© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-1 Implementing an EIGRP-Based Solution Configuring and Verifying EIGRP for the Enterprise WAN Architecture

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-2 Frame Relay Overview  Frame Relay network –NBMA = nonbroadcast multiaccess network –Pseudo-broadcasting  Requires mapping from Layer 3 to Layer 2 (IP-to-DLCI) –Static mapping –Dynamic mapping  Neighbor loss detected only after the hold time expires or the interface goes down  Different topologies –Full mesh –Partial mesh –Hub and spoke

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-3 EIGRP with Dynamic Mapping  A single IP subnet is used  Inverse ARP is enabled by default  Split horizon is disabled on the physical interface by default interface Serial0/0 encapsulation frame-relay ip address ! router eigrp 110 network network R1#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-4 EIGRP with Dynamic Mapping (Cont.) R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :07: Se0/ :09: R3#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :11: Se0/ :02:

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-5 EIGRP with Static Mapping  A single IP subnet is used  Split horizon is disabled on the physical interface by default  Inverse ARP is not used R1(config)# interface Serial0/0 encapsulation frame-relay ip address frame-relay map ip frame-relay map ip broadcast frame-relay map ip broadcast ! router eigrp 110 network network

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-6 EIGRP with Static Mapping (Cont.) R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :06: Se0/ :08: R3#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :10: Se0/ :03:

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-7 Frame Relay Multipoint Subinterfaces  Several multipoint subinterfaces can be created: –Logical interfaces emulating the multiaccess network –Like NBMA physical interfaces for routing purposes  IP address space may be saved, since a single subnet is used.  Subinterfaces are applicable to partial-mesh and full-mesh topologies.  Neighbor loss is detected only after the hold time expires or the subinterface goes down.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-8 EIGRP over Multipoint Subinterfaces  A single IP subnet is used.  Mapping is applied to the subinterface.  Split horizon must be disabled in partial-mesh topologies. interface Serial0/0 no ip address encapsulation frame-relay no frame-relay inverse-arp eigrp 110 ! interface Serial0/0.1 multipoint ip address no ip split-horizon eigrp 110 frame-relay map ip frame-relay map ip broadcast frame-relay map ip broadcast ! router eigrp 110 network network R1#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-9 EIGRP over Multipoint Subinterfaces (Cont.) R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :06: Se0/ :08: R3#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :10: Se0/ :03:

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-10 EIGRP Unicast Neighbor Setting a neighbor with the command to enable a unicast neighbor relationship interface FastEthernet0/0 ip address ! interface Serial0/0.1 multipoint ip address frame-relay map ip broadcast frame-relay map ip broadcast ! router eigrp 110 network network neighbor R1#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-11 EIGRP Unicast Neighbor (cont.) interface FastEthernet0/0 ip address ! interface Serial0/0.1 multipoint ip address frame-relay map ip broadcast ! router eigrp 110 network network neighbor R2#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-12 Verifying EIGRP Unicast Neighbors R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/0/ :07: R2#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/0/ :17:

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-13 Frame Relay Point-to-Point Subinterfaces  Several point-to-point subinterfaces can be created: –Logical interfaces emulating a leased-line network –Like physical point-to-point interfaces for routing purposes  Each point-to-point subinterface requires its own subnet.  Applicable to hub-and-spoke topologies.  Neighbor loss is detected after the hold time expires, the subinterface goes down, or the DLCI is lost.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-14 EIGRP over Point-to-Point Subinterfaces interface Serial0/0 no ip address encapsulation frame-relay ! interface Serial0/0.2 point-to-point ip address frame-relay interface-dlci 102 ! interface Serial0/0.3 point-to-point ip address frame-relay interface-dlci 103 ! router eigrp 110 network network network R1# interface Serial0/0 no ip address encapsulation frame-relay ! interface Serial0/0.1 point-to-point ip address frame-relay interface-dlci 103 ! router eigrp 110 network network R3#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-15 EIGRP over Point-to-Point Subinterfaces (Cont.) R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :08: Se0/ :10: R3#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Se0/ :13:

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-16 EIGRP Load Balancing  Routes with a metric equal to the minimum metric are installed in the routing table - equal-metric load balancing  Up to 16 entries can be in the routing table for the same destination (default is 4) –Maximum number is configurable –To disable load balancing, set the value to one  To control the maximum number of parallel routes that an IP routing protocol can support router eigrp 110 maximum–paths 2 R1(config)#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-17 EIGRP Load Balancing (Cont.) router eigrp 110 network network network network network maximum–paths 3 R1# R1#show ip route eigrp /16 is variably subnetted, 2 subnets, 2 masks D /24 [90/ ] via , 00:07:01, Serial1/1 [90/ ] via , 00:07:01, Serial1/2 [90/ ] via , 00:07:01, Serial1/3

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-18 EIGRP Unequal-Cost Load Balancing  The router can balance traffic across multiple routes that have different metrics to a destination –Successor is always used –Feasible successors are used if the cost is less than (minimum cost * variance) –Variance is only a multiplier, not a max-path parameter –The maximum number of paths is limited by the maximum– paths command  Variance opens the gate for unequal-cost load balancing  To control load balancing in an internetwork based on EIGRP router eigrp 110 variance 2 R1(config)#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-19 router eigrp 110 variance 2 EIGRP Unequal-Cost Load Balancing (Cont.) R1# R1 EIGRP Topology for NetworkNeighborFDAD R23010 R32010 R44525 R55010 R1#show ip route eigrp /16 is variably subnetted, 2 subnets, 2 masks D /24 [90/ ] via , 00:07:01, Serial1/2 [90/ ] via , 00:07:01, Serial1/1 - AD(R4)>FD(R3) - Variance: 50(FD)>2*20(FD,Successor)

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-20 EIGRP Bandwidth Utilization over WAN  Up to 50% of bandwidth is utilized by default and can be changed  Point-to-point interfaces –Treat bandwidth as T1 by default –Configure bandwidth manually  Multipoint interfaces –Bandwidth on the physical interface divided by the number of neighbors on that interface  To configure the percentage of bandwidth that may be used by EIGRP on an interface bandwidth 256 ip bandwidth-percent eigrp R1(config-if)#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-21 Bandwidth Utilization Issues  Each PVC can have a different CIR, creating an EIGRP packet- pacing problem.  Multipoint interfaces: –Convert to point-to-point configuration OR –Manually configure bandwidth by multiplying the lowest CIR by the number of PVCs. PVCBandwidth (kb/s)

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-22 EIGRP Hub-and-Spoke WAN Utilization  Configure each VC as point-to-point—do not change number of VCs to preserve the configuration  Set bandwidth to 1/10 of link capacity  Increase EIGRP utilization to 50% of actual VC capacity interface serial0 bandwidth 256 interface serial0.1 point-to-point ip bandwidth-percent eigrp interface serial0.10 point-to-point ip bandwidth-percent eigrp R1# interface serial0 bandwidth 25 ip bandwidth-percent eigrp R5#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-23 EIGRP Multipoint WAN Utilization  Solution 1: create on multipoint interfaces  (Lowest CIR * number of VCs) = (56 kb/s * 4) = 224 kb/s interface serial0 bandwidth 224 R1(config)#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-24 EIGRP Hybrid Multipoint WAN Utilization (Cont.)  Solution 2: create separate multipoint interfaces –Configure the lowest CIR VC as point-to-point and set bandwidth = CIR. –Configure higher CIR VCs as multipoint, combine CIRs, and configure the sum of bandwidth to the subinterface. interface serial0.1 multipoint bandwidth 768 ! interface serial0.2 point-to-point bandwidth 56 R1#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-25 AToM Overview  Service providers offer Layer 2 transport services to connect customer equipment (CE) –Ethernet, Ethernet VLAN –ATM –PPP, HLDC, and so on  Any Transport Over MPLS –Enables the sending of Layer 2 frames across the MPLS backbone –Unifies Layer 2 and Layer 3 over a common MPLS infrastructure –Virtual circuits represent Layer 2 links –Labels identify virtual circuits

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-26 Layer 2 and Layer 3 MPLS VPN Solutions  Layer 2 MPLS VPN backbone solution  Layer 3 MPLS VPN backbone solution

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-27 Layer 3 MPLS VPN Overview  Service provider is connecting multiple customers over a common MPLS backbone using MPLS VPNs  Customer Edge (CE) devices connect into the service provider MPLS VPN network

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-28 Customer MPLS Perspective  CE routers run EIGRP and exchange routing updates with the PE router –The PE router appears as another router in the customer’s network –The service provider’s P-routers are hidden from the customer –CE-routers are unaware of MPLS VPN  EIGRP parameters must be agreed upon with service provider

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-29 Ethernet Port-to-Port Connectivity  Customer routers R1 and R2 exchange Ethernet frames  Frame propagation occurs across the MPLS transport network –Ethernet frames: from R1 to PE1 and from PE2 to router R2 –MPLS packet: Between PE1 and PE2  EoMPLS service does participate in Spanning Tree Protocol nor learns MAC addresses

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-30 Ethernet VLAN Connectivity  Customer routers R1 and R2 exchange Ethernet frames via VLAN subinterfaces  Frame propagation occurs across the MPLS transport network –Ethernet frames: from R1 to PE1 and from PE2 to router R2 –MPLS packet: Between PE1 and PE2  EoMPLS service does participate in Spanning Tree Protocol nor learns MAC addresses

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-31 EIGRP over EoMPLS interface FastEthernet0/0 ip address ! router eigrp 110 network network interface FastEthernet0/0 ip address ! router eigrp 110 network network R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Fe0/ :07: R2#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Fe0/ :17: R2#R2# R1#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-32 EIGRP over Layer 3 MPLS VPN interface FastEthernet0/0 ip address ! router eigrp 110 network network interface FastEthernet0/0 ip address ! router eigrp 110 network network R1#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Fe0/ :07: R2#show ip eigrp neighbors IP-EIGRP neighbors for process 110 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num Fe0/ :17: R1# R2#R2#

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-33 Summary  When EIGRP is deployed over a Frame Relay physical interface, neighbor loss is detected after the hold time expires or all DLCIs are down.  EIGRP routing behavior over Frame Relay multipoint interfaces is equivalent to NBMA physical interfaces.  When EIGRP is deployed over a Frame Relay point-to-point interface, neighbor loss is detected after the hold time expires or the interface DLCI goes down  EIGRP performs equal-cost load balancing by default for up to four paths (up to six paths can be supported).

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-34 Summary (Cont.)  To support unequal-cost load balancing, a multiplier parameter (variance) should be configured.  EIGRP uses up to 50% of the bandwidth of an interface by default. This may not be the best option for all WAN links, due to the inherent differences in the operational characteristics of WANs.  CE-routers connected to a service provider’s EoMPLS (Layer 2 MPLS VPN) treat the connection as a separate subnet. Therefore, EIGRP operates normally without changes in the basic configuration.  A customer connected to a Layer 3 MPLS VPN must agree with its service provider on EIGRP parameters (AS number, authentication, and so on) in order to deploy routing.

© 2009 Cisco Systems, Inc. All rights reserved. ROUTE v1.0—2-35