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1、Configuring EIGRP,Configuring Advanced EIGRP Options,EIGRP Route Summarization: Automatic,Purpose: Smaller routing tables, smaller updates Automatic summarization: On major network boundaries, subnetworks are summarized to a single classful (major) network. Automatic summarization occurs by default.
2、,EIGRP Route Summarization: Manual,Manual summarization has the following characteristics: Summarization is configurable on a per-interface basis in any router within a network. When summarization is configured on an interface, the router immediately creates a route pointing to null0. Loop-preventio
3、n mechanism When the last specific route of the summary goes away, the summary is deleted. The minimum metric of the specific routes is used as the metric of the summary route.,no auto-summary,(config-router)#,Turns off automatic summarization for the EIGRP process,Configuring Route Summarization,ip
4、 summary-address eigrp as-number address mask admin-distance,(config-if)#,Creates a summary address that this interface will generate,Manually Summarizing EIGRP Routes,Router C Routing Table,RouterC#show ip routeGateway of last resort is not set172.16.0.0/16 is variably subnetted, 3 subnets, 2 masks
5、 D 172.16.0.0/16 is a summary, 00:00:04, Null0 D 172.16.1.0/24 90/156160 via 10.1.1.2, 00:00:04, FastEthernet0/0 D 172.16.2.0/24 90/20640000 via 10.2.2.2, 00:00:04, Serial0/0/1 C 192.168.4.0/24 is directly connected, Serial0/0/010.0.0.0/8 is variably subnetted, 3 subnets, 2 masks C 10.2.2.0/24 is di
6、rectly connected, Serial0/0/1 C 10.1.1.0/24 is directly connected, FastEthernet0/0 D 10.0.0.0/8 is a summary, 00:00:05, Null0 RouterC#,EIGRP Load Balancing,Routes with a metric equal to the minimum metric are installed in the routing table (equal-cost load balancing). There can be up to six entries
7、in the routing table for the same destination: The number of entries is configurable. The default is four. Set to 1 to disable load balancing.,EIGRP Unequal-Cost Load Balancing,variance multiplier,Allows the router to include routes with a metric smaller than the multiplier value times the minimum m
8、etric route to that destination,Router(config-router)#,Router E chooses router C to get to network Z, because it has lowest FD of 20. With a variance of 2, router E chooses router B to get to network Z (20 + 10 = 30) 20).,Variance Example,Configuring WAN Links,EIGRP supports different WAN links: Poi
9、nt-to-point links NBMA Multipoint links Point-to-point links EIGRP uses up to 50% of bandwidth by default; this bandwidth utilization can be changed.,Bandwidth Utilization over WAN Interfaces,Bandwidth utilization over point-to-point subinterfaces using Frame Relay: Treats bandwidth as T1 by default
10、 Should manually configure bandwidth as the CIR of the PVC Bandwidth utilization over multipoint Frame Relay, ATM, and ISDN PRI: EIGRP uses the bandwidth on the physical interface divided by the number of neighbors on that interface to calculate the bandwidth attributed per neighbor.,Bandwidth Utili
11、zation over WAN Interfaces (Cont.),Each PVC can have a different CIR, creating an EIGRP packet-pacing problem. Multipoint interfaces: Convert these to point-to-point configuration or manually configure bandwidth by multiplying the lowest CIR by the number of PVCs.,EIGRP WAN Configuration: Frame Rela
12、y Hub-and-Spoke Topology,Configure each virtual Circuit as point-to-point, specify bandwidth = 1/10 of link capacity Increase EIGRP utilization to 50% of actual VC capacity,Configure lowest CIR virtual circuit as point-to-point, specify bandwidth = CIR. Configure higher CIR virtual circuits as multi
13、point, combine CIRs.,EIGRP WAN Configuration: Hybrid Multipoint,Summary,EIGRP performs automatic network-boundary summarization, but administrators can disable automatic summarization and perform manual route summarization on an interface-by-interface basis. Summarizing routes creates smaller routin
14、g tables. Use the no auto-summary command to disable automatic summarization. Use the ip summary-address eigrp command to create a summary address. EIGRP performs equal-cost load balancing by default for up to four paths (up to six paths can be supported). Use the variance command to configure unequ
15、al-cost load balancing.,Summary (Cont.),EIGRP uses up to 50 percent of the bandwidth of an interface by default. Because of the inherent differences in the operational characteristics of WAN links, this default may not be the best option for all WAN links. Use the ip bandwidth-percent eigrp command
16、to configure EIGRP bandwidth use across WAN links.,Configuring EIGRP,Configuring EIGRP Authentication,Router Authentication,Many routing protocols support authentication such that a router authenticates the source of each routing update packet that it receives. Simple password authentication is supp
17、orted by: IS-IS OSPF RIPv2 MD5 authentication is supported by: OSPF RIPv2 BGP EIGRP,Simple Password vs. MD5 Authentication,Simple password authentication: Router sends packet and key. Neighbor checks whether key matches its key. Process not secure. MD5 authentication: Configure a key (password) and key ID; router generates a message digest, or hash, of the key, key ID and message. Message digest is sent with packet; key is not sent. Process OS secure.,
