Summarizing Routes in OSPF
Problem
You want to minimize the size of a backbone routers link-state database by summarizing the routes sent to the backbone area.
Solution
Summarize the routes that are flooded into the backbone area by the ABR:
[edit protocols ospf] aviva@RouterJ# set area 0.0.0.3 area-range 10.0.0.0/16
Discussion
OSPF route summarization aggregates routes sent by nonbackbone areas to the backbone routers so that the size of their link-state databases is reduced. In this recipe, the networks in Area 0.0.0.3 are 10.0.8.1/28, 10.0.8.2/28, 10.0.13.1/28, and 10.0.13.2/28 (see Figure 12-3), which can be summarized as 10.0.0.0/24.
If we check on one of the backbone routers before configuring route summarization, we see four Type 3 (Summary) LSAs in the link-state database:
aviva@RouterG> show ospf database OSPF link state database, area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.17.1 192.168.17.1 0x80000189 16 0x2 0x926e 60 Router 192.168.18.1 192.168.18.1 0x80000124 2601 0x2 0x97cd 60 Router *192.168.19.1 192.168.19.1 0x8000009c 126 0x2 0xb4c7 48 Network *10.0.0.1 192.168.19.1 0x80000090 726 0x2 0x9aae 32 Network *10.0.1.2 192.168.19.1 0x80000090 426 0x2 0x92b3 32 Network 10.0.2.1 192.168.18.1 0x8000009b 1651 0x2 0x6cd1 32 Summary 10.0.8.0 192.168.17.1 0x80000009 16 0x2 0xa62f 28 Summary 10.0.13.0 192.168.17.1 0x80000002 16 0x2 0xa8c 28 Summary 192.168.15.1 192.168.17.1 0x80000002 16 0x2 0x1510 28 Summary 192.168.16.1 192.168.17.1 0x80000002 16 0x2 0x7de7 28 ASBRSum 192.168.15.1 192.168.17.1 0x80000002 16 0x2 0x71d 28 OSPF AS SCOPE link state database Type ID Adv Rtr Seq Age Opt Cksum Len Extern 10.0.15.0 192.168.15.1 0x80000001 161 0x2 0x3f01 36 Extern 172.19.121.0 192.168.15.1 0x80000001 161 0x2 0x859a 36 Extern 172.19.121.0 192.168.17.1 0x80000003 472 0x2 0x73a8 36 Extern 192.168.15.1 192.168.15.1 0x80000001 161 0x2 0x6d9 36 Extern 192.168.17.1 192.168.17.1 0x80000003 240 0x2 0xddfb 36
After the ABR for Area 0.0.0.3 begins aggregating the routes, the number of Type 3 LSAs sent to the backbone area decreases to three, and two LSAs from that area, 10.0.8.0 and 10.0.13.0, are combined into one, 10.0.0.0:
aviva@RouterG> show ospf database OSPF link state database, area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 192.168.17.1 192.168.17.1 0x8000018c 20 0x2 0x8c71 60 Router 192.168.18.1 192.168.18.1 0x80000124 2842 0x2 0x97cd 60 Router *192.168.19.1 192.168.19.1 0x8000009c 367 0x2 0xb4c7 48 Network *10.0.0.1 192.168.19.1 0x80000091 67 0x2 0x98af 32 Network *10.0.1.2 192.168.19.1 0x80000090 667 0x2 0x92b3 32 Network 10.0.2.1 192.168.18.1 0x8000009b 1892 0x2 0x6cd1 32 Summary 10.0.0.0 192.168.17.1 0x80000001 20 0x2 0xf59f 28 Summary 192.168.15.1 192.168.17.1 0x80000005 20 0x2 0xf13 28 Summary 192.168.16.1 192.168.17.1 0x80000005 20 0x2 0x77ea 28 ASBRSum 192.168.15.1 192.168.17.1 0x80000005 20 0x2 0x120 28 OSPF AS SCOPE link state database Type ID Adv Rtr Seq Age Opt Cksum Len Extern 10.0.15.0 192.168.15.1 0x80000002 10 0x2 0x3d02 36 Extern 172.19.121.0 192.168.15.1 0x80000001 402 0x2 0x859a 36 Extern 172.19.121.0 192.168.17.1 0x80000004 117 0x2 0x71a9 36 Extern 192.168.15.1 192.168.15.1 0x80000001 402 0x2 0x6d9 36 Extern 192.168.17.1 192.168.17.1 0x80000003 481 0x2 0xddfb 36
Router Configuration and File Management
- Introduction
- Configuring the Router for the First Time
- Configuring the Router from the CLI
- Getting Exclusive Access to Configure the Router
- Displaying the Commands to Recreate a Configuration
- Including Comments in the Configuration
- Checking the Syntax of the Configuration
- Activating the Router Configuration
- Debugging a Failed Commit
- Exiting Configuration Mode
- Keeping a Record of Configuration Changes
- Determining What Changes You Have Made to the Configuration
- Configuring the Router by Copying a File from a Server
- Configuring the Router by Copying Text from a Terminal Window
- Backing Up the Routers Configuration
- Scheduling the Activation of a Configuration
- Provisionally Activating a Configuration
- Loading a Previous Router Configuration
- Creating an Emergency Rescue Configuration
- Backing Up Filesystems on M-Series and T-Series Routers
- Backing Up Filesystems on J-Series Routers
- Restoring a Backed-Up Filesystem
- Installing a Different Software Release on M-Series and T-Series Routers
- Installing a Different Software Release on J-Series Routers
- Creating an Emergency Boot Disk
- Gathering Software Version Information
- Gathering Hardware Inventory Information
- Finding Out How Long the Router Has Been Up
- Gathering Information Before Contacting Support
- Managing Routers with Similar Configurations
- Managing Redundant Routing Engines
- Using the Second Routing Engine to Upgrade to a New Software Version
Basic Router Security and Access Control
- Basic Router Security and Access Control
- Introduction
- Allowing Access to the Router
- Controlling Root Authentication
- Logging In to the Routers Console
- Setting the Login Authentication Methods
- Setting Up Login Accounts on the Router
- Changing the Format of Plain-Text Passwords
- Changing the Plain-Text Password Encryption Method
- Creating a Login Account for Remote Authentication
- Creating a Group Login Account
- Customizing Account Privileges
- Creating a Privilege Class that Hides Encrypted Passwords
- Setting Up RADIUS User Authentication
- Setting Up TACACS+ User Authentication
- Restricting Inbound SSH and Telnet Access
- Setting the Source Address for Telnet Connections
- Creating a Login Banner
- Finding Out Who Is Logged In to the Router
- Logging Out of the Router
- Forcibly Logging a User Out
IPSec
- IPSec
- Introduction
- Configuring IPSec
- Configuring IPSec Dynamic SAs
- Creating IPSec Dynamic SAs on J-Series Routers or Routers with AS PICs
- Using Digital Certificates to Create Dynamic IPSec SAs
SNMP
- SNMP
- Introduction
- Configuring SNMP
- Setting Router Information for the MIB-II System Group
- Setting Up SNMP Traps
- Controlling SNMP Access to the Router
- Using a Firewall Filter to Protect SNMP Access
- Controlling Access to Router MIBs
- Extracting Software Inventory Information with SNMP
- Extracting Hardware Inventory Information with SNMP
- Collecting Router Operational Information with SNMP
- Logging SNMP Access to the Router
- Logging Enterprise-Specific Traps
- Using RMON Traps to Monitor the Routers Temperature
- Configuring SNMPv3
- Tracking Router Configuration Changes
- Setting Up SNMPv3 Traps
Logging
- Logging
- Introduction
- Turning On Logging
- Limiting the Messages Collected
- Including the Facility and Severity in Messages
- Changing the Size of a Logging File
- Clearing the Routers Logfiles
- Sending Log Messages to Your Screen
- Sending Logging Messages to a Log Server
- Saving Logging Messages to the Other Routing Engine
- Turning Off Logging
- Turning On Basic Tracing
- Monitoring Interface Traffic
NTP
- NTP
- Introduction
- Setting the Date and Time on the Router Manually
- Setting the Time Zone
- Synchronizing Time When the Router Boots
- Synchronizing Time Periodically
- Authenticating NTP
- Checking NTP Status
Router Interfaces
- Router Interfaces
- Introduction
- Viewing Interface Status
- Viewing Traffic Statistics on an Interface
- Setting an IP Address for the Router
- Setting the Routers Source Address
- Configuring an IPv4 Address on an Interface
- Configuring an IPv6 Address on an Interface
- Configuring an ISO Address on an Interface
- Creating an MPLS Protocol Family on a Logical Interface
- Configuring an Interface Description
- Choosing Primary and Preferred Interface Addresses
- Using the Management Interface
- Finding Out What IP Addresses Are Used on the Router
- Configuring Ethernet Interfaces
- Using VRRP on Ethernet Interfaces
- Connecting to an Ethernet Switch
- Configuring T1 Interfaces
- Performing a Loopback Test on a T1 Interface
- Setting Up a BERT Test on a T1 Interface
- Configuring Frame Relay on a T1 Interface
- Configuring a SONET Interface
- Using APS to Protect Against SONET Circuit Failures
- Configuring an ATM Interface
- Dealing with Nonconfigurable Interfaces
- Configuring Interfaces Before the PICs Are Installed
IP Routing
- IP Routing
- Introduction
- Viewing the Routes in the Routing Table
- Viewing Routes to a Particular Prefix
- Viewing Routes Learned from a Specific Protocol
- Displaying the Routes in the Forwarding Table
- Creating Static Routes
- Blackholing Routes
- Filtering Traffic Using Unicast Reverse-Path Forwarding
- Aggregating Routes
- Load-Balancing Traffic Flows
- Adding Martian Addresses
- Changing Route Preferences to Migrate to Another IGP
- Configuring Routing Protocols to Restart Without Losing Adjacencies
Routing Policy and Firewall Filters
- Routing Policy and Firewall Filters
- Introduction
- Creating a Simple Routing Policy
- Changing a Routes Routing Information
- Filtering Routes by IP Address
- Filtering Long Prefixes
- Filtering Unallocated Prefix Blocks
- Creating a Chain of Routing Policies
- Making Sure a Routing Policy Is Functioning Properly
- Creating a Simple Firewall Filter that Matches Packet Contents
- Creating a Firewall Filter that Negates a Match
- Reordering Firewall Terms
- Filtering Traffic Transiting the Router
- Using a Firewall Filter to Count Traffic on an Interface
- Logging the Traffic on an Interface
- Limiting Traffic on an Interface
- Protecting the Local Routing Engine
- Rate-Limiting Traffic Flow to the Routing Engine
- Using Counters to Determine Whether a Router Is Under Attack
RIP
- RIP
- Introduction
- Configuring RIP
- Having RIP Advertise Its Routes
- Configuring RIP for IPv6
- Enabling RIP Authentication
- Routing RIP Traffic over Faster Interfaces
- Sending Version 1 Update Messages
- Tracing RIP Protocol Traffic
IS-IS
- IS-IS
- Introduction
- Configuring IS-IS
- Viewing the IS-IS Link-State Database
- Viewing Routes Learned by IS-IS
- Configuring IS-IS for IPv6
- Configuring a Level 1Only Router
- Controlling DIS Election
- Enabling IS-IS Authentication
- Redistributing Static Routes into IS-IS
- Leaking IS-IS Level 2 Routes into Level 1
- Adjusting IS-IS Link Costs
- Improving IS-IS Convergence Times
- Moving IS-IS Traffic off a Router
- Disabling IS-IS on an Interface
- Tracing IS-IS Protocol Traffic
OSPF
- Introduction
- Configuring OSPF
- Viewing Routes Learned by OSPF
- Viewing the OSPF Link-State Database
- Configuring OSPF for IPv6
- Configuring a Multiarea OSPF Network
- Setting Up Stub Areas
- Creating a Not-So-Stubby Area
- Summarizing Routes in OSPF
- Enabling OSPF Authentication
- Redistributing Static Routes into OSPF
- Adjusting OSPF Link Costs
- Improving OSPF Convergence Times
- Moving OSPF Traffic off a Router
- Disabling OSPF on an Interface
- Tracing OSPF Protocol Traffic
BGP
- Introduction
- Configuring a BGP Session Between Routers in Two ASs
- Configuring BGP on Routers Within an AS
- Diagnosing TCP Session Problems
- Adjusting the Next-Hop Attribute
- Adjusting Local Preference Values
- Removing Private AS Numbers from the AS Path
- Prepending AS Numbers to the AS Path
- Filtering BGP Routes Based on AS Paths
- Restricting the Number of Routes Advertised to a BGP Peer
- Authenticating BGP Peers
- Setting Up Route Reflectors
- Mitigating Route Instabilities with Route Flap Damping
- Adding a BGP Community to Routes
- Load-Balancing BGP Traffic
- Tracing BGP Protocol Traffic
MPLS
- Introduction
- Configuring LSPs Using LDP as the Signaling Protocol
- Viewing Information and LDP-Signaled LSPs in the Routing Tables
- Verifying that an LDP-Signaled LSP Is Carrying Traffic
- Enabling LDP Authentication
- Tracing LDP Operations
- Setting Up RSVP-Signaled LSPs
- Viewing Information About RSVP-Signaled LSPs in the Routing Tables
- Verifying Packet Labels
- Verifying that the RSVP-Signaled LSP Is Carrying Traffic
- Configuring RSVP Authentication
- Protecting an LSPs Path
- Using Fast Reroute to Reduce Packet Loss Following a Link Failure
- Automatically Allocating Bandwidth
- Prioritizing LSPs
- Allowing IGP Traffic to Use an LSP
- Installing LSPs into the Unicast Routing Table
- Tracing RSVP Operations
VPNs
- Introduction
- Setting Up a Simple Layer 3 VPN
- Viewing the VPN Routing Tables
- Adding a VPN for a Second Customer
IP Multicast
- Introduction
- Configuring PIM-SM
- Manually Establishing a PIM-SM RP
- Using Auto-RP to Dynamically Map RPs
- Setting Up a PIM-SM Bootstrap Router
- Filtering PIM-SM Bootstrap Messages
- Configuring Multiple RPs in a PIM-SM Domain with Anycast RP
- Configuring Multiple RPs in a PIM-SM Domain Anycast PIM
- Limiting the Group Ranges an RP Services
- Viewing Multicast Routes
- Checking the Groups for Which a PIM-SM Router Maintains Join State
- Manually Configuring IGMP
- Using SSM
- Connecting PIM-SM Domains Using MSDP and MBGP
- Configuring PIM-DM
- Tracing PIM Packets
Junos Cookbook (Cookbooks (OReilly))
ISBN: 0596100140
EAN: 2147483647
EAN: 2147483647
Year: 2007
Pages: 290
Pages: 290
Authors: Aviva Garrett
