Summary

This chapter introduced several families of tools that have proven useful in the context of network testing and monitoring. Packet analyzer, port scanner, ping, and traceroute tools were discussed. If you are looking for a particular tool, see the http://www.freshmeat.net repository. In addition, the generation of special-purpose packets and volume traffic was discussed. This chapter also briefly introduced available UNIX DHCP implementations.

Command Syntax Conventions Chapter 1. Operating System Issues and Features-The Big Picture Why UNIX Is Viable Routing, Forwarding, and Switching Approaches The Evolution of AT&T System V (SVR4) UNIX and 4.4-Lite BSD Derivatives Operating Systems Design Considerations Kernel-Space Modules Versus User-Space Applications Cisco IOS Software OpenBSD FreeBSD NetBSD Linux GNU Hurd/Mach Other Commercial Unices Summary Recommended Reading Endnotes Chapter 2. User-Space Routing Software The GNU Zebra Routing Software The Quagga Project The routed Daemon GateD 3.6 MRT (Multithreaded Routing Toolkit) The Bird Project The XORP Project Multicast Routing Daemons: mrouted and pimd Summary Recommended Reading Chapter 3. Kernel Requirements for a Full-Featured Lab The sysctl Facility IP Forwarding Control and Special Interfaces Ethernet Channel Bonding Multicast Support Firewall and Traffic-Shaping Support The IPv6 Protocol Stack Summary Recommended Reading Chapter 4. Gateway WAN/Metro Interfaces Dial-on-Demand Routing: Analog and ISDN Dialup Wireless Technologies SDH/SONET Powerline Communications Ethernet to the Home/Premises Cisco Long-Reach Ethernet (LRE) Synchronous Serial Interface and PRIs ATM Interfaces Cable Access (Ethernet Interfaces) DSL Access Lab 4-1: Synchronous Serial Connection Setup Exercise 4-1: Frame Relay Point-to-Multipoint Setup Summary Recommended Reading Chapter 5. Ethernet and VLANs Ethernet NICs Hubs, Bridges, and Multilayer Switches Access Ports, Uplinks, Trunks, and EtherChannel Port Groups Alias Interfaces VLAN Configurations A Few Words on Cabling Lab 5-1: FreeBSD Bridge Cluster Lab Lab 5-2: Linux Bridging and the Spanning Tree Lab 5-3: OpenBSD Bridging and Spanning Tree A Few Words on Layer 2 Security Exercise 5-1: Linux/FreeBSD Ethernet Channel Bonding Exercise 5-2: STP Operation Summary Recommended Reading Chapter 6. The Analyzer Toolbox, DHCP, and CDP Terminal Emulation Software Secure Shell Tools Protocol Analyzer Statistical Tools Port Scanners socklist and netstat Ping and Traceroute Combinations DNS Auditing Tools Traffic and Packet Generators Lab 6-1: Using Sniffers-DHCP Example Lab 6-2: UNIX CDP Configuration Summary Recommended Reading Chapter 7. The UNIX Routing and ARP Tables Address Resolution: ARP and RARP Power of the Linux ip, netstat, and route Utilities ARP-Related Tools Lab 7-1: ARP Security Issues Summary Recommended Reading Endnote Chapter 8. Static Routing Concepts Administrative Distance and Metric Classful Routing, VLSM, and CIDR Default Gateways, Default Routes, and Route(s) of Last Resort Route Caches, Routing Tables, Forwarding Tables, and the ISO Context The Near and Far End of a Link The route Command-Adding and Removing Routes Route Cloning Blackholes and Reject/Prohibit Routes Floating Static Routes Equal-Cost Multi-Path (ECMP) Routing Lab 8-1: Interface Metrics, Floating Static Routes, and Multiple Equal-Cost Routes (ECMP) Linux TEQL (True Link Equalizer) Adding Static Routes via Routing Daemons Summary Recommended Reading Endnotes Chapter 9. Dynamic Routing Protocols-Interior Gateway Protocols Interaction with the UNIX Routing Table Classification of Dynamic Routing Protocols From RIP to EIGRP Lab 9-1: RIPv2 Scenario Lab 9-2: RIP Neighbor Granularity Lab 9-3: RIPv2 via GateD Introduction to Link-State Routing Protocols OSPFv2 Lab 9-4: Leaf-Area Design Featuring GateD and Cisco IOS Lab 9-5: Leaf-Area Design Featuring Zebra and Cisco IOS Software ECMP-Manipulating Metric and Distance The Art of Redistribution Lab 9-6: Route Filtering and Redistribution Lab 9-7: OSPF Authentication Route Tagging and Multiple OSPF Processes/Instances IS-IS (Intermediate System-to-Intermediate System) Lab 9-8: IS-IS Flat Backbone Area Lab 9-9: IS-IS Backbone and Leaf Area Lab 9-10: OSPF Point-to-Point Lab Advanced OSPF Features Summary Recommended Reading Endnotes Chapter 10. ISP Connectivity with BGPv4-An Exterior Gateway Path-Vector Routing Protocol for Interdomain Routing Exterior Gateway Protocols: EGP and BGPv4 Internet Exchange Points EBGP and EBGP Multihop IBGP Full Mesh, Route Reflectors, and Confederation Lab 10-1: Route Reflection Lab 10-2: Confederation Lab 10-3: Multi-AS BGP Topology Lab 10-4: BGP with GateD Avoiding Single Points of Failure Route Server and Routing Registries Looking Glasses Routing Policies Special BGP Topics Summary Recommended Reading Chapter 11. VPN Technologies, Tunnel Interfaces, and Architectures The Rationale for Tunnels in Routing Environments The VPNC Concept of VPNs The OSI Stack Perspective Internet, Intranet, and Extranet Terminology IP-IP Tunnel Generic Router Encapsulation (GRE) Tunnel Special Multicast and IPv6 Tunneling (RFC 2473, RFC 3053) Cisco L2F (Layer 2 Forwarding) PPTP (Point-to-Point Tunnel Protocol) L2TP (Layer 2 Tunnel Protocol) Mobile IP User-Space Tunneling IPSec Foundation General Tunnel and Specific IPSec Caveats Advice About IPSec Lab Scenarios Road-Warrior Scenarios (Road Warrior-to-OpenBSD/FreeBSD Gateway with IKE) Dynamic Routing Protocols over Point-to-Point Tunnels-Transparent Infrastructure VPN Summary Recommended Reading Endnotes Chapter 12. Designing for High Availability Increasing Availability Withstanding a (D)DoS Attack Network HA Approaches Simple but Effective Approaches to Server HA DNS Shuffle Records and Round-Robin (DNS RR) Dynamic Routing Protocols Firewall Failover Clustering and Distributed Architectures The Service Routing Redundancy Daemon (SRRD) IPv4/IPv6 Anycast A Few Words About Content Caches and Proxies Load Balancing Cisco HA and Load-Balancing Approaches VRRP OpenBSD CARP IRDP Summary Recommended Reading Endnotes Chapter 13. Policy Routing, Bandwidth Management, and QoS Policy Routing Traffic Shaping, Queuing, Reservation, and Scheduling Linux QoS Layer 3 QoS: IP ToS, Precedence, CoS, IntServ, and DiffServ Codepoints 802.1P/Q Tagging/Priority-QoS at the Data-Link/MAC Sublayer MPLS Exp Field and MPLS Traffic Engineering DiffServ and RSVP/RSVP-TE Implementations for UNIX Cisco IOS QoS and Queuing Architectures UNIX Firewalling Engines and Queuing Summary Recommended Reading Endnote Chapter 14. Multicast Architectures Multicast Deployments Multicast Addresses and Scope Internet Group Management Protocol (IGMP) and Cisco Group Management Protocol (CGMP) mrouted and DVMRP The ip and smcroute Multicast Utilities PIM Operation and Daemons Multicast Open Shortest Path First (MOSPF) Multicast Source Discovery Protocol (MSDP) BGPv4 Multicast Extensions (Multiprotocol BGP, RFC 2858) Multicast Transport Layer Protocols Multicast Invitations and Session Announcements Multicast Security Summary Recommended Reading Chapter 15. Network Address Translation The NAT Foundation-Basic/Traditional NAT NAT, PAT(NAPT), Masquerading, and Port Mapping/Multiplexing Static NAT and ARP/Routing Issues Redirection (Port Forwarding/Relaying or Transparent Proxying) UNIX NAT Approaches NAT-Hostile Protocols Future Developments: NAT-T, MPLS+NAT, Load Balancer NAT Redundancy-Stateful Failover Summary Recommended Reading Appendix A. UNIX Kernel Configuration Files Appendix B. The FreeBSD Netgraph Facility Reasons for Netgraph Recommended Reading