1. Rick Graziani Cabrillo College graziani@cabrillo.edu
Fine Tuning EIGRP
Rick Graziani
Cabrillo College

2. EIGRP: IPv4 Automatic Summarization
Rick Graziani
Cabrillo College

3. EIGRP (IPv4) Network Topology

4. R1# show running-config
interface GigabitEthernet0/0
ip address !
interface Serial0/0/0
bandwidth 64
ip address
clock rate 64000
interface Serial0/0/1
ip address
router eigrp 1
eigrp router-id
network
network

5. R2# show running-config
interface GigabitEthernet0/0
ip address !
interface Serial0/0/0
bandwidth 64
ip address
interface Serial0/0/1
bandwidth 1024
ip address
clock rate 64000
interface Serial0/1/0
ip address
router eigrp 1
eigrp router-id
network
network

6. R3# show running-config
interface GigabitEthernet0/0
ip address !
interface Serial0/0/0
ip address
clock rate 64000
interface Serial0/0/1
bandwidth 1024
ip address
router eigrp 1
eigrp router-id
network
network
network

7. Route Summarization Route summarization:
Groups contiguous networks together
Advertises them using a single summarized route
Summarization:
Decreases the number of entries in routing updates
Reduces bandwidth utilization for routing updates
Results in faster routing table lookups.
EIGRP for IPv4 includes both automatic (classful boundary) and manual summarization
EIGRP for IPv6 is only manual summarization as there are no classes in IPv6.

8. I’m an EIGRP for IPv4 router configured for automatic summarization.
Automatic Summarization at Classful Network Boundary
I’m an EIGRP for IPv4 router configured for automatic summarization.
IPv4 Routing Table
/24
/24
/24
/30 R1 R2
/16 via R1
Summary Update: /16
Classful Networks
Class A: to Default Mask: or /8
Class B: to Default Mask: or /16
Class C: to Default Mask: or /24
When enabled, EIGRP summarizes at classful boundaries.
EIGRP groups subnets into their Class A, B, or C network address and creates a single entry.
Media Description:
Use graphic from powerpoint

9. EIGRP for IPv4 automatic summarization defaults
Since IOS 15.0(1)M and 12.2(33), automatic summarization is disabled.
IPv6 does not have classful networks so there is no automatic summarization for IPv6.
R1(config-router)# no auto-summary
Prior, automatic summarization was enabled.
R1(config-router)# auto-summary
/24
/14
/24
/24
/14
/24
R3# show ip route eigrp
<Output omitted>
/16 is variably subnetted, 3 subnets, 2 masks
D /24 [90/ ] via , 02:21:10, Serial0/0/0
D /24 [90/ ] via , 02:21:10, Serial0/0/1
D /30 [90/ ] via , 02:21:10, Serial0/0/1
[90/ ] via , 02:21:10, Serial0/0/0
R3#

10. Verifying EIGRP Automatic Summarization
R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Default networks flagged in outgoing updates
Default networks accepted from incoming updates
EIGRP-IPv4 Protocol for AS(1)
Metric weight K1=1, K2=0, K3=1, K4=0, K5=0
<Output omitted>
Automatic Summarization: disabled
Maximum path: 4
Routing for Networks:
Media Description:
Use graphic from powerpoint

11. When automatic summarization is enabled:
EIGRP for IPv4 automatically summarizes network addresses between different major class networks.
/16
/16
R1(config)# router eigrp 1
R1(config-router)# auto-summary
R1(config-router)#
*Mar 9 19:40:19.342: %DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor (Serial0/0/1) is resync: summary configured
*Mar 9 19:40:19.342: %DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor (Serial0/0/1) is resync: summary up, remove components
*Mar 9 19:41:03.630: %DUAL-5-NBRCHANGE: EIGRP-IPv4 1: Neighbor (Serial0/0/1) is resync: peer graceful-restart
R2(config)# router eigrp 1
R2(config-router)# auto-summary
R3(config)# router eigrp 1
R3(config-router)# auto-summary

12. Verifying Auto-Summary: Routing Table
Automatic Summarization Disabled
R3# show ip route eigrp
<Output omitted>
/16 is variably subnetted, 3 subnets, 2 masks
D /24 [90/ ] via , 02:21:10, Serial0/0/0
D /24 [90/ ] via , 02:21:10, Serial0/0/1
D /30 [90/ ] via , 02:21:10, Serial0/0/1
[90/ ] via , 02:21:10, Serial0/0/0
Automatic Summarization Enabled
R3# show ip route eigrp
<Output omitted>
D /16 [90/ ] via , 00:12:05, Serial0/0/0
/24 is variably subnetted, 5 subnets, 3 masks
D /24 is a summary, 00:11:43, Null0
Media Description:
Use graphic from powerpoint

13. Verifying Auto-Summary: Topology Table
Feasible Successor
Verifying Auto-Summary: Topology Table
/16
Successor
/16
R3# show ip eigrp topology all-links
P /16, 1 successors, FD is , serno 9
via ( /2816), Serial0/0/0
via ( /2816), Serial0/0/1
<Output omitted>
Successor
Feasible Successor
Media Description:
Use graphic from powerpoint

14. Verifying Auto-Summary: show ip protocols
/24
/16
R1# show ip protocols
*** IP Routing is NSF aware ***
<Output omitted>
Automatic Summarization: enabled
/24 for Gi0/0, Se0/0/0
Summarizing 2 components with metric
/16 for Se0/0/1
Summarizing 3 components with metric 2816
Media Description:
Use graphic from powerpoint

15. 172.16.0.0/16 is variably subnetted, 6 subnets, 4 masks
The purpose of the Null0 summary route is to prevent routing loops for destinations that are included in the summary, but do not actually exist in the routing table. "If I don't know the subnet, then I will drop the packet because the subnet doesn't exist."
/24
/16
R1# show ip route
/16 is variably subnetted, 6 subnets, 4 masks
D /16 is a summary, 00:03:06, Null0
C /24 is directly connected, GigabitEthernet0/0
L /32 is directly connected, GigabitEthernet0/0
D /24 [90/ ] via , 00:02:52, Serial0/0/0
C /30 is directly connected, Serial0/0/0
L /32 is directly connected, Serial0/0/0
D /24 [90/ ] via , 00:02:51, Serial0/0/1
/24 is variably subnetted, 4 subnets, 3 masks
D /24 is a summary, 00:02:52, Null0
<output omitted>
Media Description:
Use graphic from powerpoint

16. Routing Update: Default Route
Example of a Routing Loop 9
Routing loop 7
I have a summary route for /16. I will send packets for to Router B. 8
I have a default route /0. I will send packets for to Router A.
IPv4 Routing Table
IPv4 Routing Table 2
Routing Update: Default Route
/0 via
RouterA
/24
/24
/24 1
/0 via
ISP
/16
Via RouterB 3
RouterA
RouterB 5 4
Summarized Update: /16 6
Internet
ISP
Media Description:
Use graphic from powerpoint

17. Routing Update: Default Route
Null0 Route is used for Loop Prevention 9 8
I have a summary route for /16. I will send packets for to Router B.
I have a summary route for /16 via Null0. I drop packets for
IPv4 Routing Table
IPv4 Routing Table 2
Routing Update: Default Route
/0 via
RouterA
/24
/24
/24
/16
via Null0 1
/0 via
ISP
/16
Via RouterB 3
RouterA
RouterB 6 4
Summarized Update: /16 7 5
Internet
ISP
Media Description:
Use graphic from powerpoint

18. EIGRP: IPv4 Automatic Summarization
Rick Graziani
Cabrillo College

19. EIGRP: IPv4 Manual Summarization
Rick Graziani
Cabrillo College

20. Manual Route Summarization
EIGRP manual summary routes used with or without auto-summary
EIGRP is a classless routing protocol - includes the subnet mask in the routing updates
Manual summarization can include supernet routes.
A supernet is an aggregation of multiple major classful network addresses
EIGRP manual summarization is configured on a specific EIGRP interface:
ip summary-address eigrp as-number network-address subnet-mask

21. Loopback’s Added for Demonstration
R3(config)# interface loopback 2
R3(config-if)# ip add
R3(config-if)# exit
R3(config)# interface loopback 3
R3(config-if)# ip add
R3(config)# router eigrp 1
R3(config-router)# network
R3(config-router)# network

22. Additional Routes Verified on R1 and R2
R1# show ip route
<Output omitted>
D /24 [90/ ] via , 00:47:39, Serial0/0/1
D /24 [90/ ] via , 00:08:09, Serial0/0/1
D /24 [90/ ] via , 00:08:04, Serial0/0/1
R2# show ip route
<Output omitted>
D /24 [90/ ] via , 00:47:58, Serial0/0/1
D /24 [90/ ] via , 00:08:28, Serial0/0/1
D /24 [90/ ] via , 00:08:23, Serial0/0/1
Media Description:
Use graphic from powerpoint

23. Calculating a Summary Route
Use the same method is used to determine summary static routes:
Write out the networks to be summarized in binary.
To find the subnet mask for summarization, start with the far left bit.
Working from left to right, find all the bits that match consecutively.
ip summary-address eigrp
Media Description:
Use graphic from E , “R3 Summary route” button as modified in powerpoint

24. Calculating a Summary Route
/22
/22
Calculating a Summary Route
R3(config)# interface serial 0/0/0
R3(config-if)# ip summary-address eigrp
R3(config)# interface serial 0/0/1
Media Description:
Use graphic from E , “R3 Summary route” button as modified in powerpoint

25. Verifying Summary Route Received on R1 and R2
Note: A Null Summary Route is added to R3’s routing table (not shown here).
/22
/22
Verifying Summary Route Received on R1 and R2
R1# show ip route
<Output omitted>
D /22 [90/ ] via , 01:53:19, Serial0/0/1
R1#
R2# show ip route
<Output omitted>
D /22 [90/ ] via , 01:53:33, Serial0/0/1
R2#
Media Description:
Use graphic from powerpoint

26. EIGRP: IPv4 Manual Summarization
Rick Graziani
Cabrillo College

27. EIGRP: IPv6 Manual Summarization
Rick Graziani
Cabrillo College

28. EIGRP for IPv6 Topology

29. Configure Loopbacks and enable EIGRP for IPv6 on each interface
R3(config)# interface loopback 11
R3(config-if)# ipv6 address 2001:db8:acad:1::1/64
R3(config-if)# ipv6 eigrp 2
R3(config-if)# exit
R3(config)# interface loopback 12
R3(config-if)# ipv6 address 2001:db8:acad:2::1/64
R3(config)# interface loopback 13
R3(config-if)# ipv6 address 2001:db8:acad:3::1/64
R3(config)# interface loopback 14
R3(config-if)# ipv6 address 2001:db8:acad:4::1/64

30. Manual Route Summarization
EIGRP manual summarization can also be configured on IPv6.
Configured on a specific EIGRP interface:
ipv6 summary-address eigrp as-number prefix/prefix-length

31. Identify Where the Addresses Differ
Media Description:
Use the media from E A

32. Convert the Section from Hex to Binary
Media Description:
Use the media from E A

33. Count the # of Left-Most Matching Bits
Add Zero Bits
Media Description:
Use the media from E A

34. Convert the Binary Section Back to Hex
2001:0DB8:ACAD:0000::/61 or
2001:0DB8:ACAD:0::/61
2001:0DB8:ACAD::/61
Media Description:
Use the media from E A

35. Configuration and Verification of EIGRP for IPv6 Manual Summary Route
A Null Summary Route is added to R3’s routing table.
2001:db8:acad::/61
Configuration and Verification of EIGRP for IPv6 Manual Summary Route
2001:db8:acad::/61
R3(config)# interface serial 0/0/0
R3(config-if)# ipv6 summary-address eigrp :db8:acad::/61
R3(config-if)# exit
R3(config)# interface serial 0/0/1
R3(config-if)# end
R3# show ipv6 route
D :DB8:ACAD::/61 [5/128256]
via Null0, directly connected
<Output omitted>
Media Description:
Use graphic from powerpoint

36. Verification of EIGRP for IPv6 Manual Summary Route
2001:db8:acad::/61
2001:db8:acad::/61
Verification of EIGRP for IPv6 Manual Summary Route
R1# show ipv6 route | include 2001:DB8:ACAD:
D :DB8:ACAD::/61 [90/ ]
R1#
Media Description:
Use graphic from powerpoint

37. EIGRP: IPv6 Manual Summarization
Rick Graziani
Cabrillo College

38. EIGRP: Propagating a Default Route
Rick Graziani
Cabrillo College

39. EIGRP for IPv4: Default Route to ISP

40. Propagating a Default Route
Default Static Route
Propagating a Default Route
Redistribute static
Redistribute static
R2(config)# ip route
R2(config)# router eigrp 1
R2(config-router)# redistribute static
To create a default static route:
ip route next-hop | interface
To propagate the default route into the EIGRP AS, use the:
redistribute static router configuration command.
Note:
EIGRP also supports propagating the default route using the ip default-network network-number global configuration command, but not recommended.

41. R2’s Default Static Route
Redistribute static
Redistribute static
R2’s Default Static Route
R2# show ip route | include
Gateway of last resort is to network
S* /0 via , 00:25:23, Serial0/1/0
R2# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Default networks flagged in outgoing updates
Default networks accepted from incoming updates
Redistributing: static
EIGRP-IPv4 Protocol for AS(1)
<Output omitted>
Media Description:
Use graphic from powerpoint

42. Verifying Default Route on R1 and R3
Default Static Route
Redistribute static
Redistribute static
Verifying Default Route on R1 and R3
R1# show ip route | include
Gateway of last resort is to network
D*EX /0 [170/ ] via , 00:25:23, Serial0/0/1
R1#
R3# show ip route | include
Gateway of last resort is to network
D*EX /0 [170/ ] via , 00:27:17, Serial0/0/1
R3#
Media Description:
Use graphic from powerpoint

43. EIGRP for IPv6: Default Route

44. R2 IPv6 Static Default Route Configuration and Propagation
Default Static Route
Redistribute static
Redistribute static
R2 IPv6 Static Default Route Configuration and Propagation
R2(config)# ipv6 route ::/0 2001:db8:feed:a002::2
R2(config)# ipv6 router eigrp 2
R2(config-router)# redistribute static
Verifying Default Route on R1 and R3
R1# show ipv6 route
Codes: C EX - EIGRP external
EX ::/0 [170/ ]
via FE80::3, Serial0/0/1
Media Description:
Use graphic from powerpoint

45. Alternative method using a summary route
Default Static Route
Alternative method using a summary route
Summary Route
Summary Route
R2(config)# ipv6 route ::/0 2001:db8:feed:a002::2
R2(config)# interface serial 0/1/0
R2(config-if)# ipv6 summary-address eigrp 2 ::/0
R2(config)# ip route
R2(config)# interface serial 0/1/0
R2(config-if)# ip summary-address eigrp
Media Description:
Use graphic from powerpoint

46. EIGRP: Propagating a Default Route
Rick Graziani
Cabrillo College

47. EIGRP: Bandwidth Utilization
Rick Graziani
Cabrillo College

48. EIGRP ip bandwith-percent
By default, EIGRP is set to use up to 50% of the bandwidth of an interface to exchange routing information.
The ip bandwidth-percent eigrp command or the ipv6 bandwidth-percent eigrp command can be configured to control the amount of bandwidth available to EIGRP.
This is not the same as the bandwidth command.
However, this command relies on the value set by the bandwidth command.

49. Configuring Bandwidth Utilization with EIGRP for IPv4
R1(config)# interface serial 0/0/0
R1(config-if)# bandwidth 64
R1(config-if)# ip bandwidth-percent eigrp 1 40
R1(config-if)#
R2(config)# interface serial 0/0/0
R2(config-if)# bandwidth 64
R2(config-if)# ip bandwidth-percent eigrp 1 40
R2(config-if)#
Media Description:
Use graphic from powerpoint

50. Configuring Bandwidth Utilization with EIGRP for IPv6
64 kb/s
Configuring Bandwidth Utilization with EIGRP for IPv6
R1(config)# interface serial 0/0/0
R1(config-if)# ipv6 bandwidth-percent eigrp 2 40
R1(config-if)#
R2(config)# interface serial 0/0/0
R2(config-if)# ipv6 bandwidth-percent eigrp 2 40
R2(config-if)#
Media Description:
Use graphic from powerpoint

51. EIGRP: Bandwidth Utilization
Rick Graziani
Cabrillo College

52. EIGRP: Hello and Hold Timers
Rick Graziani
Cabrillo College

53. Configuring Hello Intervals and Hold Times
Router(config-if)# ip hello-interval eigrp as-number seconds
Router(config-if)# ip hold-time eigrp as-number seconds
Hello intervals and hold times do not have to match with other EIGRP routers to establish adjacencies.
We will see later, OSPF’s Hello and other timers do need to match between neighbors.
Range from 1 to 65,535
If you change the hello interval, make sure that you also change the hold time to a value greater than the hello interval.
Otherwise, neighbor adjacency will go down after the hold time expires and before the next hello interval.
Hello intervals and hold times are configurable on a per-interface basis and do not have to match with other EIGRP routers to establish adjacencies.
We will see later, OSPF’s Hello and other timers do need to match.
The seconds value for both hello and holdtime intervals can range from 1 to 65,535
If you change the hello interval, make sure that you also change the hold time to a value equal to or greater than the hello interval.
Otherwise, neighbor adjacency will go down after the hold time expires and before the next hello interval.

54. Configuring EIGRP for IPv4 Hello and Hold Timers
R1(config)# interface serial 0/0/0
R1(config-if)# ip hello-interval eigrp 1 60
R1(config-if)# ip hold-time eigrp 1 180
R2(config)# interface serial 0/0/0
R2(config-if)# ip hello-interval eigrp 1 60
R2(config-if)# ip hold-time eigrp 1 180
Media Description:
Use graphic from powerpoint
Use Table from E

55. Configuring EIGRP for IPv6 Hello and Hold Timers
R1(config)# inter serial 0/0/0
R1(config-if)# ipv6 hello-interval eigrp 2 60
R1(config-if)# ipv6 hold-time eigrp 2 180
R2(config)# inter serial 0/0/0
R2(config-if)# ipv6 hello-interval eigrp 2 60
R2(config-if)# ipv6 hold-time eigrp 2 180
Media Description:
Use graphic from powerpoint

56. EIGRP: Hello and Hold Timers
Rick Graziani
Cabrillo College

57. EIGRP: Load Balancing Rick Graziani Cabrillo College

58. Referred to as “equal-cost load balancing”.
R3# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
<Output omitted>
Distance: internal 90 external 170
Maximum path: 4
Maximum hopcount 100
Maximum metric variance 1
Automatic Summarization: disabled
Address Summarization:
/22 for Se0/0/0, Se0/0/1
Summarizing 3 components with metric 2816
Routes with a metric equal to the minimum metric are installed in the routing table.
Referred to as “equal-cost load balancing”.
All IP routing protocols on Cisco routers can perform equal-cost load balancing.
The maximum-paths maximum-path command can be used to allow up to 6 equal-cost paths.
Default is 4.
Setting the maximum-path option to 1 disables load balancing.
Media Description:
Use graphic from powerpoint

59. R3 has equal cost paths to 172. 16. 3
R3 has equal cost paths to /30 because 64 kb/s is the slowest bandwidth used for the metric.
R3# show ip route eigrp
<Output omitted>
Gateway of last resort is to network
D*EX /0 [170/ ] via , 00:14:24, Serial0/0/1
/16 is variably subnetted, 3 subnets, 2 masks
D /24 [90/ ] via , 00:14:28, Serial0/0/0
D /24 [90/ ] via , 00:14:24, Serial0/0/1
D /30 [90/ ] via , 00:14:24, Serial0/0/1
[90/ ] via , 00:14:24, Serial0/0/0
D /22 is a summary, 00:14:40, Null0
Media Description:
Use graphic from powerpoint

60. R3’s IPv6 Routing Table R3# show ipv6 route eigrp
<Output omitted>
EX ::/0 [170/ ]
via FE80::2, Serial0/0/1
D :DB8:ACAD::/48 [5/128256]
via Null0, directly connected
D :DB8:CAFE:1::/64 [90/ ]
via FE80::1, Serial0/0/0
D :DB8:CAFE:2::/64 [90/ ]
D :DB8:CAFE:A001::/64 [90/ ]
R3#
Media Description:
Use graphic from powerpoint

61. EIGRP: Load Balancing Rick Graziani Cabrillo College

62. EIGRP: Authentication
Rick Graziani
Cabrillo College

63. Router Authentication
Many routing protocols support authentication.
This means that a router authenticates the source of each routing update packet that it receives.
Without authentication, an attacker could introduce different or conflicting route information to corrupt the router resulting in a DoS attack.
Neighbor router authentication (also called route authentication) can be configured such that routers only participate in routing based on predefined passwords.
By default, no authentication is used for routing protocol packets. When neighbor router authentication has been configured on a router, the router authenticates the source of each routing update packet that it receives, which is accomplished by the exchange of an authentication key (also called a password) that is known to both the sending and the receiving router.
There are two types of authentication: simple password authentication (also called plain text authentication) and MD5 authentication.
Simple password authentication is supported by Integrated System-Integrated System (IS-IS), Open Shortest Path First (OSPF), and Routing Information Protocol version 2 (RIPv2). MD5 authentication is supported by OSPF, RIPv2, Border Gateway Protocol (BGP), and EIGRP.
NOTE: Authentication for EIGRP, OSPF, and BGP is covered in this course.

64. EIGRP MD5 Authentication
EIGRP supports MD5 authentication.
Router authenticates the source of each routing update packet that it receives.
Configure a “key” (password) and key-id; each participating neighbor must have same key configured.
EIGRP neighbor authentication (also called neighbor router authentication or route authentication) can be configured such that routers can participate in routing based on predefined passwords.
By default, no authentication is used for EIGRP packets. EIGRP can be configured to use MD5 authentication.
When neighbor authentication has been configured on a router, the router authenticates the source of each routing update packet that it receives. For EIGRP MD5 authentication, an authenticating key (sometimes referred to as a password) and a key-id must be configured on both the sending and the receiving router.

65. EIGRP MD5 Authentication Example
R3 needs to send an update to R1.
Routing Updates Authenticated
Compare Signatures
Signatures
Match!
R3 processes the routing update (data) and key using MD5 to compute a hash signature.
The update is sent to R1 and includes the signature.
R3 repeats the MD5 process using its own key and the received data.

66. Step 1: Create a Keychain
Router(config)# key chain name-of-chain
Router(config-keychain)# key key-id
Router(config-keychain-key)# key-string key-string-text
Before authentication is enabled, create a keychain and key.
Multiple keys can be configured.
Specify the key ID using a range of keys (0 to 2,147,483,647).
Recommended to use the same key number on all routers.
Enable EIGRP authentication on an interface and identify the keychain and key to use.
Specify the keychain that should be used for authentication.
The keychain and the routing update are processed using the MD5 algorithm to produce a unique signature.
Step 2: Configure EIGRP Authentication Using Keychain and Key
Router(config)# interface type number
Router(config-if)# ip authentication mode eigrp as-number md5
Router(config-if)# ip authentication key-chain eigrp as-number name-of-chain
Media Description:
Use graphic from powerpoint

67. Similar configuration for R3.
Configuring EIGRP MD5 Authentication on R1
Similar configuration for R3.
R1(config)# key chain EIGRP_KEY
R1(config-keychain)# key 1
R1(config-keychain-key)# key-string cisco123
R1(config-keychain-key)# exit
R1(config-keychain)# exit
R1(config)# interface serial 0/0/0
R1(config-if)# ip authentication mode eigrp 1 md5
R1(config-if)# ip authentication key-chain eigrp 1 EIGRP_KEY
R1(config-if)# exit
R1(config)# interface serial 0/0/1
R2(config)# key chain EIGRP_KEY
R2(config-keychain)# key 1
R2(config-keychain-key)# key-string cisco123
R2(config-keychain-key)# exit
R2(config-keychain)# exit
R2(config)# interface serial 0/0/0
R2(config-if)# ip authentication mode eigrp 1 md5
R2(config-if)# ip authentication key-chain eigrp 1 EIGRP_KEY
R2(config-if)# exit
R2(config)# interface serial 0/0/1
Media Description:
Use graphic from powerpoint

68. Configuring EIGRP for IPv6 MD5 Authentication on R1
R1(config)# key chain EIGRP_IPV6_KEY
R1(config-keychain)# key 1
R1(config-keychain-key)# key-string cisco123
R1(config-keychain-key)# exit
R1(config-keychain)# exit
R1(config)# interface serial 0/0/0
R1(config-if)# ipv6 authentication mode eigrp 2 md5
R1(config-if)# ipv6 authentication key-chain eigrp 2 EIGRP_IPV6_KEY
R1(config-if)# exit
R1(config)# interface serial 0/0/1
R1(config-if)#
Media Description:
Use graphic from powerpoint

69. Verify EIGRP MD5 Authentication on R1
R1# show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
Se0/0/ :28:
Se0/0/ :28:
R2# show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
Se0/0/ :22:
Se0/0/ :51:
R3# show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
Se0/0/ :21:
Se0/0/ :51:
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70. EIGRP: Authentication
Rick Graziani
Cabrillo College

71. EIGRP: Troubleshooting
Rick Graziani
Cabrillo College

72. EIGRP Troubleshooting Commands
Several commands that are useful when troubleshooting an EIGRP network.
show ip eigrp neighbors command verifies that the router recognizes its neighbors.
show ip route command verifies that the router learned the route to a remote network through EIGRP.
show ip protocols command verifies the EIGRP configured values for various properties of any enabled routing protocols.
Similar commands and troubleshooting criteria also apply to EIGRP for IPv6.
show ipv6 eigrp neighbors
show ipv6 route
show ipv6 protocols

73. Diagnosing EIGRP Connectivity Issues
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74. Troubleshooting Neighbor Issues
The equivalent command used with EIGRP for IPv6 is:
show ipv6 interface brief
Troubleshoot EIGRP Neighbor Issues
R1# show ip interface brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/ YES manual up up
Serial0/0/ YES manual up up
Serial0/0/ YES manual up up
R1# ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 28/28/28 ms
R1#
Media Description:
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75. Troubleshoot EIGRP Neighbor Issues
The equivalent command used with EIGRP for IPv6 is:
show ipv6 protocols
Troubleshoot EIGRP Neighbor Issues
R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1“
R2# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1“
31# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1“
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76. Troubleshoot EIGRP Neighbor Issues
The equivalent command used with EIGRP for IPv6 is:
show ipv6 eigrp interfaces
Troubleshoot EIGRP Neighbor Issues
R1# show ip eigrp interfaces
EIGRP-IPv4 Interfaces for AS(1)
Xmit Queue PeerQ Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable Un/Reliable SRTT Un/Reliable Flow Timer Routes
Gi0/ / / /
Se0/0/ / / /
Se0/0/ / / /
R1#
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77. Troubleshoot EIGRP Neighbor Issues
The equivalent command used with EIGRP for IPv6 is:
show ipv6 protocols
Troubleshoot EIGRP Neighbor Issues
R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
<Output omitted>
Routing for Networks:
Passive Interface(s):
GigabitEthernet0/0
Routing Information Sources:
Gateway Distance Last Update
:42:31
:42:31
Distance: internal 90 external 170
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78. Troubleshoot EIGRP Neighbor Issues
R1# show running-config | section eigrp 1
router eigrp 1
network
network
passive-interface GigabitEthernet0/0
eigrp router-id
R1#
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79. Troubleshooting A Passive Interface
The equivalent command used with EIGRP for IPv6 is:
show ipv6 protocols
Troubleshoot EIGRP Routing Table Issues
R2# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1“
<Output omitted>
Routing for Networks:
/30
Passive Interface(s):
GigabitEthernet0/0
Routing Information Sources:
<output omitted>
Make sure passive-interface is on the correct interface or adjacencies will not be formed and routing information will not be distributed.
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80. Configuring Network to ISP as a Passive Interface
R2(config)# router eigrp 1
R2(config-router)# network
R2(config-router)# passive-interface serial 0/1/0
R2(config-router)# end
R2# show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
Se0/0/ :09:
Se0/0/ :09:
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81. Verifying Network to ISP is distributed using EIGRP
R1# show ip route | include
D [90/ ] via , 00:06:02,Ser0/0/1
R1#
Media Description:
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82. Troubleshooting A Missing Network Statement
/24 Unreachable from R3
R3# ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R3#

83. /24 Unreachable from R3
R1# show ip protocols | begin Routing for Networks
Routing for Networks:
Passive Interface(s):
GigabitEthernet0/0
Routing Information Sources:
Gateway Distance Last Update
:34:19
:34:19
Distance: internal 90 external 170
Media Description:
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84. R1(config)# router eigrp 1 R1(config-router)# network 10.0.0.0
R3# show ip route | include
D [90/ ] via , 00:04:14, Serial0/0/0
R3#
R3# ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/27/28 ms
Media Description:
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85. Troubleshooting Auto-Summarization
The equivalent command used with EIGRP for IPv6 is:
show ipv6 route
Discontiguous networks - Reachability issues
R2# show ip route
<Output omitted>
/8 is subnetted, 1 subnets
D [90/ ] via , 00:02:06, Serial0/0/1
[90/ ] via , 00:02:06, Serial0/0/0

86. R1(config)# router eigrp 1
R1(config-router)# network
R1(config-router)# network
R1(config-router)# auto-summary
R3(config)# router eigrp 1
R3(config-router)# network
R3(config-router)# network
R3(config-router)# auto-summary

87. R1# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Automatic Summarization: enabled
/8 for Se0/0/0
Summarizing 1 component with metric 28160
<Output omitted>
R3# show ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "eigrp 1"
Automatic Summarization: enabled
/8 for Se0/0/1
Summarizing 1 component with metric 28160
<Output omitted>

88. R1(config)# router eigrp 1 R1(config-router)# no auto-summary
/24
/24
R1(config)# router eigrp 1
R1(config-router)# no auto-summary
R3(config)# router eigrp 1
R3(config-router)# no auto-summary
R2# show ip route
<Output omitted>
/24 is subnetted, 2 subnets
D [90/ ] via , 00:00:27, Serial0/0/0
D [90/ ] via , 00:00:11,Serial0/0/1

89. EIGRP: Troubleshooting
Rick Graziani
Cabrillo College