In this lab we'll set up four routers with varying link speeds, and then enable EIGRP.

Network Diagram:

The first thing we need to do is configure our routers interfaces. the lower path between R0 and R1 is using Ethernet/FastEthernet, and the high path is using serial connections. Lets start with the high path serial connections. Because these are serial links we also need to set up the clock rate on the DCE end of the cable.

R0(config)#interface serial 1/0
R0(config-if)#ip address 10.3.3.1 255.255.255.252
R0(config-if)#clock rate 64000
R0(config-if)#no shutdown

R2(config-if)#interface serial 0/0
R2(config-if)#ip address 10.3.3.2 255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#interface serial 0/1
R2(config-if)#ip address 10.3.3.5 255.255.255.252
R2(config-if)#clock rate 64000
R2(config-if)#no shutdown

R1(config)#interface serial 0/0
R1(config-if)#ip address 10.3.3.6 255.255.255.252
R1(config-if)#no shutdown

If your not sure which end of the cable is the DCE, you can use the command show controllers to check:

R2#show controllers serial 0/0
Interface Serial0/0
Hardware is PowerQUICC MPC860
DTE V.35 clocks stopped.
idb at 0x84D82274, driver data structure at 0x84D89A38
SCC Registers:
General [GSMR]=0x2:0x00000030, Protocol-specific [PSMR]=0x8
Events [SCCE]=0x0000, Mask [SCCM]=0x001F, Status [SCCS]=0x06
Transmit on Demand [TODR]=0x0, Data Sync [DSR]=0x7E7E
Interrupt Registers:
Config [CICR]=0x00367F80, Pending [CIPR]=0x04008800
Mask   [CIMR]=0x60204400, In-srv  [CISR]=0x00000000
Command register [CR]=0x600
Port A [PADIR]=0x0400, [PAPAR]=0xFFFF
       [PAODR]=0x0000, [PADAT]=0xF9FF
Port B [PBDIR]=0x03A0F, [PBPAR]=0x0000E
       [PBODR]=0x00000, [PBDAT]=0x3C57D
Port C [PCDIR]=0x00C, [PCPAR]=0x000
       [PCSO]=0x0A0,  [PCDAT]=0xFC0, [PCINT]=0x00F
Receive Ring
    rmd(680126B0): status 9000 length 60C address 7E131E4
    rmd(680126B8): status 9000 length 60C address 7CC0624
    rmd(680126C0): status 9000 length 60C address 7CBFFA4
    rmd(680126C8): status 9000 length 60C address 7CBF924

Once you've got your Serial config done make sure to test the connectivity is working. If it's not make sure you've enabled the interfaces and that you have the clock rate set on the right end of the connections.

R0#ping 10.3.3.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.3.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/29/32 ms

R2#ping 10.3.3.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.3.6, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/32 ms

Next thing we need to do is our lower path of ethernet and fast ethernet links.

R0(config)#interface ethernet 0/0
R0(config-if)#ip address 10.3.3.14 255.255.255.252
R0(config-if)#no shutdown

R1(config)#interface fastethernet 0/0
R1(config-if)#ip address 10.3.3.9 255.255.255.252
R1(config-if)#no shutdown

R3(config-if)#interface fastethernet 0/0
R3(config-if)#ip address 10.3.3.13 255.255.255.252
R3(config-if)#no shutdown
R3(config-if)#interface fastethernet 0/1
R3(config-if)#ip address 10.3.3.10 255.255.255.252
R3(config-if)#no shutdown

Again test connectivity.

R3#ping 10.3.3.9

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.3.3.9, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

Next we'll configure some loopback interfaces which we'll advertise using EIGRP:

R1(config)#interface loopback 0
R1(config-if)#ip address 192.168.30.1 255.255.255.0

R2(config)#interface loopback 0
R2(config-if)#ip address 172.16.1.1 255.255.255.128

R3(config)#interface loopback 0
R3(config-if)#ip address 172.16.1.129 255.255.255.128

R0(config)#interface loopback 0
R0(config-if)#ip address 192.168.10.1 255.255.255.0

Now it's time to configure EIGRP:

R1(config)#router eigrp 100
R1(config-router)#network 192.168.30.0 0.0.0.255
R1(config-router)#network 10.0.0.0

R2(config)#router eigrp 100
R2(config-router)#network 172.16.1.0 0.0.0.127
R2(config-router)#network 10.0.0.0
*Mar  1 08:20:10.109: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.6 (Serial0/1) is up: new adjacency

R0(config)#router eigrp 100
R0(config-router)#network 192.168.10.0 0.0.0.255
R0(config-router)#network 10.0.0.0
*Mar  1 06:27:36.791: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.2 (Serial1/0) is up: new adjacency

R3(config)#router eigrp 100
R3(config-router)#network 172.16.1.128 0.0.0.127
R3(config-router)#network 10.0.0.0
*Mar  1 08:30:01.386: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.9 (FastEthernet0/1) is up: new adjacency
*Mar  1 08:30:01.386: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.14 (FastEthernet0/0) is up: new adjacency

Below is the routing table on R3, once we add the EIGRP config to all the routers. You may notice that is doesn't look quite right. The 172.16.1.0 and 172.16.1.128 networks aren't being advertised correctly. To fix this we need to disable auto-summary.

Gateway of last resort is not set

D    192.168.30.0/24 [90/156160] via 10.3.3.9, 00:01:35, FastEthernet0/1
D    192.168.10.0/24 [90/156160] via 10.3.3.14, 00:01:35, FastEthernet0/0
     172.16.0.0/16 is variably subnetted, 2 subnets, 2 masks
C       172.16.1.128/25 is directly connected, Loopback0
D       172.16.0.0/16 [90/2300416] via 10.3.3.9, 00:00:18, FastEthernet0/1
     10.0.0.0/30 is subnetted, 4 subnets
C       10.3.3.8 is directly connected, FastEthernet0/1
C       10.3.3.12 is directly connected, FastEthernet0/0
D       10.3.3.0 [90/2684416] via 10.3.3.9, 00:01:36, FastEthernet0/1
D       10.3.3.4 [90/2172416] via 10.3.3.9, 00:01:36, FastEthernet0/1

This is R0's routing table before disabling auto-summary:

Gateway of last resort is not set

D    192.168.30.0/24 [90/21152000] via 10.3.3.2, 00:00:12, Serial1/0
C    192.168.10.0/24 is directly connected, Loopback0
D    172.16.0.0/16 [90/20640000] via 10.3.3.2, 00:00:12, Serial1/0
     10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
D       10.3.3.8/30 [90/21026560] via 10.3.3.2, 00:00:12, Serial1/0
C       10.3.3.12/30 is directly connected, Ethernet0/0
C       10.3.3.0/30 is directly connected, Serial1/0
D       10.0.0.0/8 is a summary, 00:00:13, Null0
D       10.3.3.4/30 [90/21024000] via 10.3.3.2, 00:00:14, Serial1/0

Once we disable auto-summary with the below commands our routing table will update with the correct routes.

R2(config)#router eigrp 100
R2(config-router)#no auto-summary
*Mar  1 08:25:20.297: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.1 (Serial0/0) is resync: summary configured
*Mar  1 08:25:20.297: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.6 (Serial0/1) is resync: summary configured

R3(config)#router eigrp 100
R3(config-router)#no auto-summary
*Mar  1 08:31:17.891: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.14 (FastEthernet0/0) is resync: summary configured
*Mar  1 08:31:17.891: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 100: Neighbor 10.3.3.9 (FastEthernet0/1) is resync: summary configured

Now we have a much better looking routing table. Again this routing table is from R3

Gateway of last resort is not set

D    192.168.30.0/24 [90/156160] via 10.3.3.9, 00:00:23, FastEthernet0/1
D    192.168.10.0/24 [90/156160] via 10.3.3.14, 00:00:23, FastEthernet0/0
     172.16.0.0/25 is subnetted, 2 subnets
C       172.16.1.128 is directly connected, Loopback0
D       172.16.1.0 [90/2300416] via 10.3.3.9, 00:00:23, FastEthernet0/1
     10.0.0.0/30 is subnetted, 4 subnets
C       10.3.3.8 is directly connected, FastEthernet0/1
C       10.3.3.12 is directly connected, FastEthernet0/0
D       10.3.3.0 [90/2684416] via 10.3.3.9, 00:00:25, FastEthernet0/1
D       10.3.3.4 [90/2172416] via 10.3.3.9, 00:00:25, FastEthernet0/1

R0's routing table once auto-summary is disabled:

Gateway of last resort is not set

D    192.168.30.0/24 [90/412160] via 10.3.3.13, 00:00:35, Ethernet0/0
C    192.168.10.0/24 is directly connected, Loopback0
     172.16.0.0/25 is subnetted, 2 subnets
D       172.16.1.128 [90/409600] via 10.3.3.13, 00:00:35, Ethernet0/0
D       172.16.1.0 [90/2326016] via 10.3.3.13, 00:00:35, Ethernet0/0
     10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks
D       10.3.3.8/30 [90/284160] via 10.3.3.13, 00:00:35, Ethernet0/0
C       10.3.3.12/30 is directly connected, Ethernet0/0
C       10.3.3.0/30 is directly connected, Serial1/0
D       10.0.0.0/8 is a summary, 00:07:34, Null0
D       10.3.3.4/30 [90/2198016] via 10.3.3.13, 00:00:36, Ethernet0/0

Once you've completed the EIGRP config make sure to test your connectivity:

R3#ping 172.16.1.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 172.16.1.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/29/32 ms
R3#ping 192.168.10.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.10.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/3/4 ms
R3#ping 192.168.30.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.30.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/2/4 ms

A gotchya to watch out for in this lab. If you're connecting your Ethernet/FastEthernet interfaces into a switch without any segregation meaning all connections are in the same VLAN you will recieve messages similar to the following:

*Mar  1 08:32:42.710: IP-EIGRP(Default-IP-Routing-Table:100): Neighbor 10.3.3.9 not on common subnet for FastEthernet0/0
*Mar  1 08:32:53.356: IP-EIGRP(Default-IP-Routing-Table:100): Neighbor 10.3.3.14 not on common subnet for FastEthernet0/1
*Mar  1 06:35:20.583: IP-EIGRP(Default-IP-Routing-Table:100): Neighbor 10.3.3.10 not on common subnet for Ethernet0/0
*Mar  1 06:35:48.171: IP-EIGRP(Default-IP-Routing-Table:100): Neighbor 10.3.3.9 not on common subnet for Ethernet0/0

In order to get to stop this you need to place R0's E0/0 and R3's FE0/0 interfaces in one VLAN and R3's FE0/1 and R1's FE0/0 interfaces in another VLAN.