book

Network Warrior

by Gary A. Donahue

June 2007

Intermediate to advanced

600 pages

18h 19m

English

O'Reilly Media, Inc.

Read now

Unlock full access

Who Should Read This Book

2.1. Hubs
2.2.1. Switch Types2.2.2. Planning a Chassis-Based Switch Installation2.2.2.1. Rack space2.2.2.2. Power2.2.2.3. Cooling2.2.2.4. Installing and removing modules2.2.2.5. Routing cables
3.1. What Is Auto-Negotiation?
4.1. Connecting VLANs
4.2.1. CatOS4.2.2. IOS Using VLAN Database4.2.3. IOS Using Global Commands
5.1. How Trunks Work5.1.1. ISL5.1.2. 802.1Q5.1.3. Which Protocol to Use5.1.4. Trunk Negotiation
5.2.1. IOS5.2.2. CatOS
6.1. VTP Pruning
6.3.1. VTP Domains6.3.1.1. IOS6.3.1.2. CatOS6.3.2. VTP Mode6.3.2.1. IOS6.3.2.2. CatOS6.3.3. VTP Password6.3.3.1. IOS6.3.3.2. CatOS6.3.4. VTP Pruning6.3.4.1. IOS6.3.4.2. CatOS
7.1. Load Balancing
7.2.1. EtherChannel Protocols7.2.2. CatOS Example7.2.3. IOS Example
8.1. Broadcast Storms
8.3.1. How Spanning Tree Works
8.5.1. PortFast8.5.2. BPDU Guard8.5.3. UplinkFast8.5.4. BackboneFast
8.6.1. Duplex Mismatch8.6.2. Unidirectional Links
8.7.1. Use Routing Instead of Switching for Redundancy8.7.2. Always Configure the Root Bridge
9.1. Routing Tables
9.3.1. Host Route9.3.2. Subnet9.3.3. Summary (Group of Subnets)9.3.4. Major Network9.3.5. Supernet (Group of Major Networks)9.3.6. Default Route
10.1. Communication Between Routers
10.4.1. RIP10.4.2. RIPv210.4.3. EIGRP10.4.4. OSPF10.4.5. BGP
11.1. Redistributing into RIP
11.6.1. Route Tags11.6.2. A Real-World Example11.6.2.1. Another method
12.1. GRE Tunnels
13.1. HSRP
14.1. Building a Route Map
14.2.1. Monitoring Policy Routing
15.1. Process Switching
15.2.1. Fast Switching15.2.2. Optimum Switching15.2.3. Cisco Express Forwarding
15.3.1. Process Switching15.3.2. Fast Switching15.3.3. Cisco Express Forwarding
16.1. Configuring SVIs16.1.1. Native Mode (4500, 6500, 3550, 3750)16.1.2. Hybrid Mode (4500, 6500)
17.1. Architecture17.1.1. Buses17.1.2. Enhanced Chassis17.1.3. Supervisors17.1.3.1. MSFC17.1.3.2. PFC17.1.3.3. Models17.1.4. Modules17.1.4.1. Module interaction17.1.4.2. Module types17.1.4.2.1. Ethernet modules17.1.4.2.2. Firewall Services Modules17.1.4.2.3. Content Switch Modules17.1.4.2.4. Network Analysis Modules17.1.4.2.5. Intrusion Detection System Modules17.1.4.2.6. FlexWAN modules17.1.4.2.7. Communication Media Modules
18.1. Stacking
19.1. Introduction and History
20.1. Understanding T1 Duplex
20.3.1. AMI20.3.2. B8ZS
20.4.1. D4/Superframe20.4.2. Extended Superframe (ESF)
20.5.1. Loss of Signal (LOS)20.5.2. Out of Frame (OOF)20.5.3. Bipolar Violation (BPV)20.5.4. CRC620.5.5. Errored Seconds (ES)20.5.6. Extreme Errored Seconds (EES)
20.6.1. Red Alarm20.6.2. Yellow Alarm (RAI)20.6.3. Blue Alarm (AIS)
20.7.1. Loopback Tests20.7.2. Integrated CSU/DSUs
20.8.1. CSU/DSU Configuration20.8.2. CSU/DSU Troubleshooting
21.1. Framing21.1.1. M1321.1.2. C-Bits21.1.3. Clear-Channel DS3 Framing
21.3.1. Clear-Channel DS321.3.2. Channelized DS3
22.1. Ordering Frame-Relay Service
22.4.1. Congestion Avoidance in Frame Relay
22.5.1. Basic Frame Relay with Two Nodes22.5.2. Basic Frame Relay with More Than Two Nodes22.5.3. Frame-Relay Subinterfaces
23.1. Designing Access Lists23.1.1. Wildcard Masks23.1.2. Where to Apply Access Lists23.1.3. Naming Access Lists23.1.4. Top-Down Processing23.1.5. Most-Used on Top23.1.6. Using Groups in PIX ACLs23.1.7. Turbo ACLs23.1.8. Allowing Outbound Traceroute and Ping23.1.9. Allowing MTU Path Discovery Packets
23.2.1. Configuring Port ACLs23.2.2. Configuring Router ACLs23.2.3. Configuring VLAN Maps
23.3.1. Configuring Reflexive Access Lists
24.1. Basic (Non-AAA) Authentication24.1.1. Line Passwords24.1.2. Configuring Local Users24.1.3. PPP Authentication24.1.3.1. PAP24.1.3.1.1. One-way authentication24.1.3.1.2. Two-way authentication24.1.3.1.3. Debugging PPP authentication24.1.3.2. CHAP24.1.3.2.1. One-way authentication24.1.3.2.2. Two-way authentication24.1.3.2.3. Changing the sent hostname
24.2.1. Enabling AAA24.2.2. Configuring Security Server Information24.2.2.1. Default RADIUS and TACACS+ server groups24.2.2.2. Custom groups24.2.3. Creating Method Lists24.2.3.1. Login authentication24.2.3.2. PPP authentication24.2.4. Applying Method Lists
25.1. Best Practices
25.2.1. Another DMZ Example25.2.2. Multiple DMZ Example
26.1. Interfaces and Priorities
26.5.1. Failover Terminology26.5.2. Understanding Failover26.5.3. Configuring Failover26.5.4. Monitoring Failover
26.6.1. NAT Commands26.6.2. NAT Examples26.6.2.1. Simple PAT using the outside interface26.6.2.2. Simple PAT using a dedicated IP address26.6.2.3. Simple PAT with public servers on the inside26.6.2.4. Port redirection26.6.2.5. DMZ
26.7.1. Remote Access26.7.2. Saving Configuration Changes26.7.3. Logging
27.1. Types of Load Balancing
27.2.1. Balancing Algorithms
27.3.1. IOS SLB27.3.1.1. Real servers27.3.1.2. Server farms27.3.1.3. Virtual servers27.3.1.4. Port translation using SLB27.3.2. Content Switch Modules27.3.2.1. Real servers27.3.2.2. Server farms27.3.2.3. Virtual servers27.3.2.4. Port redirection
28.1. Common Tasks
29.1. Types of QoS
29.2.1. Priorities29.2.2. Flavors of QoS
30.1. Determining Requirements30.1.1. Protocols30.1.2. Priorities30.1.3. Determine Bandwidth Requirements
30.2.1. Class Maps30.2.2. Policy Maps30.2.3. Service Policies
31.1. Determining Whether the Network Is Congested
32.1. Configuration
32.3.1. Incorrect Queue Configuration32.3.2. Priority Queue Too Small32.3.3. Priority Queue Too Large32.3.4. Nonpriority Queue Too Small32.3.5. Nonpriority Queue Too Large32.3.6. Default Queue Too Small32.3.7. Default Queue Too Large
33.1. Documentation33.1.1. Requirements Documents33.1.2. Port Layout Spreadsheets33.1.3. IP and VLAN Spreadsheets33.1.4. Bay Face Layouts33.1.5. Power and Cooling Requirements33.1.6. Tips for Network Diagrams
33.3.1. Corporate Networks33.3.1.1. Three-tiered architecture33.3.1.2. Collapsed core—no distribution33.3.1.3. Collapsed core—no distribution or access33.3.1.4. Configuration concerns33.3.1.4.1. Trunks33.3.1.4.2. EtherChannels33.3.1.4.3. Spanning Tree33.3.1.4.4. VTP33.3.1.4.5. VLANs33.3.2. E-Commerce Web Sites33.3.3. Small Networks
34.1. Public Versus Private IP Space
34.5.1. Sequential34.5.2. Divide by Half34.5.3. Reverse Binary
35.1. What Is Accurate Time?
35.3.1. NTP Client35.3.2. NTP Server
36.1. Human Error
36.5.1. Remain Calm36.5.2. Log Your Actions36.5.3. Find Out What Changed36.5.4. Check the Physical Layer First!36.5.5. Assume Nothing; Prove Everything36.5.6. Isolate the Problem36.5.7. Don't Look for Zebras36.5.8. Do a Physical Audit36.5.9. Escalate36.5.10. Troubleshooting in a Team Environment36.5.11. The Janitor Principle
37.1. Maxim #1
38.1. Why Everything Is Messed Up
38.3.1. The Dangers of Upgrading38.3.2. Valid Reasons to Upgrade

Content preview from Network Warrior

MAC Address Table Instability

Another problem caused by a looped environment is MAC address tables (CAM tables in CatOS) being constantly updated. Take the network in Figure 8-3, for example. With all of the switches interconnected, and spanning tree disabled, Switch A will come to believe that the MAC address for the PC directly connected to it is sourced from a different switch. This happens very quickly during a broadcast storm, and, in the rare instances when you see this behavior without a broadcast storm, chances are things are about to get very bad very quickly.

Figure 8-3. MAC address table inconsistencies

With this network in place, and spanning tree disabled, I searched for the MAC address of the PC on Switch A using the show mac-address-table | include 0030.1904.da60 command. I repeated the command as fast as I could and got the following results:

3550-IOS#sho mac-address-table | include 0030.1904.da60
   1    0030.1904.da60    DYNAMIC     Fa0/10
3550-IOS# sho mac-address-table | include 0030.1904.da60
   1    0030.1904.da60    DYNAMIC     Fa0/10
3550-IOS# sho mac-address-table | include 0030.1904.da60
   1    0030.1904.da60    DYNAMIC     Fa0/2
3550-IOS# sho mac-address-table | include 0030.1904.da60
   1    0030.1904.da60    DYNAMIC     Fa0/3
3550-IOS# sho mac-address-table | include 0030.1904.da60
   1    0030.1904.da60    DYNAMIC     Fa0/2
3550-IOS# sho mac-address-table | include 0030.1904.da60

This switch is directly connected to the ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

Start your free trial

Linux Network Administrator's Guide, Second Edition

Publisher Resources

ISBN: 9780596101510Errata Page

Network Warrior

by Gary A. Donahue

MAC Address Table Instability

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.

You might also like

Linux Network Administrator's Guide, Second Edition

Cisco Router Configuration Handbook, Second Edition

Network Routing, 2nd Edition

Large-Scale IP Network Solutions (CCIE Professional Development)

Publisher Resources