- Community Home
- >
- Servers and Operating Systems
- >
- Operating Systems
- >
- Operating System - OpenVMS
- >
- DEC servers and VAX machines on different subnets
Categories
Company
Local Language
Forums
Discussions
Forums
- Data Protection and Retention
- Entry Storage Systems
- Legacy
- Midrange and Enterprise Storage
- Storage Networking
- HPE Nimble Storage
Discussions
Forums
Discussions
Discussions
Discussions
Forums
Discussions
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
- BladeSystem Infrastructure and Application Solutions
- Appliance Servers
- Alpha Servers
- BackOffice Products
- Internet Products
- HPE 9000 and HPE e3000 Servers
- Networking
- Netservers
- Secure OS Software for Linux
- Server Management (Insight Manager 7)
- Windows Server 2003
- Operating System - Tru64 Unix
- ProLiant Deployment and Provisioning
- Linux-Based Community / Regional
- Microsoft System Center Integration
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Discussion Boards
Community
Resources
Forums
Blogs
- Subscribe to RSS Feed
- Mark Topic as New
- Mark Topic as Read
- Float this Topic for Current User
- Bookmark
- Subscribe
- Printer Friendly Page
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 01:24 AM
02-18-2010 01:24 AM
DEC servers and VAX machines on different subnets
For example VAX OpenVMS servers will reside on A.B.C.X network and Assembly Shop DEC servers will be on D.E.F.X subnet (all dec servers ip addresses needs to be changed).
Network team will route dec servers subnet to VAX OpenVMS servers subnet but network communication between VAX OpenVMS servers and DEC servers is not TCP/IP protocol, it is LAT and as i know LAT is non-routable protocol.
Is this network infrastructure applicable ? Is there any infrastructure with this kind of network configuration ?
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 01:58 AM
02-18-2010 01:58 AM
Re: DEC servers and VAX machines on different subnets
But also "(all dec servers ip addresses needs to be changed).", i.e. the decservers are of the newer type supporting TCPIP, so LAT can be replaced by TELNET protocol.
Depending on the specific applications, this can be more or less transparent. If the applications use specific LAT QIOs, then they need change, otherwise "terminal" I/O for both LAT and TELNET are the same.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 01:59 AM
02-18-2010 01:59 AM
Re: DEC servers and VAX machines on different subnets
if you communicate using the LAT protocol between your OpenVMS VAX systems and the DECservers, those two MUST reside in the same 'LAN segment' or the 'LAN segments' must be bridged together regarding the LAT and MOP (DECserver software load) traffic.
There are DECservers, which also do support the TCPIP stack. If you have those or change to those, you should repalce LAT with TCPIP, but this requires changes in your application !
Volker.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 02:04 AM
02-18-2010 02:04 AM
Re: DEC servers and VAX machines on different subnets
If they do not boot from flash memory, but via MOP from the VMS servers, then this has also to be changed to using a different method, namely TFTP. Since the decservers support TCPIP, I also assume they can do TFTP loading. (I only have Lantronix terminal servers, they do TFTP).
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 02:57 AM
02-18-2010 02:57 AM
Re: DEC servers and VAX machines on different subnets
It may help if you were to give the model of the DECservers that you're using and that need to reside on a different subnet. Different models have different features and can have different options (A DECserver 700 can have a flash card installed and (IIRC) can use TFTP or BOOTP to downline load their image, for example.)
Steve
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 02:59 AM
02-18-2010 02:59 AM
Re: DEC servers and VAX machines on different subnets
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 03:24 AM
02-18-2010 03:24 AM
Re: DEC servers and VAX machines on different subnets
DECserver 90M+ should support TCPIP for load via BOOTP/TFTP and for communication with the OpenVMS VAX systems.
You now have to research, whether and how you could change your use of the LTA devices and see, if you can change your applications to use TELNET (TNA devices) to talk to the DECservers.
Volker.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 04:13 AM
02-18-2010 04:13 AM
Re: DEC servers and VAX machines on different subnets
For example, our four node cluster has two nodes at each site with a seperate front end networks or vlans. The bankend is common to all hosts.
Some advice. Licensing on some cisco model switches prevents even non-routable protocols from passing requests to joined switches. This is where one has two physical swithces joined using say an ethernet port.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 05:36 AM
02-18-2010 05:36 AM
Re: DEC servers and VAX machines on different subnets
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 05:53 AM
02-18-2010 05:53 AM
Re: DEC servers and VAX machines on different subnets
And FWIW, the terminal server protocol migration discussed in previous topics is quite correct but also has one big caveat I've not seen mentioned: your software might not work without some updates, as there are low-level differences between LAT and its APIs and telnet and IP and its APIs. Given you're working in a factory floor, it's reasonably likely that you have this code and (having implemented factory floor code, and having done LAT and IP networking and migrations) IP is not necessarily a drop-in replacement for LAT.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 05:59 AM
02-18-2010 05:59 AM
Re: DEC servers and VAX machines on different subnets
No need to use a sledgehammer on your application when a decent network team can set up some network magic on their routers. The problem is getting them to do it.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 06:08 AM
02-18-2010 06:08 AM
Re: DEC servers and VAX machines on different subnets
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-18-2010 09:48 AM
02-18-2010 09:48 AM
Re: DEC servers and VAX machines on different subnets
LAT has some short timeouts.
Purely Personal Opinion
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-19-2010 05:00 AM
02-19-2010 05:00 AM
Re: DEC servers and VAX machines on different subnets
I've known some places where they are...
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-20-2010 01:31 AM
02-20-2010 01:31 AM
Re: DEC servers and VAX machines on different subnets
"subnets" are a TCP/IP V4 entity at layer 3. They are used to break down a TCP/IP V4 address space into manageable pieces. TCP/IP V4 routing is used at layer 3 to exchange data between subnets. That routing mechanism at layer 3 is TCP/IP specific, so it won't pass data for any protocol other than TCP/IP.
"VLANs" are generally a layer 2 entity, so they function at ethernet packet level (layer 2), not at TCP/IP V4 protocol level (layer 3). Most layer 2 VLANs are port based. Packets moving in the infrastructure between switches and co-operating NICs use 802.1Q tagging to associate ethernet packets with the correct VLAN. Bridging is used at layer 2 to exchange data between VLANs and only some switches allow this - many don't, for a whole bunch of reasons. Ethernet packets carry all sorts of different protocols: TCP/IP, DECnet, LAT, MOP, SCS, etc. All those different protocol types are uniquely identified by information in the ethernet packet header or packet payload. RFC1700 has the list of assigned protocol types.
There isn't necessarily a one-to-one correspondence between a "layer 3 TCP/IP V4 subnet" and a "layer 2 VLAN". It often works out that way because frequently the only way to move data between VLANs is to route the packets in the switch. However, there's nothing to stop you having multiple TCP/IP V4 subnets per VLAN, nor is there anything to stop you having a single layer 3 TCP/IP V4 subnet spanning multiple layer 2 VLANs if you bridge between the VLANs at layer2.
As for the DECservers, it depends which type you have and which firmware they have. The early ones don't have BOOTP support for example.
In a non-TCP/IP environment DECservers use a number of on-the-wire layer 2 protocols:
- LAT for serial IO (including 'reverse LAT' for access to printers etc.).
- MOP for down-line loading (which is every time it boots if the DECserver doesn't have local flashRAM, or which is whenever you update the load image firmware if it doesn't have flashRAM, or perhaps when you swap it out due to failure).
- Remote Console Carrier for access to the internal console. Most people confuse this with MOP, but it's another entirely separate layer 2 protocol. It's what gets used when you do a "SET HOST/MOP or NCP CONNECT
Don't forget the second two - they're the ones that most people forget about, then find they can't boot, load or connect remotely to their DECservers after they're moved DECservers to a different VLAN.
In a TCP/IP environment DECservers use several TCP/IP sub-protocols:
- TELNET for serial IO (including TELNETSYM for access to printers)
- BOOTP for down-line loading (every boot or for firmware updates depending whether it has flashRAM)
- LPR/LPD for access to printers (I prefer TELNETSYM myself!)
- TELNET again for access to the internal console. However, think about access to the DECserver when it's not booted and running - you may still need Remote Console Carrier at layer 2 first in order to get to it.
If you're using a DECserver 90M or 900TM then V2.4 onwards works well. It's a bit more fiddly to set up TCP/IP (telnet listener etc.) on the DECserver than to set up LAT. Having a LAT connection at layer 2, along with the Remote Console Carrier at layer 2 is always useful. Don't end up with a VLAN layout that stops you doing this if you can avoid it.
Personally I prefer to segment a LAN infrastructure based on functionality that geographic location within a plant. That requires a bit of care to think through the VLAN design and which NICs connect to which VLANs. That's something else you might want to do - connect multiple NICs from the OpenVMS systems to the network infrastructure, with different NICs running different protocols into different VLANs.
If you want more information, there's a recording of the recent webinar about "Networking with OpenVMS", plus the slides, a Technical Journal article and a bunch of other stuff at http://www.xdelta.co.uk/seminars.
Cheers, Colin (http://www.xdelta.co.uk).
PS: All re-typed from scratch with a text editor after the ITRC system managed to lose everything I typed yesterday. Mutter. Grumble.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
02-20-2010 01:45 AM
02-20-2010 01:45 AM
Re: DEC servers and VAX machines on different subnets
At application level then if you're currently having your applications issue QIOs to LTA devices then you're definitely using LAT and you'll have to change the code to instead make TCP/IP connections to the IP address and TCP/IP port number that corresponds to the DECserver port number once yo've set up the TELNET LISTENER inside the DECserver.
For example, you'd connect to
Cheers, Colin.