- Read Me First
- Configuring OSPF
- IPv6 Routing: OSPFv3
- IPv6 Routing: OSPFv3 Authentication Support with IPsec
- OSPFv2 Cryptographic Authentication
- OSPFv3 External Path Preference Option
- OSPFv3 Graceful Restart
- Graceful Shutdown Support for OSPFv3
- OSPF Stub Router Advertisement
- OSPF Update Packet-Pacing Configurable Timers
- OSPF Sham-Link Support for MPLS VPN
- OSPF Support for Multi-VRF on CE Routers
- OSPFv2 Multiarea Adjacency
- OSPFv2 Autoroute Exclude
- OSPFv3 Address Families
- OSPFv3 Authentication Trailer
- Autoroute Announce and Forwarding Adjacencies For OSPFv3
- OSPFv3 Autoroute Exclude
- OSPFv2 IP FRR Local Microloop Avoidance
- OSPFv2-OSPF Live-Live
- OSPF Forwarding Address Suppression in Translated Type-5 LSAs
- OSPF Inbound Filtering Using Route Maps with a Distribute List
- OSPFv3 Route Filtering Using Distribute-List
- OSPF Shortest Path First Throttling
- OSPF Support for Fast Hello Packets
- OSPF Incremental SPF
- OSPF Limit on Number of Redistributed Routes
- OSPFv3 Fast Convergence: LSA and SPF Throttling
- OSPFv3 Max-Metric Router LSA
- OSPF Link-State Advertisement Throttling
- OSPF Support for Unlimited Software VRFs per PE Router
- OSPF Area Transit Capability
- OSPF Per-Interface Link-Local Signaling
- OSPF Link-State Database Overload Protection
- OSPF MIB Support of RFC 1850 and Latest Extensions
- OSPF Enhanced Traffic Statistics
- TTL Security Support for OSPFv3 on IPv6
- Configuring OSPF TTL Security Check and OSPF Graceful Shutdown
- OSPF Sham-Link MIB Support
- OSPF SNMP ifIndex Value for Interface ID in Data Fields
- OSPFv2 Local RIB
- OSPF Support for Forwarding Adjacencies over MPLS TE Tunnels
- Enabling OSPFv2 on an Interface Basis
- OSPF Nonstop Routing
- OSPFv3 NSR
- OSPFv2 Loop-Free Alternate Fast Reroute
- OSPFv3 MIB
- Prefix Suppression Support for OSPFv3
- OSPFv3 VRF-Lite/PE-CE
- OSPFv3 ABR Type 3 LSA Filtering
- OSPFv3 Demand Circuit Ignore
- OSPF IPv4 Remote Loop-Free Alternate IP Fast Reroute
- OSPFv3 Multiarea Adjacency
- OSPF Limiting Adjacency Formations
- Finding Feature Information
- Prerequisites for OSPF Link-State Database Overload Protection
- Information About OSPF Link-State Database Overload Protection
- How to Configure OSPF Link-State Database Overload Protection
- Configuration Examples for OSPF Link-State Database Overload Protection
- Additional References
- Feature Information for OSPF Link-State Database Overload Protection
OSPF Link-State Database Overload Protection
The OSPF Link-State Database Overload Protection feature allows you to limit the number of nonself-generated link-state advertisements (LSAs) for a given Open Shortest Path First (OSPF) process. Excessive LSAs generated by other routers in the OSPF domain can substantially drain the CPU and memory resources of the router.
- Finding Feature Information
- Prerequisites for OSPF Link-State Database Overload Protection
- Information About OSPF Link-State Database Overload Protection
- How to Configure OSPF Link-State Database Overload Protection
- Configuration Examples for OSPF Link-State Database Overload Protection
- Additional References
- Feature Information for OSPF Link-State Database Overload Protection
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest caveats and feature information, see Bug Search Tool and the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the feature information table.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for OSPF Link-State Database Overload Protection
It is presumed that you have OSPF running on your network.
Information About OSPF Link-State Database Overload Protection
- Benefits of Using OSPF Link-State Database Overload Protection
- How OSPF Link-State Database Overload Protection Works
Benefits of Using OSPF Link-State Database Overload Protection
The OSPF Link-State Database Overload Protection feature provides a mechanism at the OSPF level to limit the number of nonself-generated LSAs for a given OSPF process. When other routers in the network have been misconfigured, they may generate a high volume of LSAs, for instance, to redistribute large numbers of prefixes. This protection mechanism prevents routers from receiving a large number of LSAs and therefore experiencing CPU and memory shortages.
How OSPF Link-State Database Overload Protection Works
When the OSPF Link-State Database Overload Protection feature is enabled, the router keeps a count of the number of received (nonself-generated) LSAs that it has received. When the configured threshold number of LSAs is reached, an error message is logged. When the configured maximum number of LSAs is exceeded, the router will send a notification. If the count of received LSAs is still higher than the configured maximum after one minute, the OSPF process takes down all adjacencies and clears the OSPF database. In this ignore state, all OSPF packets received on any interface that belongs to this OSPF process are ignored and no OSPF packets are generated on any of these interfaces. The OSPF process remains in the ignore state for the time configured by the ignore-time keyword of the max-lsa command. Each time the OSPF process gets into an ignore state a counter is incremented. If this counter exceeds the number of minutes configured by the ignore-count keyword, the OSPF process stays permanently in the same ignore state and manual intervention is required to get the OSPF process out of the ignore state. The ignore state counter is reset to 0 when the OSPF process remains in the normal state of operation for the amount of time that was specified by the reset-time keyword.
If the warning-only keyword of the max-lsa command has been configured, the OSPF process will send only a warning that the LSA maximum has been exceeded.
How to Configure OSPF Link-State Database Overload Protection
Limiting the Number of Self-Generating LSAs for an OSPF Process
1.
enable
2.
configure
terminal
3.
router
ospf
process-id
4.
router-id
ip-address
5.
log
-adjacency-changes [detail]
6.
max-lsa
maximum-number
[threshold-percentage] [warning-only] [ignore-time
minutes] [ignore-count
count-number] [reset-time
minutes]
7.
network
ip-address
wildcard-mask
area
area-id
8.
end
9.
show
ip
ospf
[process-id
area-id]
database[database-summary]
DETAILED STEPS
Example
The show ip ospf command is entered with the database-summary keyword to verify the actual number of nonself-generated LSAs on a router. This command can be used at any time to display lists of information related to the OSPF database for a specific router.
Router# show ip ospf 2000 database database-summary
OSPF Router with ID (192.168.1.3) (Process ID 2000)
Area 0 database summary
LSA Type Count Delete Maxage
Router 5 0 0
Network 2 0 0
Summary Net 8 2 2
Summary ASBR 0 0 0
Type-7 Ext 0 0 0
Prefixes redistributed in Type-7 0
Opaque Link 0 0 0
Opaque Area 0 0 0
Subtotal 15 2 2
Process 2000 database summary
LSA Type Count Delete Maxage
Router 5 0 0
Network 2 0 0
Summary Net 8 2 2
Summary ASBR 0 0 0
Type-7 Ext 0 0 0
Opaque Link 0 0 0
Opaque Area 0 0 0
Type-5 Ext 4 0 0
Prefixes redistributed in Type-5 0
Opaque AS 0 0 0
Non-self 16
Total 19 2 2
Configuration Examples for OSPF Link-State Database Overload Protection
Setting a Limit for LSA Generation Example
In the following example, the router is configured to not accept any more nonself-generated LSAs once a maximum of 14,000 has been exceeded:
Router(config)# router ospf 1 Router(config-router)# router-id 192.168.0.1 Router(config-router)# log-adjacency-changes Router(config-router)# max-lsa 14000 Router(config-router)# area 33 nssa Router(config-router)# network 192.168.0.1 0.0.0.0 area 1 Router(config-router)# network 192.168.5.1 0.0.0.0 area 1 Router(config-router)# network 192.168.2.1 0.0.0.0 area 0
In the following example, the show ip ospf command has been entered to confirm the configuration:
Router# show ip ospf 1 Routing Process "ospf 1" with ID 192.168.0.1 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Maximum number of non self-generated LSA allowed 14000 Threshold for warning message 75% Ignore-time 5 minutes, reset-time 10 minutes Ignore-count allowed 5, current ignore-count 0 It is an area border and autonomous system boundary router
In the following example, the following output appears when the show ip ospf command has been entered during the time when the router is in the ignore state:
Router# show ip ospf 1 Routing Process "ospf 1" with ID 192.168.0.1 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Maximum number of non self-generated LSA allowed 14000 Threshold for warning message 75% Ignore-time 5 minutes, reset-time 10 minutes Ignore-count allowed 5, current ignore-count 1 Ignoring all neighbors due to max-lsa limit, time remaining: 00:04:52 It is an area border and autonomous system boundary router
The following output appears when the show ip ospf command has been entered after the router left the ignore state:
Router# show ip ospf 1 Routing Process "ospf 1" with ID 192.168.0.1 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Maximum number of non self-generated LSA allowed 14000 Threshold for warning message 75% Ignore-time 5 minutes, reset-time 10 minutes Ignore-count allowed 5, current ignore-count 1 - time remaining: 00:09:51 It is an area border and autonomous system boundary router
The following output appears when the show ip ospf command has been entered for a router that is permanently in the ignore state:
Router# show ip ospf 1 Routing Process "ospf 1" with ID 192.168.0.1 Supports only single TOS(TOS0) routes Supports opaque LSA Supports Link-local Signaling (LLS) Supports area transit capability Maximum number of non self-generated LSA allowed 14000 Threshold for warning message 75% Ignore-time 5 minutes, reset-time 10 minutes Ignore-count allowed 5, current ignore-count 6 Permanently ignoring all neighbors due to max-lsa limit It is an area border and autonomous system boundary router
Additional References
The following sections provide references related to the OSPF Link-State Database Overload Protection feature.
Related Documents
|
Related Topic |
Document Title |
|---|---|
|
Configuring OSPF |
" Configuring OSPF" |
|
OSPF commands |
Cisco IOS IP Routing: OSPF Command Reference |
|
Cisco IOS master command list, all releases |
Standards
|
Standard |
Title |
|---|---|
|
None |
-- |
MIBs
|
MIB |
MIBs Link |
|---|---|
|
No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
|
RFC |
Title |
|---|---|
|
None |
-- |
Technical Assistance
|
Description |
Link |
|---|---|
|
The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |
Feature Information for OSPF Link-State Database Overload Protection
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
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