Sybase Installation Failed

Almost at the end of the installation, installation fails with error and aborts the installation of the Sybase. The situation repeats and ends always in the same way.What can cause this error?

The installation of Sybase is indeed tricky. Before I succeeded with it, I have failed 1000 times. The successful one installation was the 1001st trial :)

Sybase listener is not starting with the new settings in interfaces file

One of the final step in Sybase installation can be change in the port that the server binds to, or adding a specific network interface, where sybase should listen on. This can be done using the sp_listener procedure and change in the interfaces file. Here,  there is an example of interfaces file and the failed command sp_listener. We want to allow Sybase to listen on the external interface 192.168.10.20:

SAP01
        master tcp ether SAP01 5000
        master tcp ether 192.168.10.20 5000
        query tcp ether SAP01 5000

SAP01_BS
        master tcp ether SAP01 5001
        query tcp ether SAP01 5001

SAP01_XP
        master tcp ether SAP01 5002
        query tcp ether SAP01 5002

SAP01_JSAGENT
        master tcp ether SAP01 4900
        query tcp ether SAP01 4900

and the port change from within of Sybase:

[root@SAP01 ~]# su - sap

-bash-4.3$ isql -Usa -SSAP01 -Ppassword

3>
4> sp_listener 'status'
5> go
 proto  host  port  status
 -----------------------------------------------------
 tcp   SAP01  5000  active

DBCC execution completed. If DBCC printed error messages, contact a user with
System Administrator (SA) role.
(return status = 0)

1> sp_listener 'start','192.168.10.20:5000'
2> go
Msg 15936, Level 16, State 1:
Server 'SAP01', Procedure 'sp_listener', Line 107:
An error was encountered when starting a listener with protocol tcp, host
192.168.10.20, port 5000.
Msg 15038, Level 16, State 1:
Server 'SAP01', Procedure 'sp_listener', Line 107:
The specified port 5000 is invalid.
DBCC execution completed. If DBCC printed error messages, contact a user with
System Administrator (SA) role.
(return status = 1)"

Well, one line in the configuration looks sometimes differently.  In my case in the interfaces file there was no entry for: