© 2004 IBM Corporation IBM ^ z/VM Module 11: Networking

© 2004 IBM Corporation

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z/VM Module 11: Networking


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Objectives

Describe TCP/IP setup in conjunction with z/VM Understand the fundamental concepts of computer networks List and describe the four different protocols of the TCP/IP

architecture and their purpose Describe the purpose and function of routing


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Objectives continued

List the reasons for using a routing table and the major differences between these dynamic routing table formats:

RIP-1 RIP-2 OSPF

List and describe the four different types of internet addressing: Network address format Broadcast address format Multicast address format Subnetwork address format


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Explain the major differences between the fiber connectors ESCON and FICON

Show and describe how a Parallel Sysplex is set up and the enhancements it can provide

Describe the devices and protocols that are available when configuring your network, including:

QDIO (can be configured into guest LANs with z/VM 4.3) OSA-Express and OSA-2 HiperSockets (can be configured into guest LANs)


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Describe how VIPA is capable of adding another level of protection against network failures, along with recovery

Discuss the four major commands needed to monitor your TCP/IP network:

NETSTAT RPCINFO PING TRACERTE


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z/VM and TCP/IP


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Computer Network

Is a group of connected nodes that are used for data communication Its configuration consists of data processing devices, software, and

transmission media that are linked for information interchange Nodes are the functional units, located at the points of connection

among the data circuits Some of the more common network architectures, or protocols, used

today are OSI, TCP/IP, SNA, and ISDN.


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Internet Addressing


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OSI Model


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Internet Environment

The internet is a logical collection of networks supported by: Gateways

Routers

Bridges

Hosts

Various layers of protocols Protocols specify a set of rules and formats required to exchange and

transfer packets of information.


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Internet Environment continued

Internet – a worldwide network of computer networks Intranet – a private network, usually used within a closed

environment supporting one company Extranet – a private network that uses the Internet protocols

and the public telecommunication system to share part of a company’s business information with outside vendors


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TCP/IP Architecture


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TCP/IP Architecture continued


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Routing: Overview

It is the method by which a host or a gateway decides where to send a datagram.

There are two kinds of routing that are involved in communication within an internet:

Direct routing is used when the source and destination nodes are in the same logical network within an internet.

Indirect routing is used when the source and destination nodes are on different networks within an internet, where source nodes send packets to a gateway or router on the same network using direct routing and the packets are forwarded through intermediate gateways until the destination is reached


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Routing: Overview - Terms

Important terms are: Router Gateway Daemon Network Interface Network Subnetwork FTP TELNET


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Routing Tables


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Routing Table Management

The most complex task in configuring the TCP/IP network routing is establishing the routing tables.

Static routing requires you to manually configure the routing tables yourself.

With dynamic routing, information is automatically exchanged among various routers in your network, which allows IP address to be found when a new IP host come online.

The more common interior gateway protocols in dynamic routing are: RIP-1 RIP-2


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Dynamic Routing: RIP Version 1


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Dynamic Routing: RIP Version 2


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OSPF

Open Shortest Path First OSPF differs from RIP in these ways:

No limitations on the hop count

Intelligent use of VLSM

Uses IP multicast to send link-state updates

Better convergence

Better load balancing

Allows for routing authentication


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BGP

Border Gateway Protocol is an interautonomous system routing protocol.

The attributes that BGP uses in the route selection process include: Weight Local preference Multi-exit discriminator Origin AS_Path Next hop Community


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Virtual IP Addressing (VIPA)


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Internet Addressing and Network Address Format


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Internet Addressing: Broadcast, Multicast, and Subnetwork

TCP/IP uses IP broadcasting to send datagrams to all the TCP/IP host on a network or subnetwork

Multicasting also sends datagrams, but you will only receive the datagrams if the host is signed up to listen for the particular IP multicast address; otherwise it is discarded

The subnetwork capability of TCP/IP divides a single network into multiple logical networks


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Networking Device Options


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ESCON(Enterprise System Connectivity)

The high-speed fiber optic architecture first available on ES/9000 and many other peripherals

Originally used LEDs and worked at 10MBps over 3 km stretches

A laser version announced in 1991 is capable of working at greater distances

Was replaced by FICON in 1998, though still available


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FICON (Fibre Connections)


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FICON CTC


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Parallel Sysplex Cluster Technology

The zSeries Parallel Sysplex cluster contains innovative multi-system data sharing technology.

This allows direct, concurrent read/write access to shared data from all processing modes in the configuration without sacrificing performance or data integrity.

The Parallel Sysplex manages this multi-system environment, providing these benefits:

Continuous availability Dynamic workload balancing Application compatibility


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Parallel Sysplex Cluster Technology continued

Within a Parallel Sysplex cluster it is possible to construct a parallel processing environment with no single point of failure.

The features of the Parallel Sysplex solution that contribute to increased availability and also help eliminate some system management tasks are:

Workload manager

Sysplex failure manager

Automatic restart manager

Cloning


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Queued Direct I/O (QDIO)


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Open System Adapters


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OSA-2

An integrated hardware feature that allows a zSeries 900 to provide industry-standard connectivity directly to clients on local area networks.

The clients on the attached LAN can use the TCP/IP or the SNA/APPN protocol, or both.

Ethernet, Fast Ethernet, and ATM LAN attachment to the z900 is supported by OSA-Express, but not by OSA-2.


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OSA-Express Characteristics


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Virtual IP Addressing


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What Are HiperSockets and What Benefits Do They Provide?

They provide very fast TCP/IP communications between servers running in different LPARs on a zSeries CEC.

HiperSockets uses internal Queued Input/Output (iQDIO) at memory speeds to pass traffic between the virtual servers.

Important aspects of HiperSockets include: They can be used to communicate among consolidated servers

in a single processor They can be customized to accommodate varying traffic sizes Since there is no server-to-service traffic outside the zSeries

CEC, they provide a much higher level of network availability, security, simplicity, performance, and cost effectiveness


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How Do HiperSockets Work?


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HiperSockets Usage Example


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HiperSockets Microcode Functions

HiperSockets implementation is based on the OSA-Express QDIO protocol, hence HiperSockets is also called internal iQDIO.

TCP/IP stacks are addressed by inbound data queue addresses instead of MAC addresses.

The microcode maintains a lookup table of IP addresses for each HiperSockets.

The controlling operating system that performs I/O processing is identical to OSA-Express in QDIO mode.


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z/VM Before Guest LANs


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z/VM Guest LAN


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z/VM’s Virtual Switch

z./VM Virtual Switch is an extension of the Guest LAN simulated networking function.

VSWITCH operates almost exactly the same as a z/VM 4.3 QDIO Guest LAN, with two important exceptions:

Direct external network access via OSA Express

IEEE 802.1Q VLAN Support


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Network Consolidation Using the Virtual Switch

A Virtual Switch is capable of bridging a z/VM Guest LAN to an associated real LAN connected by an OSA-Express adapter.

Virtual Switch operates as part of the z/VM CP and is not a separate guest machine.

Virtual Switch support is also used to manage the z/VM VLAN environment.


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The Overall TCP/IP Setup


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Monitoring the TCP/IP Network - NETSTAT


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Monitoring the TCP/IP Network – NETSTAT continued


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NETSTAT Examples


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RPCINFO Command


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PING Command


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TRACERTE Command


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TRACERTE Command Usage Notes

To use the TRACERTE command, you must be a privileged TCP/IP user.

The range of port numbers that the TRACERTE command uses is normally invalid; however you can change the starting port number for this range if the target host is using a nonstandard UPD port.

The TRACERTE function will give unpredictable results if the TCP/IP stack is configured to use equal-cost multi-path support.


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Conclusion

Important topics discussed in this module:

TCP/IP Protocols and Functions

– Link Protocols– Networking Protocols– Transport Protocols– Application Protocols

Routing capabilitiesInternet Addressing

– Networking address format– Broadcast address format– Multicast address format– Subnetwork address format

Important devices discussed in this module:

ESCONFICON and FICON CTCParallel SysplexQueued Direct I/OOSA-Express and OSA-2Virtual IP AddressingHiperSocketsGuest LANs

Commands that are used to monitor the networking devices are:

NETSTATRPCINFOPINGTRACERTE


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Glossary

Channel-to-channel Adapter (CTCA) – an adapter that cross-connect a pair of channels between systems to allow for point-to-point communications between two systems.

Domain Name Server (DNS) -- the distributed data system (directory) used to map domain names to IP addresses.

ESCON – Enterprise System Connection; a set of IBM products and services that provide a dynamically connected environment within an enterprise based upon fiber connections.

FICON – Fiber Connectivity; a high-speed I/O interface for mainframe computer connections to storage devices. This new architecture is about eight times as efficient as ESCON.

File Transfer Protocol (FTP): -- generally used for file transfers from TCP/IP systems, it originated on the internet.


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Glossary

Network File System (NFS): – a set of UNIX protocols for file sharing across a LAN; built on top of Ethernet and TCP/IP. Has became a standard in the UNIX environment.

NFS Client – New to z/VM, NFS Client is integrated into both CMS and the priced, optional TCP/IP feature of z/VM.

Socket – an end point provided by the transport service of a network for communications between processes or application programs.

Secure Socket Layer (SSL): – a security protocol that provides communication privacy; SSL enables client/server applications to communicate in a way that is designed to prevent eavesdropping, tampering, and message forgery.

Virtual Private Network (VPN): – a network comprised of one or more secure IP tunnels connecting two or more networks.


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References

IBM eserver zSeries 900: OSA-Express Overview. October 2001.

TCP/IP Solutions for VM/ESA. 1999.

White, Bill, Rama Ayyar, and Velibor Uskokovic. IBM Redbook: zSeries HiperSockets. May 2002

Documents

© 2004 IBM Corporation IBM ^ z/VM Module 11: Networking