Conference decwet::windows-nt

5850.0. "help required with Windows NT subnet mask..." by QCAV02::PMK () Wed Mar 26 1997 21:15

Hello,

We are facing problem with Windows NTAS 4.0 subnet.  The problem details are
enclosed below.  
    
I would like know whether this configuration is valid or not.  
If it is not valid what is subnet mask to be used, so that Alpha will 
communicate to router.
    
Thanks inadvance and regards
P. Malakondaiah
Product Support Group
Digital Equipment (India) Limited
===============================================================================
Customer 	: 	IIM Calcutta (Joka)
System		:	Alpha 200 4/233
Operating System:	Windows-NTAS V4.0 

Problem Details	:	We are unable to ping to ROUTER at the same site and
			same network ( Address details provided below ) from
			the Win-NTAS (Alpha).

Protocols used	:	NetBEUI, TCP/IP, IPX/SPX.

Observation	:	The Win-NTAS Server can see the Neighbourhood wrkstns.
			If TCP/IP addressing scheme is changed, it can ping &
			telnet to UNIX system ( which is in a different NET )
			[ Diagram enclosed below ].

Local Simulation:	We had simulated the problem in our office and our
			observation is as follows :
			System used :  Alpha 200 4/100  with Win-NTAS V4.0
				       ( Actual site also has Serv.Pack-2 )
				       PriorisLX 575 with Win-NT V3.51
				       Inhouse Network.
			IP Address of Alpha :  206.103.11.47  255.255.255.240
			IP Address of P/LX  :  206.103.11.33  255.255.255.240

			The above systems cannot ping to each other. However,
			they can see each other in their neighbourhood(NetBEUI) 
			
			If the Sub-net mask is changed to 255.255.255.0 then 
			the systems can ping each other. The sub-net mask and
			IP addresses has been allocated to IIM by Service
                        provider.

Router Ethernet Port :  206.103.11.33   255.255.255.240
Router WAN Port      :  202.54.9.185    255.255.255.252
DNS Server (VSNL)    :  202.54.9.1

Alpha WebServer (IIM):  206.103.11.47   255.255.255.240
IBM PC (OS/2) [ A ]  :  206.103.11.46   255.255.255.240
IBM PC (OS/2) [ B ]  :  206.103.11.36   255.255.255.240

IBM RS6000           :  192.9.200.15    255.255.255.0                  PC
							    +-------+  +-+
Network diagram is as follows :                             |  AXP  |  | |
							    +-------+  +-+
                     +-------------+     Thinwire               |       |
V   +-------+        |             |----------------------------------------
S   |       |  UTP   |             |
N --|       |--------|   SWITCH    |----            +----------+
L   |       |        |             |                |          |
    +-------+        |             |----------------| RS 6000  |
      Router         +-------------+                |          |
                                                    +----------+



Alpha can ping the PCs A & B. Alpha cannot ping to Router. If Alpha
is connected to UTP port of switch, still it cannot ping to Router. 

If Alpha address is changed to 192.9.200.51 (255.255.255.0)  it can ping &
telnet to RS-6000 sitting at the same physical position.

I have checked the router & switch, there is no filtering defined. Today I
also connected the Alpha directly to router through UTP, still it cannot ping.
This was just to eliminate the Switch.

We configured one PC with DOS and Win 3.11 and Netscape/ PCTCP. The Alpha
address was used in this PC. It could communicate to router and the internet
without any problem. I could ping to the router ethernet port, WAN port and
VSNL. This was from the same physical position in the network where the alpha
was placed.