Page 3 - C O N T E N T S; MPLS LDP Session Protection
C O N T E N T S MPLS Label Distribution Protocol (LDP) 1 Finding Feature Information 1 Prerequisites for MPLS LDP 1 Information About MPLS LDP 1 Introduction to MPLS LDP 2 MPLS LDP Functional Overview 2 LDP and TDP Support 2 Introduction to LDP Sessions 3 Directly Connected MPLS LDP Sessions 3 Nondi...
Page 5 - MPLS LDP Graceful Restart
MPLS LDP Graceful Restart 65 Finding Feature Information 65 Restrictions 65 Information About MPLS LDP Graceful Restart 66 How MPLS LDP Graceful Restart Works 66 How a Route Processor Advertises That It Supports MPLS LDP Graceful Restart 67 What Happens If a Route Processor Does Not Have LDP Gracefu...
Page 8 - Train and Release; TDP is enabled by default.
Introduction to MPLS LDP MPLS LDP provides the means for LSRs to request, distribute, and release label prefix binding informationto peer routers in a network. LDP enables LSRs to discover potential peers and to establish LDP sessionswith those peers for the purpose of exchanging label binding infor...
Page 9 - LDP is enabled by default.; Directly Connected MPLS LDP Sessions, page 3; Directly Connected MPLS LDP Sessions; For information about creating LDP sessions, see the
Train and Release LDP/TDP Support 12.2S, SB, and SR Trains • LDP is enabled by default. • Cisco IOS Release 12.2(25)S and earlier releases: TDP issupported for LDP features. • Cisco IOS Releases 12.2(27)SBA, 12.2(27)SRA,12.2(27)SRB and later releases: TDP is not supported forLDP features. 12.T/Mainl...
Page 10 - Establishing Nondirectly Connected
Nondirectly Connected MPLS LDP Sessions If the LSR is more than one hop from its neighbor, it is nondirectly connected to its neighbor. For thesenondirectly connected neighbors, the LSR sends out a targeted Hello message as a UDP packet, but as aunicast message specifically addressed to that LSR. Th...
Page 11 - Enabling Directly Connected LDP Sessions, page 6
• Platform-wide--An LDP platform supports a single platform-wide label space for use by interfaces thatcan share the same labels. For Cisco platforms, all interface types, except LC-ATM, use the platform-wide label space. LDP uses a 6-byte quantity called an LDP Identifier (or LDP ID) to name label ...
Page 12 - SUMMARY STEPS; Command or Action; Enables privileged EXEC mode.; Enters global configuration mode.
• Establishing Nondirectly Connected MPLS LDP Sessions, page 8 • Saving Configurations MPLS Tag Switching Commands, page 11 • Specifying the LDP Router ID, page 12 • Preserving QoS Settings with MPLS LDP Explicit Null, page 14 • Protecting Data Between LDP Peers with MD5 Authentication, page 18 Enab...
Page 13 - Configures the use of LDP on all interfaces. LDP is the default.
Command or Action Purpose Step 4 mpls label protocol {ldp | tdp | both} Example: Router(config)# mpls label protocol ldp Configures the use of LDP on all interfaces. LDP is the default. • If you set all interfaces globally to LDP, you can overridespecific interfaces with either the tdp or both keywo...
Page 14 - Displays the status of LDP sessions.; Examples; Configuring Directly Connected
Command or Action Purpose Step 11 show mpls ldp neighbor [[vrf vpn-name] [address |interface] [detail] | [all]] Example: Router# show mpls ldp neighbor Displays the status of LDP sessions. Examples The following show mpls interfaces command verifies that interfaces Ethernet 1/0 and 1/1 have beenconf...
Page 15 - interface tunnelnumber; DETAILED STEPS
SUMMARY STEPS 1. enable 2. configure terminal 3. mpls ip 4. mpls label protocol {ldp | tdp | both} 5. interface tunnelnumber 6. tunnel destination ip-address 7. mpls ip 8. exit 9. exit 10. show mpls ldp discovery [all | vrf vpn-name] [detail DETAILED STEPS Command or Action Purpose Step 1 enable Exa...
Page 16 - mpls ip; Exits global configuration mode and enters privileged EXEC mode.; Example
Command or Action Purpose Step 5 interface tunnelnumber Example: Router(config)# interface tunnel1 Configures a tunnel interface and enters interface configurationmode. Step 6 tunnel destination ip-address Example: Router(config-if)# tunnel destination 172.16.1.1 Assigns an IP address to the tunnel ...
Page 18 - If the loopback interface has been explicitly shut down.
ip unnumbered Loopback0mpls ipmpls label protocol ldp Specifying the LDP Router ID The mpls ldp router-id command allows you to establish the IP address of an interface as the LDP routerID. The following steps describe the normal process for determining the LDP router ID: 1 The router considers all ...
Page 20 - show; Displays the LDP identifier for the local router.
Command or Action Purpose Step 6 exit Example: Router(config)# exit Exits global configuration mode and enters privileged EXEC mode. Step 7 show mpls ldp discovery [all | detail |vrf vpn-name] Example: Router# show mpls ldp discovery Displays the LDP identifier for the local router. Example The foll...
Page 26 - Specifies authentication between two LDP peers.
Command or Action Purpose Step 5 mpls ldp neighbor [vrf vpn-name] ip-address[password[0-7] password-string] Example: Router(config)# mpls ldp neighbor 172.27.0.15 password onethirty9 Specifies authentication between two LDP peers. Step 6 exit Example: Router(config)# exit Exits global configuration ...
Page 27 - MPLS LDP Configuration Examples; This example configures the following:
Peer LDP Ident: 10.0.0.21:0; Local LDP Ident 10.0.0.22:0 TCP connection: 10.0.0.21.646 - 10.0.0.22.14709; MD5 on State: Oper; Msgs sent/rcvd: 1020/1019; Downstream; Last TIB rev sent 2034 Up time: 00:00:39; UID: 3; Peer Id 1; LDP discovery sources: FastEthernet1/1; Src IP addr: 172.16.1.1 holdtime: ...
Page 28 - Router 1 Configuration
Note The configuration examples below show only the commands related to configuring LDP for Router 1,Router 2, and Router 3 in the sample network shown in the figure above. Router 1 Configuration ip cef distributed !Assumes R1 supports distributed CEF interface Loopback0 !Loopback interface for LDP ...
Page 29 - The configuration example shows the following:
!Use LDP (configured i/f default)interface POS3/0/1 ip address 192.168.0.44 255.0.0.0 mpls ip !Enable hop-by-hop MPLS forwarding mpls label protocol tdp !Use TDP for this interface The configuration of Router 2 also uses the mpls label protocol ldpcommand in interface configurationmode. To specify L...
Page 31 - MPLS LDP Autoconfiguration
Additional References Related Documents Related Topic Document Title Configures LDP on every interface associated witha specified IGP instance. MPLS LDP Autoconfiguration Ensures that LDP is fully established before theIGP path is used for switching. MPLS LDP-IGP Synchronization Allows ACLs to contr...
Page 33 - Feature Name
Table 2 Feature Information for MPLS Label Distribution Protocol Overview Feature Name Releases Feature Information MPLS Label DistributionProtocol 12.0(10)ST 12.0(14)ST 12.1(2)T12.1(8a)E 12.2(2)T 12.2(4)T12.2(8)T 12.0(21)ST 12.0(22)S12.0(23)S 12.2(13)T 12.4(3)12.4(5) This feature was introduced inC...
Page 34 - LDP and TDP
Feature Name Releases Feature Information In Cisco IOS Release 12.2(4)T,support was added for CiscoMGX 8850 and MGX 8950switches equipped with a CiscoMGX RPM-PR card, and the VPIrange in the show mpls atm-ldpbindings and show mpls ipbinding commands was changedto 4095. In Cisco IOS Release 12.2(8)T,...
Page 35 - Saving Configurations MPLS
Feature Name Releases Feature Information rather than the tag-switchingform. Previously, commandswere saved by using the tag-switching form of the command,for backward compatibility. Seethe Saving Configurations MPLS Tag Switching Commands, page11 for more information. In Cisco IOS Release 12.4(5), ...
Page 37 - Finding Feature Information; This feature is not supported under the following circumstances:; Information About MPLS LDP Session Protection
MPLS LDP Session Protection The MPLS LDP Session Protection feature provides faster label distribution protocol convergence when alink recovers following an outage. MPLS LDP Session Protection protects a label distribution protocol(LDP) session between directly connected neighbors or an LDP session ...
Page 38 - MPLS LDP Session Protection Customizations, page 32; Enabling MPLS LDP Session Protection on Specified Peer Routers
• If the LSR is one hop from its neighbor, it is directly connected to its neighbor. The LSR sends outLDP Hello messages as User Datagram Protocol (UDP) packets to all the routers on the subnet. Thehello message is called an LDP Link Hello. A neighboring LSR responds to the hello message and thetwo ...
Page 39 - How to Configure MPLS LDP Session Protection; Enabling MPLS LDP Session Protection, page 33
How to Configure MPLS LDP Session Protection • Enabling MPLS LDP Session Protection, page 33 • Verifying MPLS LDP Session Protection, page 35 • Troubleshooting Tips, page 36 Enabling MPLS LDP Session Protection You use the mpls ldp session protection command to enable MPLS LDP Session Protection. Th...
Page 41 - Exits from interface configuration mode.; show mpls ldp discovery
Command or Action Purpose Step 9 exit Example: Router(config-if)# exit Exits from interface configuration mode. Step 10 mpls ldp session protection [vrf vpn-name] [for acl][duration seconds] Example: Router(config)# mpls ldp session protection Enables MPLS LDP Session Protection. Verifying MPLS LDP ...
Page 42 - Configuration Examples for MPLS LDP Session Protection
Up time: 21:09:56LDP discovery sources: Targeted Hello 10.0.0.5 -> 10.0.0.3, activeAddresses bound to peer LDP Ident: 10.3.104.3 10.0.0.2 10.0.0.3 Step 3 show mpls ldp neighbor detailIssue this command to check that the MPLS LDP Session Protection state is Ready or Protecting. If the second lastl...
Page 45 - LDP Specification
interface Ethernet1/4 ip address 10.0.0.2 255.0.0.0 no ip directed-broadcast full-duplex mpls label protocol ldp tag-switching ip!router ospf 100 log-adjacency-changes redistribute connected network 10.0.0.5 0.0.0.0 area 100 network 10.0.0.0 0.255.255.255 area 100 network 10.0.0.0 0.255.255.255 area...
Page 46 - Command Reference; or to the Cisco IOS Master Commands List.; debug mpls ldp session protection
Technical Assistance Description Link The Cisco Support website provides extensiveonline resources, including documentation and toolsfor troubleshooting and resolving technical issueswith Cisco products and technologies. Access tomost tools on the Cisco Support website requires aCisco.com user ID an...
Page 47 - MPLS LDP Inbound Label Binding Filtering; Finding Feature Information, page 41
MPLS LDP Inbound Label Binding Filtering Multiprotocol Label Switching (MPLS) Label Distribution Protocol (LDP) supports inbound label bindingfiltering. You can use the MPLS LDP Inbound Label Binding Filtering feature to configure access controllists (ACLs) for controlling the label bindings a label...
Page 48 - How to Configure MPLS LDP Inbound Label Binding Filtering; Configuring MPLS LDP Inbound Label Binding Filtering, page 42
How to Configure MPLS LDP Inbound Label Binding Filtering • Configuring MPLS LDP Inbound Label Binding Filtering, page 42 • Verifying that MPLS LDP Inbound Label Bindings are Filtered, page 44 Configuring MPLS LDP Inbound Label Binding Filtering Perform this task to configure a router for inbound la...
Page 49 - Defines a standard IP access list with a number.; exit
Command or Action Purpose Step 3 ip access-list standard access-list-number Example: Example: Router(config)# ip access-list standard 1 Defines a standard IP access list with a number. Step 4 permit {source [source-wildcard] | any} [log] Example: Example: Router(config-std-nacl)# permit 10.0.0.0 Spe...
Page 51 - Configuration Examples for MPLS LDP Inbound Label Binding
access-list-number | access-list-name] Note It is important that you enter this command to see how the access list is defined; otherwise, you cannot verifyinbound label binding filtering. The following command output shows the contents of IP access list 1: Example: Router# show ip access 1Standard I...
Page 52 - MPLS Label Distribution Protocol
In the following example, the show mpls ldp bindings neighborcommand displays label bindings thatwere learned from 10.110.0.10. This example verifies that the LIB does not contain label bindings forprefixes that have been excluded. Router# show mpls ldp bindings neighbor 10.110.0.10tib entry: 10.2.0...
Page 53 - Feature Information for MPLS LDP Inbound Label Binding
Technical Assistance Description Link The Cisco Technical Support website containsthousands of pages of searchable technical content,including links to products, technologies, solutions,technical tips, and tools. Registered Cisco.comusers can log in from this page to access even morecontent. http://...
Page 54 - Glossary
Table 3 Feature Information for MPLS LDP Inbound Label Binding Filtering Feature Feature Name Releases Feature Information MPLS LDP Inbound LabelBinding Filtering Feature 12.0(26)S 12.2(25)S 12.3(14)T 12.2(18)SXE You can use the MPLS LDPInbound Label Binding Filteringfeature to configure accesscontr...
Page 58 - Information About MPLS LDP Autoconfiguration; MPLS LDP Autoconfiguration on OSPF and IS-IS Interfaces, page 52; How to Configure MPLS LDP Autoconfiguration; Verifying MPLS LDP Autoconfiguration with OSPF, page 55; Configuring MPLS LDP Autoconfiguration with OSPF Interfaces
Information About MPLS LDP Autoconfiguration To enable LDP, you should configure it globally and on each interface where it is needed. ConfiguringLDP on many interfaces can be time-consuming. The following section provides information aboutautoconfiguration feature on OSPF and IS-IS interfaces: • MP...
Page 60 - Enables OSPF routing and enters router configuration mode.
Command or Action Purpose Step 8 router ospf process-id Example: Router(config)# router ospf 1 Enables OSPF routing and enters router configuration mode. Step 9 network ip-address wildcard-mask area area-id Example: Router(config-router)# network 10.0.0.0 0.0.255.255 area 3 Specifies the interface o...
Page 62 - Enables privileged EXEC mode. Enter your password if prompted.; If LDP is enabled by the mpls ip command, the output displays:
Enables privileged EXEC mode. Enter your password if prompted. Step 2 show mpls interfaces [type number | vrf vpn-name][all] [detail] [internal]The show mpls interfaces command displays the method used to enable LDP on an interface: • If LDP is enabled by the mpls ldp autoconfigcommand, the output d...
Page 64 - Assigns an IP address to the interface.
Command or Action Purpose Step 3 interface type number Example: Router(config)# interface POS 0/2 Specifies the interface to configure and enters interfaceconfiguration mode. Step 4 ip address prefix mask Example: Router(config-if)# ip address 10.50.72.4 255.0.0.0 Assigns an IP address to the interf...
Page 66 - interface type number; no mpls ldp igp autoconfig; Disables LDP for that interface.; end; enable
Command or Action Purpose Step 3 interface type number Example: Router(config)# interface POS 3/0 Specifies the interface to configure and enters interfaceconfiguration mode. Step 4 no mpls ldp igp autoconfig Example: Router(config-if)# no mpls ldp igp autoconfig Disables LDP for that interface. Ste...
Page 67 - Troubleshooting Tips, page 61; Configuration Examples for MPLS LDP Autoconfiguration; MPLS LDP Autoconfiguration with OSPF Example, page 61
• IS-IS is up. • LDP is enabled. If the MPLS LDP Autoconfiguration feature is not enabled on an interface, the output looks like the following: Example: Interface: Ethernet0; ISIS tag null enabled ISIS is UP on interface AUTOCONFIG Information : LDP enabled: NO SYNC Information : Required: NO • Trou...
Page 69 - Feature Information for MPLS LDP Autoconfiguration
MIBs MIB MIBs Link MPLS LDP MIB To locate and download MIBs for selectedplatforms, Cisco IOS releases, and feature sets, useCisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs RFCs RFC Title RFC 3036 LDP Specification RFC 3037 LDP Applicability Technical Assistance Description...
Page 72 - MPLS LDP GR is supported in strict helper mode.; Information About MPLS LDP Graceful Restart; How MPLS LDP Graceful Restart Works, page 66
• MPLS LDP GR is supported in strict helper mode. • Tag Distribution Protocol (TDP) sessions are not supported. Only LDP sessions are supported. • MPLS LDP GR cannot be configured on label-controlled ATM (LC-ATM) interfaces. • MPLS LDP SSO/NSF is supported in IOS Release 12.2(25)S. It is not support...
Page 73 - Restart; The FT session TLV includes the following information:; Configuring MPLS LDP Graceful Restart, page 67; Configuring MPLS LDP Graceful Restart
• mpls ldp graceful-restart timers neighbor-liveness • mpls ldp graceful-restart timers max-recovery How a Route Processor Advertises That It Supports MPLS LDP Graceful Restart A route processor that is configured to perform MPLS LDP GR includes the Fault Tolerant (FT) TypeLength Value (TLV) in the ...
Page 75 - Configures the use of LDP for an interface. You must use LDP.; show mpls ldp graceful-restart; Configuration Example for MPLS LDP Graceful Restart
Command or Action Purpose Step 6 mpls ip Example: Router(config-if)# mpls ip Configures MPLS hop-by-hop forwarding for an interface. Step 7 mpls label protocol {ldp| tdp| both} Example: Router(config-if)# mpls label protocol ldp Configures the use of LDP for an interface. You must use LDP. Note You ...
Page 76 - Router 1 configured with LDP GR:
Router 1 configured with LDP GR: boot system slot0:rsp-pv-mz hw-module slot 2 image slot0:rsp-pv-mz hw-module slot 3 image slot0:rsp-pv-mz !ip subnet-zeroip cefmpls label range 16 10000 static 10001 1048575mpls label protocol ldpmpls ldp logging neighbor-changesmpls ldp graceful-restartmpls traffic-...
Page 79 - Feature Information for MPLS LDP Graceful Restart
RFCs RFCs 2 Title RFC 3036 LDP Specification RFC 3478 Graceful Restart Mechanism for Label Distribution Technical Assistance Description Link The Cisco Technical Support & Documentationwebsite contains thousands of pages of searchabletechnical content, including links to products,technologies, s...
Page 80 - mpls ldp graceful-restart
Table 5 Feature Information for MPLS LDP Graceful Restart Feature Name Releases Feature Information MPLS LDP Graceful Restart 12.0(29)S 12.3(14)T12.2(33)SRA MPLS LDP Graceful Restartassists a neighboring router thathas MPLS LDP StatefulSwitchover/Nonstop Forwarding(SSO/NSF) Support and GracefulResta...
