en
conf t

hostname p5r1

ip host p5r1 192.168.5.17 192.168.5.33 192.168.5.49 10.5.5.5
ip host p5r2 192.168.5.65 192.168.5.18 192.168.5.34
ip host p5r3 192.168.5.66 192.168.5.50
ip host bbr2 10.5.5.100

no ip domain-lookup 

line con 0
 exec-timeout 0 0
 logging synchronous

enable secret lmi

interface Serial1/0
 ip address 192.168.5.17 255.255.255.240
 bandwidth 64
 no shutdown

interface Serial1/1
 ip address 192.168.5.33 255.255.255.240
 bandwidth 64
 no shutdown

interface Serial1/2
 ip address 192.168.5.49 255.255.255.240
 bandwidth 64
 no shutdown

interface Serial1/3
 description currently a DTE interface
 ip address 10.5.5.5 255.255.255.0
 bandwidth 64
 no shutdown

router eigrp 200
 network 192.168.5.0 
 network 10.0.0.0

line vty 0 4
 login
 password lmi
end
 
copy run start


_______________________




p5r1

p5r1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
p5r1(config)#router eigrp 200
p5r1(config-router)#no auto-summary
p5r1(config-router)#^Z


bbr2#sh ip route

     192.168.5.0/28 is subnetted, 4 subnets
D       192.168.5.64 [90/41049600] via 10.5.5.5, 00:05:24, Serial1/0
D       192.168.5.32 [90/41024000] via 10.5.5.5, 00:05:25, Serial1/0
D       192.168.5.48 [90/41024000] via 10.5.5.5, 00:05:25, Serial1/0
D       192.168.5.16 [90/41024000] via 10.5.5.5, 00:05:25, Serial1/0


p5r1#conf t
p5r1(config)# int s 1/3
p5r1(config-if)#ip summary-address eigrp 200 192.168.5.0 255.255.255.128
p5r1(config-if)#^Z
p5r1#

bbr2#sh ip route

     192.168.5.0/25 is subnetted, 1 subnets
D       192.168.5.0 [90/41024000] via 10.5.5.5, 00:00:47, Serial1/0

___________________
!what happens if we summarize to a /24?

p5r1#conf t
p5r1(config)#int s 1/3
p5r1(config-if)#ip summary-address eigrp 200 192.168.5.0 255.255.255.0
p5r1(config-if)#^Z
p5r1#


bbr2#sh ip route

D       192.168.5.0/24 [90/41024000] via 10.5.5.5, 00:00:03, Serial1/0
D       192.168.5.0/25 [90/41024000] via 10.5.5.5, 00:00:03, Serial1/0

!both routes show up
 
bbr2#ping 192.168.5.66

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.5.66, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/5/8 ms

____________________


p5r1#conf t
p5r1(config)#int s 1/3
p5r1(config-if)#no ip summary-address eigrp 200 192.168.5.0 255.255.255.128
p5r1(config-if)#^Z
p5r1#

bbr2#sh ip route

D    192.168.5.0/24 [90/41024000] via 10.5.5.5, 00:01:28, Serial1/0
     10.0.0.0/24 is subnetted, 4 subnets

bbr2#ping 192.168.5.66

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.5.66, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/8 ms