Cisco Cookbook - Brossura

Preface; Organization; What’s in This Book; Conventions; Comments and Questions; Acknowledgments; Chapter 1: Router Configuration and File Management; 1.0 Introduction; 1.1 Configuring the Router via TFTP; 1.2 Saving Router Configuration to Server; 1.3 Booting the Router Using a Remote Configuration File; 1.4 Storing Configuration Files Larger than NVRAM; 1.5 Clearing the Startup Configuration; 1.6 Loading a New IOS Image; 1.7 Booting a Different IOS Image; 1.8 Booting Over the Network; 1.9 Copying an IOS Image to a Server; 1.10 Copying an IOS Image Through the Console; 1.11 Deleting Files from Flash; 1.12 Partitioning Flash; 1.13 Using the Router as a TFTP Server; 1.14 Using FTP from the Router; 1.15 Generating Large Numbers of Router Configurations; 1.16 Changing the Configurations of Many Routers at Once; 1.17 Extracting Hardware Inventory Information; 1.18 Backing Up Router Configurations; Chapter 2: Router Management; 2.0 Introduction; 2.1 Creating Command Aliases; 2.2 Managing the Router’s ARP Cache; 2.3 Tuning Router Buffers; 2.4 Using the Cisco Discovery Protocol; 2.5 Disabling the Cisco Discovery Protocol; 2.6 Using the Small Servers; 2.7 Enabling HTTP Access to a Router; 2.8 Using Static Hostname Tables; 2.9 Enabling Domain Name Service; 2.10 Disabling Domain Name Lookups; 2.11 Specifying a Router Reload Time; 2.12 Creating Exception Dump Files; 2.13 Generating a Report of Interface Information; 2.14 Generating a Report of Routing Table Information; 2.15 Generating a Report of ARP Table Information; 2.16 Generating a Server Host Table File; Chapter 3: User Access and Privilege Levels; 3.0 Introduction; 3.1 Setting Up User IDs; 3.2 Encrypting Passwords; 3.3 Using Better Encryption Techniques; 3.4 Removing Passwords from a Router Configuration File; 3.5 Deciphering Cisco’s Weak Password Encryption; 3.6 Displaying Active Users; 3.7 Sending Messages to Other Users; 3.8 Changing the Number of VTYs; 3.9 Changing VTY Timeouts; 3.10 Restricting VTY Access by Protocol; 3.11 Enabling Absolute Timeouts on VTY Lines; 3.12 Implementing Banners; 3.13 Disabling Banners on a Port; 3.14 Disabling Router Lines; 3.15 Reserving a VTY Port for Administrative Access; 3.16 Restricting Inbound Telnet Access; 3.17 Logging Telnet Access; 3.18 Setting the Source Address for Telnet; 3.19 Automating the Login Sequence; 3.20 Using SSH for Secure Access; 3.21 Changing the Privilege Level of IOS Commands; 3.22 Defining Per-User Privileges; 3.23 Defining Per-Port Privileges; Chapter 4: TACACS+; 4.0 Introduction; 4.1 Authenticating Login IDs from a Central System; 4.2 Restricting Command Access; 4.3 Losing Access to the TACACS+ Server; 4.4 Disabling TACACS+ Authentication on a Particular Line; 4.5 Capturing User Keystrokes; 4.6 Logging System Events; 4.7 Setting the IP Source Address for TACACS+ Messages; 4.8 Obtaining Free TACACS+ Server Software; 4.9 Sample Server Configuration Files; Chapter 5: IP Routing; 5.0 Introduction; 5.1 Finding an IP Route; 5.2 Finding Types of IP Routes; 5.3 Converting Different Mask Formats; 5.4 Using Static Routing; 5.5 Floating Static Routes; 5.6 Using Policy-Based Routing to Route Based on Source Address; 5.7 Using Policy-Based Routing to Route Based on Application Type; 5.8 Examining Policy-Based Routing; 5.9 Changing Administrative Distances; 5.10 Routing Over Multiple Paths with Equal Costs; Chapter 6: RIP; 6.0 Introduction; 6.1 Configuring RIP Version 1; 6.2 Filtering Routes with RIP; 6.3 Redistributing Static Routes into RIP; 6.4 Redistributing Routes Using Route Maps; 6.5 Creating a Default Route in RIP; 6.6 Disabling RIP on an Interface; 6.7 Unicast Updates for RIP; 6.8 Applying Offsets to Routes; 6.9 Adjusting Timers; 6.10 Configuring Interpacket Delay; 6.11 Enabling Triggered Updates; 6.12 Increasing the RIP Input Queue; 6.13 Configuring RIP Version 2; 6.14 Enabling RIP Authentication; 6.15 RIP Route Summarization; 6.16 Route Tagging; Chapter 7: EIGRP; 7.0 Introduction; 7.1 Configuring EIGRP; 7.2 Filtering Routes with EIGRP; 7.3 Redistributing Routes into EIGRP; 7.4 Redistributing Routes into EIGRP Using Route Maps; 7.5 Creating a Default Route in EIGRP; 7.6 Disabling EIGRP on an Interface; 7.7 EIGRP Route Summarization; 7.8 Adjusting EIGRP Metrics; 7.9 Adjusting Timers; 7.10 Enabling EIGRP Authentication; 7.11 Logging EIGRP Neighbor State Changes; 7.12 Limiting EIGRP’s Bandwidth Utilization; 7.13 EIGRP Stub Routing; 7.14 Route Tagging; 7.15 Viewing EIGRP Status; Chapter 8: OSPF; 8.0 Introduction; 8.1 Configuring OSPF; 8.2 Filtering Routes in OSPF; 8.3 Adjusting OSPF Costs; 8.4 Creating a Default Route in OSPF; 8.5 Redistributing Static Routes into OSPF; 8.6 Redistributing External Routes into OSPF; 8.7 Manipulating DR Selection; 8.8 Setting the OSPF RID; 8.9 Enabling OSPF Authentication; 8.10 Selecting the Appropriate Area Types; 8.11 Summarizing Routes in OSPF; 8.12 Disabling OSPF on Certain Interfaces; 8.13 OSPF Route Tagging; 8.14 Logging OSPF Adjacency Changes; 8.15 Adjusting OSPF Timers; 8.16 Viewing OSPF Status with Domain Names; 8.17 Debugging OSPF; Chapter 9: BGP; 9.0 Introduction; 9.1 Configuring BGP; 9.2 Using eBGP Multihop; 9.3 Adjusting the Next-Hop Attribute; 9.4 Connecting to Two ISPs; 9.5 Connecting to Two ISPs with Redundant Routers; 9.6 Restricting Networks Advertised to a BGP Peer; 9.7 Adjusting Local Preference Values; 9.8 Load Balancing; 9.9 Removing Private ASNs from the AS Path; 9.10 Filtering BGP Routes Based on AS Paths; 9.11 Reducing the Size of the Received Routing Table; 9.12 Summarizing Outbound Routing Information; 9.13 Prepending ASNs to the AS Path; 9.14 Redistributing Routes with BGP; 9.15 Using Peer Groups; 9.16 Authenticating BGP Peers; 9.17 Putting It All Together; Chapter 10: Frame Relay; 10.0 Introduction; 10.1 Setting Up Frame Relay with Point-to-Point Subinterfaces; 10.2 Adjusting LMI Options; 10.3 Setting Up Frame Relay with Map Statements; 10.4 Using Multipoint Subinterfaces; 10.5 Configuring Frame Relay SVCs; 10.6 Simulating a Frame Relay Cloud; 10.7 Compressing Frame Relay Data on a Subinterface; 10.8 Compressing Frame Relay Data with Maps; 10.9 Viewing Frame Relay Status Information; Chapter 11: Queueing and Congestion; 11.0 Introduction; 11.1 Fast Switching and CEF; 11.2 Setting the DSCP or TOS Field; 11.3 Using Priority Queueing; 11.4 Using Custom Queueing; 11.5 Using Custom Queues with Priority Queues; 11.6 Using Weighted Fair Queueing; 11.7 Using Class-Based Weighted Fair Queueing; 11.8 Controlling Congestion with WRED; 11.9 Using RSVP; 11.10 Using Generic Traffic Shaping; 11.11 Using Frame-Relay Traffic Shaping; 11.12 Using Committed Access Rate; 11.13 Implementing Standards-Based Per-Hop Behavior; 11.14 Viewing Queue Parameters; Chapter 12: Tunnels and VPNs; 12.0 Introduction; 12.1 Creating a Tunnel; 12.2 Tunneling Foreign Protocols in IP; 12.3 Tunneling with Dynamic Routing Protocols; 12.4 Viewing Tunnel Status; 12.5 Creating an Encrypted Router-to-Router VPN; 12.6 Generating RSA Keys; 12.7 Creating a Router-to-Router VPN with RSA Keys; 12.8 Creating a VPN Between a Workstation and a Router; 12.9 Check IPSec Protocol Status; Chapter 13: Dial Backup; 13.0 Introduction; 13.1 Automating Dial Backup; 13.2 Using Dialer Interfaces; 13.3 Using an Async Modem on the AUX Port; 13.4 Using Backup Interfaces; 13.5 Using Dialer Watch; 13.6 Ensuring Proper Disconnection; 13.7 View Dial Backup Status; 13.8 Debugging Dial Backup; Chapter 14: NTP and Time; 14.0 Introduction; 14.1 Timestamping Router Logs; 14.2 Setting the Time; 14.3 Setting the Time Zone; 14.4 Adjusting for Daylight Saving Time; 14.5 Synchronizing the Time on All Routers (NTP); 14.6 Configuring NTP Redundancy; 14.7 Setting the Router as the NTP Master for the Network; 14.8 Changing NTP Synchronization Periods; 14.9 Using NTP to Send Periodic Broadcast Time Updates; 14.10 Using NTP to Send Periodic Multicast Time Updates; 14.11 Enabling and Disabling NTP Per Interface; 14.12 NTP Authentication; 14.13 Limiting the Number of Peers; 14.14 Restricting Peers; 14.15 Setting the Clock Period; 14.16 Checking the NTP Status; 14.17 Debugging NTP; Chapter 15: DLSw; 15.0 Introduction; 15.1 Configuring DLSw; 15.2 Using DLSw to Bridge Between Ethernet and Token Ring; 15.3 Converting Ethernet and Token Ring MAC Addresses; 15.4 Configuring SDLC; 15.5 Configuring SDLC for Multidrop Connections; 15.6 Using STUN; 15.7 Using BSTUN; 15.8 Controlling DLSw Packet Fragmentation; 15.9 Tagging DLSw Packets for QoS; 15.10 Supporting SNA Priorities; 15.11 DLSw+ Redundancy and Fault Tolerance; 15.12 Viewing DLSw Status Information; 15.13 Viewing SDLC Status Information; 15.14 Debugging DSLw; Chapter 16: Router Interfaces and Media; 16.0 Introduction; 16.1 Viewing Interface Status; 16.2 Configuring Serial Interfaces; 16.3 Using an Internal T1 CSU/DSU; 16.4 Using an Internal ISDN PRI Module; 16.5 Using an Internal 56Kbps CSU/DSU; 16.6 Configuring an Async Serial Interface; 16.7 Configuring ATM Subinterfaces; 16.8 Setting Payload Scrambling on an ATM Circuit; 16.9 Configuring Ethernet Interface Features; 16.10 Configuring Token Ring Interface Features; 16.11 Connecting VLAN Trunks With ISL; 16.12 Connecting VLAN Trunks with 802.1Q; Chapter 17: Simple Network Management Protocol; 17.0 Introduction; 17.1 Configuring SNMP; 17.2 Extracting Router Information via SNMP Tools; 17.3 Recording Important Router Information for SNMP Access; 17.4 Extracting Inventory Information from a List of Routers with SNMP; 17.5 Using Access Lists to Protect SNMP Access; 17.6 Logging Unauthorized SNMP Attempts; 17.7 Limiting MIB Access; 17.8 Using SNMP to Modify a Router’s Running Configuration; 17.9 Using SNMP to Copy a New IOS Image; 17.10 Using SNMP to Perform Mass Configuration Changes; 17.11 Preventing Unauthorized Configuration Modifications; 17.12 Making Interface Table Numbers Permanent; 17.13 Enabling SNMP Traps and Informs; 17.14 Sending syslog Messages as SNMP Traps and Informs; 17.15 Setting SNMP Packet Size; 17.16 Setting SNMP Queue Size; 17.17 Setting SNMP Timeout Values; 17.18 Disabling Link Up/Down Traps per Interface; 17.19 Setting the IP Source Address for SNMP Traps; 17.20 Using RMON to Send Traps; 17.21 Enabling SNMPv3; 17.22 Using SAA; Chapter 18: Logging; 18.0 Introduction; 18.1 Enabling Local Router Logging; 18.2 Setting the Log Size; 18.3 Clearing the Router’s Log; 18.4 Sending Log Messages to Your Screen; 18.5 Using a Remote Log Server; 18.6 Enabling Syslog on a Unix Server; 18.7 Changing the Default Log Facility; 18.8 Restricting What Log Messages Are Sent to the Server; 18.9 Setting the IP Source Address for Syslog Messages; 18.10 Logging Router Syslog Messages in Different Files; 18.11 Maintaining Syslog Files on the Server; 18.12 Testing the Syslog Sever Configuration; 18.13 Preventing the Most Common Messages from Being Logged; 18.14 Rate-Limiting Syslog Traffic; Chapter 19: Access Lists; 19.0 Introduction; 19.1 Filtering by Source or Destination IP Address; 19.2 Adding a Comment to an ACL; 19.3 Filtering by Application; 19.4 Filtering Based on TCP Header Flags; 19.5 Restricting TCP Session Direction; 19.6 Filtering Multiport Applications; 19.7 Filtering Based on DSCP and TOS; 19.8 Logging when an Access List Is Used; 19.9 Logging TCP Sessions; 19.10 Analyzing ACL Log Entries; 19.11 Using Named and Reflexive Access Lists; 19.12 Dealing with Passive Mode FTP; 19.13 Using Context-Based Access Lists; Chapter 20: DHCP; 20.0 Introduction; 20.1 Using IP Helper Addresses for DHCP; 20.2 Limiting the Impact of IP Helper Addresses; 20.3 Using DHCP to Dynamically Configure Router IP Addresses; 20.4 Dynamically Allocating Client IP Addresses via DHCP; 20.5 Defining DHCP Configuration Options; 20.6 Defining DHCP Lease Periods; 20.7 Allocating Static IP Addresses with DHCP; 20.8 Configuring a DHCP Database Client; 20.9 Configuring Multiple DHCP Servers per Subnet; 20.10 Showing DHCP Status; 20.11 Debugging DHCP; Chapter 21: NAT; 21.0 Introduction; 21.1 Configuring Basic NAT Functionality; 21.2 Allocating External Addresses Dynamically; 21.3 Allocating External Addresses Statically; 21.4 Translating Some Addresses Statically and Others Dynamically; 21.5 Translating in Both Directions Simultaneously; 21.6 Rewriting the Network Prefix; 21.7 Adjusting NAT Timers; 21.8 Changing TCP Ports for FTP; 21.9 Checking NAT Status; 21.10 Debugging NAT; Chapter 22: Hot Standby Router Protocol; 22.0 Introduction; 22.1 Configuring Basic HSRP Functionality; 22.2 Using HSRP Preempt; 22.3 Making HSRP React to Problems on Other Interfaces; 22.4 Load Balancing with HSRP; 22.5 Redirecting ICMP with HSRP; 22.6 Manipulating HSRP Timers; 22.7 Using HSRP on a Token Ring Network; 22.8 HSRP SNMP Support; 22.9 Increasing HSRP Security; 22.10 Showing HSRP State Information; 22.11 Debugging HSRP; Chapter 23: IP Multicast; 23.0 Introduction; 23.1 Configuring Basic Multicast Functionality with PIM-DM; 23.2 Routing Multicast Traffic with PIMSM and BSR; 23.3 Routing Multicast Traffic with PIM-SM and Auto-RP; 23.4 Configuring Routing for a Low Frequency Multicast Application; 23.5 Configuring CGMP; 23.6 Static Multicast Routes and Group Memberships; 23.7 Routing Multicast Traffic with MOSPF; 23.8 Routing Multicast Traffic with DVMRP; 23.9 DVMRP Tunnels; 23.10 Controlling Multicast Scope with TTL; 23.11 Using Administratively Scoped Addressing; 23.12 Exchanging Multicast Routing Information with MBGP; 23.13 Using MSDP to Discover External Sources; 23.14 Converting Broadcasts to Multicasts; 23.15 Showing Multicast Status; 23.16 Debugging Multicast Routing; External Software Packages; A.1 Perl; A.2 Expect; A.3 NET-SNMP; A.4 PuTTY; A.5 OpenSSH; A.6 Ethereal; IP Precedence, TOS, and DSCP Classifications; B.1 Combining TOS and IP Precedence to Mimic DSCP; B.2 RSVP; B.3 Queueing Algorithms; B.4 Dropping Packets and Congestion Avoidance; Colophon;