\e:\interbase\data\db_access_control_01.gdb, User:
sysdba
SQL>
==============================================================

(doesn�t work)
==============================================================
C:\Firebird1\bin>isql
\\DSV\e:\interbase\data\db_access_control_01.gdb -u
sysdba -p masterkey
Statement failed, SQLCODE = -902

Unable to complete network request to host "DSV".
-Failed to establish a connection.
-Logon failure: unknown user name or bad password.

Use CONNECT or CREATE DATABASE to specify a database
==============================================================

Anybody have any idea ?