Front cover Advanced Networking Concepts Applied Using Linux on IBM System z Understand the IBM z/VM failover concepts Build a practical network solution using Linux on System z Configure routers and switches for redundancy Lydia Parziale Ben Louie Eric Marins Tiago Nunes dos Santos Srivatsan Venkatesan ibm.com/redbooks International Technical Support Organization Advanced Networking Concepts Applied Using Linux on IBM System z February 2012 SG24-7995-00 Note: Before using this information and the product it supports, read the information in “Notices” on page vii. First Edition (February 2012) This edition applies to Red Hat Enterprise Linux versions 5.6 and 6.1, SUSE Linux Enterprise Server 11 SP1. © Copyright International Business Machines Corporation 2012. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . vii Trademarks . viii Preface . ix The team who wrote this book . ix Now you can become a published author, too! . .x Comments welcome. .x Stay connected to IBM Redbooks . xi Chapter 1. Networking concepts overview . 1 1.1 Virtual local area network . 2 1.2 VLAN trunking . 3 1.2.1 IEEE 802.1Q protocol . 3 1.2.2 Native VLAN . 4 1.3 Link aggregation . 4 1.4 Virtual switch . 6 1.5 Virtual network interface controller . 7 1.6 Ethernet autonegotiation . 7 1.7 Maximum transmission unit. 10 1.8 Spanning Tree Protocol . 11 1.9 Load balancing . 11 1.9.1 Layer 2 load sharing . 11 1.9.2 Layer 3 load sharing . 12 Chapter 2. Linux on System z networking overview . 15 2.1 Basic concepts . 16 2.2 Overview of virtualization and networking. 16 2.2.1 Guest LANs / HiperSockets . 17 2.2.2 Virtual switches . 17 2.2.3 Setting the vmcp module to be loaded during boot. 21 2.2.4 Modifying VSWITCH from layer 3 to layer 2 . 22 2.2.5 The qeth driver . 23 2.3 Important Linux network files . 24 2.3.1 SUSE Linux Enterprise Server 11 configuration files . 24 2.3.2 Red Hat configuration files . 27 2.3.3 How to add a qeth device manually . 27 2.4 Network problem determination . 28 2.4.1 Inter-User Communication Vehicle . 28 2.4.2 The qeth interface is not online. 29 2.4.3 Layer 2 mismatch in the VSWITCH configuration. 29 Chapter 3. Linux networking tools . 31 3.1 Network setup . 32 3.1.1 Managing network interface parameters. 32 3.1.2 Names. 35 3.1.3 Routing . 36 3.1.4 Applications management. 36 3.2 Monitoring, diagnosing, and measuring the performance of the network . 38 3.2.1 SSH and secure connections . 41 © Copyright IBM Corp. 2012. All rights reserved. iii 3.2.2 Basic network protocols . 42 3.2.3 Monitoring . 43 3.2.4 Diagnosing . 44 3.2.5 Advanced diagnostic procedures . 48 Chapter 4. Using channel bonding interfaces . 51 4.1 Overview . 52 4.2 Setting up channel bonding. 52 4.2.1 Troubleshooting . 58 Chapter 5. High availability with Linux on System z . 61 5.1 Basic concepts . 62 5.2 Definitions of high availability . 63 5.3 High availability configurations . 63 5.3.1 Active / standby. 63 5.3.2 Active / active . 64 5.4 Introduction to Tivoli System Automation . 64 5.5 Tivoli System Automation implementation for IBM WebSphere MQ. 64 5.5.1 Tivoli System Automation specifications per node cluster . 65 5.5.2 Configuring Tivoli System Automation for IBM WebSphere MQ. 67 5.5.3 Special commands to work with a Tivoli System Automation resource . 75 5.5.4 Operational commands. 75 Chapter 6. Building a practical redundant solution. 77 6.1 Lab environment configuration . 78 6.2 IBM J48E switch configuration . 80 6.2.1 Virtual Chassis setup . 80 6.2.2 VLANs and VLAN interfaces configuration . 81 6.2.3 Aggregated Ethernet interface configuration . 83 6.2.4 MTU configuration. 84.