What is Stuck In Active (EIGRP)?

Stuck In Active (EIGRP)

The EIGRP convergence is the process when going active on a route is sometimes also by the name of the underlying algorithm, diffusing update algorithm (DUAL).

When a successor path is lost and there is no feasible successor is identified, the EIGRP router sends out queries on all interfaces in an attempt to identify an alternate path. EIGRP routers don’t select the successor until the EIGRP router receives a reply to all queries. When a router has received a reply for all its query messages, that router can safely use the best of the routes confirmed to be loop-free. The process can and does work well in many cases, often converging to a new route in less than 10 seconds.  If a reply is missing for 3 minutes, the router becomes stuck in active (SIA). In that case, it reset the neighbor's relationship with the neighbors that did not reply to queries.

EIGRP sends every query and reply message using RTP, so every message is acknowledged using the EIGRP ACK message.

To limit the scope of queries, there are two tools: stub routers and route summarization this us to reduce the work performed by the DUAL and the scope of query messages.

EIGRP STUB

Stub routing is one way to limit queries. A stub router is one that is connected to more than two neighbors and should be a transit router. The EIGRP stub routing feature improves network stability, reduces resource utilization, and simplifies remote router (spoke) configuration. Stub routing is commonly used in a Hub-and-Spoke topology.

Here is the command:

R1(config-router)#EIGRP STUB?

  connected       Do advertise connected routes

  leak-map        Allow dynamic prefixes based on the leak-map

  receive-only    Set receive only neighbor

  redistributed   Do advertise redistributed routes

  static                 Do advertise static routes

  summary         Do advertise summary routes

·         Connected means the router advertises connected routes only for those interfaces that match with a network command.

·         Leak-map means the router advertises only which is specified by a leak-map

·         Receive-only means the router does not advertise any routes. This option can be used with any other option.

·         Redistribution means the router advertises only the redistributed routes.

·         Static means the router advertises only the static routes with redistributed static commands configured.

·         Summary means the router advertises only auto-summarized or statically configured summary routes

NOTE: By default, is connected and summary.

Before we start EIGRP configuration check out some important of EIGRP CCIE exam topics.

Here are the lists of all EIGRP labs and theories CCNA to CCIE

1.Enhanced Interior Gateway Routing Protocol (EIGRP)

2.Stuck In Active (EIGRP)

3.EIGRP Equal-Cost and Unequal-Cost load balancing

4.Route filtering passive interface

5.Route summarization

6.EIGRP STUB and Configuration

7.Routing Protocol Authentication (EIGRP ) and configuration

 

 

Instagram

YouTube

Facebook

Twitter

LINKEDIN

What is EIGRP Equal-Cost and Unequal-Cost load balancing? What is variance? How to configure?

EIGRP Equal-Cost and Unequal-Cost load balancing

Routes with the lowest metric get installed in the routing table by default, if two or more routes have the same metric the router will install both the routes in the routing table this is called equal cost load balancing.

EIGRP does equal cost load balancing automatically, whereas unequal cost load balancing is not automatic, for unequal cost load balancing we need to enable Variance. EIGRP can load balancing up to six paths, and the default is four paths. 

The maximum number of paths are based on Cisco IOS versions and router platform. For the older Cisco IOS versions, the maximum-paths was 6. The latest version typically supports 16 or more.

 R1 (config)#router eigrp 100

R1 (config-router)#maximum-paths ?

  <1-32> Number of paths

Unequal cost load-balancing

EIGRP also supports unequal cost load balancing, it has to be done manually using variance. Variance is a multiplier value that ranges between ­(1 – 128) and the default is 1. The routes that can go for load balancing should satisfy the condition. The cost of the successor X variance > cost of the other routes to be used for load balancing

• ·         The variance is multiplied by the current Feasible Distance.
• ·         Any feasible successor whose calculated metric is less than or equal to the product of the variance and feasible distance is added to the IP routing table, assuming that the maximum-paths setting allows more routes
• ·         Routes that are neither successor nor feasible successor routes can never add to the IP routing table, regardless of the variance setting. 

Before we start  EIGRP configuration check out some important of EIGRP CCIE exam topics.

Here are the lists of all EIGRP labs and theories CCNA to CCIE

1.Enhanced Interior Gateway Routing Protocol (EIGRP)

2.Stuck In Active (EIGRP)

3.EIGRP Equal-Cost and Unequal-Cost load balancing

4.Route filtering passive interface

5.Route summarization

6.EIGRP STUB and Configuration

7.Routing Protocol Authentication (EIGRP ) and configuration

Configuration of EIGRP Equal cost load balancing-

Topology:

•      Configure the topology as per the diagram
•          Advertise the interfaces using EIGRP 100
•          Ensure the load balancing via traceroute.

R1#show ip interface  brief

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        10.1.1.1        YES manual up                    up

Serial3/0              1.1.1.1         YES manual up                    up

Serial3/3              4.4.4.2         YES manual up                    up

R2#show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        20.1.1.1        YES manual up                    up

FastEthernet1/0        unassigned      YES unset  administratively down down

FastEthernet1/1        unassigned      YES unset  administratively down down

GigabitEthernet2/0     unassigned      YES unset  administratively down down

Serial3/0              1.1.1.2         YES manual up                    up

Serial3/1              2.2.2.1         YES manual up                    up

R3#show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        30.1.1.1        YES manual up                    up

FastEthernet1/0        unassigned      YES unset  administratively down down

FastEthernet1/1        unassigned      YES unset  administratively down down

GigabitEthernet2/0     unassigned      YES unset  administratively down down

Serial3/0              unassigned      YES unset  administratively down down

Serial3/1              2.2.2.2         YES manual up                    up

Serial3/2              3.3.3.1         YES manual up                    up

R4#show ip interface brief

Interface              IP-Address      OK? Method Status                Protocol

FastEthernet0/0        40.1.1.1        YES manual up                    up

Serial3/2              3.3.3.2         YES manual up                    up

Serial3/3              4.4.4.1         YES manual up                    up

R1(config)#router eigrp 100

R1(config-router)#network 1.0.0.0

R1(config-router)#network 4.0.0.0

R1(config-router)#network 10.0.0.0

R1(config-router)#no auto-summary

R2(config)#router eigrp 100

R2(config-router)#network 20.0.0.0

R2(config-router)#network 1.0.0.0

R2(config-router)#network 2.0.0.0

R2(config-router)#no auto-summary

R3(config)#router eigrp 100

R3(config-router)#network 30.0.0.0

R3(config-router)#network 2.0.0.0

R3(config-router)#network 3.0.0.0

R3(config-router)#no auto-summary

R4(config)#router eigrp 100

R4(config-router)#network 4.0.0.0

R4(config-router)#network 3.0.0.0

R4(config-router)#network 40.0.0.0

R4(config-router)#no auto-summary

R1#show ip eigrp 100 neighbors

EIGRP-IPv4 Neighbors for AS(100)

H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq

                                                   (sec)         (ms)       Cnt Num

1   4.4.4.1                 Se3/3                    12 00:15:50   37   222  0  8

0   1.1.1.2                 Se3/0                    13 00:17:52   67   402  0  20

R3#show  ip eigrp neighbors

EIGRP-IPv4 Neighbors for AS(100)

H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq

                                                   (sec)         (ms)       Cnt Num

1   3.3.3.2                 Se3/2                    12 00:17:17   41   246  0  9

0   2.2.2.1                 Se3/1                    11 00:17:45   48   288  0  19

R1#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

D     2.0.0.0/8 [90/2681856] via 1.1.1.2, 00:17:19, Serial3/0

D     3.0.0.0/8 [90/2681856] via 4.4.4.1, 00:17:19, Serial3/3

D     20.0.0.0/8 [90/2172416] via 1.1.1.2, 00:17:19, Serial3/0

D     30.0.0.0/8 [90/2684416] via 4.4.4.1, 00:17:19, Serial3/3

                 [90/2684416] via 1.1.1.2, 00:17:19, Serial3/0

D     40.0.0.0/8 [90/2172416] via 4.4.4.1, 00:17:19, Serial3/3

The above output you can see that the router R1 installed both routes in the routing table as it is using both the routes to reach the network 30.1.1.1.

R1#show  ip eigrp topology

EIGRP-IPv4 Topology Table for AS(100)/ID(10.1.1.1)

Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,

       r - reply Status, s - sia Status

P 2.0.0.0/8, 1 successors, FD is 2681856

        via 1.1.1.2 (2681856/2169856), Serial3/0

P 4.0.0.0/8, 1 successors, FD is 2169856

        via Connected, Serial3/3

P 10.0.0.0/8, 1 successors, FD is 28160

        via Connected, FastEthernet0/0

P 30.0.0.0/8, 2 successors, FD is 2684416

        via 1.1.1.2 (2684416/2172416), Serial3/0

        via 4.4.4.1 (2684416/2172416), Serial3/3

P 3.0.0.0/8, 1 successors, FD is 2681856

        via 4.4.4.1 (2681856/2169856), Serial3/3

P 40.0.0.0/8, 1 successors, FD is 2172416

        via 4.4.4.1 (2172416/28160), Serial3/3

P 1.0.0.0/8, 1 successors, FD is 2169856

        via Connected, Serial3/0

P 20.0.0.0/8, 1 successors, FD is 2172416

        via 1.1.1.2 (2172416/28160), Serial3/0

R1#traceroute 30.1.1.1

Type escape sequence to abort.

Tracing the route to 30.1.1.1

VRF info: (vrf in name/id, vrf out name/id)

  1 1.1.1.2 76 msec

    4.4.4.1 112 msec

    1.1.1.2 52 msec

  2 3.3.3.1 100 msec

    2.2.2.2 68 msec

    3.3.3.1 48 msec

now R1 is doing equal cost load balancing vea R2 and R4 because both the routes are having equal cost to reach network 30.1.1.1

Route summarization

Route summarization

Route Summarization is the process of combining the contagious networks into one sub large network. Route summarization also called route aggregation, route summarization help to minimizing the routing table in an IP networks, summarization use less resources like memory, processor, and bandwidth.

Types of summarization:

1.       1.Auto summary

             Auto summarization is done to a default classful boundary

§  Class A       /8

§  Class B       /16

§  Class C       /24

             Routing protocol like RIPv2, EIGRP, and BGP v4 support               auto summarization and can be disable by the command                    R1(config-router)#no auto-summary

       

        2.Manual summary

        Administrator manually configure summarization to specific             boundary

         

       Manual summarization is supported by all classless routing               protocols like EIGRP, OSPF, RIPv2, and BGP.

 

 Steps for calculating manual summarization:      

Calculate the summary address formula you can use: 256 – number of networks = subnet mask for summary address.

Example: we want to create the most optimal summary for the following 4 networks:

192.168.0.0 / 24 subnet mask 255.255.255.0

192.168.1.0 / 24 subnet mask 255.255.255.0

192.168.2.0 / 24 subnet mask 255.255.255.0

192.168.3.0 / 24 subnet mask 255.255.255.0

 Convert these network addresses to binary:

192.168.0.0	11000000	10101000	00000000	00000000
192.168.1.0	11000000	10101000	00000001	00000000
192.168.2.0	11000000	10101000	00000010	00000000
192.168.3.0	11000000	10101000	00000011	00000000

Now we can see how many bits these network addresses have in common. The first and second octets are having the same, so that’s 16 bits.

Take a look in the third octet:

00000000

00000001

00000010

00000011

You see the first 6 bits of the third octet are the same. Now create our summary address. Calculate 8 + 8 + 6 = 22 bits

Our summary address will be 192.168.0.0 /22 (subnet mask 255.255.252.0).

Now we have seen how to do this in binary, now we do it in decimal. It is a simple trick you can use to calculate this summary.

As you see we have 4 networks, or it’s a block of 4.

 Here is a formula you can use:

256 - Number of networks = subnet mask for summary address.

For our example: 256 - 4 networks = 252

So the subnet mask will be 255.255.252.0

Another way to see at it is by using the CIDR notation. We know a /24 is a block of 256 addresses.  Using a /23 means we have 2 x 256, and a /22 means we have 4 x 256.

lets configure summarization in EIGRP

Topology 

goal:

configure EIGRP 100 on R1, R2, R3, and R4. Advertise the interface as per the diagram

configure manual summarization of above networks as per the calculation.

R1(config)#router eigrp 100

R1(config-router)#network 10.0.0.0

R1(config-router)#network 11.0.0.0

R1(config-router)#no auto-summary

R2(config)#router eigrp 100

R2(config-router)#network 20.0.0.0

R2(config-router)#network 10.0.0.0

R2(config-router)#network 10.0.0.0

.R2(config-router)#network 30.0.0.0

R2(config-router)#no auto-summary

R3(config)#router eigrp 100

R3(config-router)#network 13.0.0.0

R3(config-router)#network 30.0.0.0

R3(config-router)#no auto-summary

R4(config)#router eigrp 100

R4(config-router)#network 20.0.0.0

R4(config-router)#network 14.0.0.0

R4(config-router)#no auto-summary

R1#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

      12.0.0.0/24 is subnetted, 4 subnets

D        12.0.0.0 [90/2297856] via 10.1.1.2, 00:00:09, Serial3/0

D        12.0.1.0 [90/2297856] via 10.1.1.2, 00:00:09, Serial3/0

D        12.0.2.0 [90/2297856] via 10.1.1.2, 00:00:09, Serial3/0

D        12.0.3.0 [90/2297856] via 10.1.1.2, 00:00:09, Serial3/0

      13.0.0.0/24 is subnetted, 4 subnets

D        13.0.0.0 [90/2809856] via 10.1.1.2, 00:10:47, Serial3/0

D        13.0.1.0 [90/2809856] via 10.1.1.2, 00:10:47, Serial3/0

D        13.0.2.0 [90/2809856] via 10.1.1.2, 00:10:47, Serial3/0

D        13.0.3.0 [90/2809856] via 10.1.1.2, 00:10:47, Serial3/0

      14.0.0.0/24 is subnetted, 4 subnets

D        14.0.0.0 [90/2809856] via 10.1.1.2, 00:09:50, Serial3/0

D        14.0.1.0 [90/2809856] via 10.1.1.2, 00:09:50, Serial3/0

D        14.0.2.0 [90/2809856] via 10.1.1.2, 00:09:50, Serial3/0

D        14.0.3.0 [90/2809856] via 10.1.1.2, 00:09:50, Serial3/0

D     20.0.0.0/8 [90/2681856] via 10.1.1.2, 00:11:31, Serial3/0

D     30.0.0.0/8 [90/2681856] via 10.1.1.2, 00:11:24, Serial3/0

  

R2#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

      11.0.0.0/24 is subnetted, 4 subnets

D        11.0.0.0 [90/2297856] via 10.0.0.1, 00:12:32, Serial3/0

D        11.0.1.0 [90/2297856] via 10.0.0.1, 00:12:32, Serial3/0

D        11.0.2.0 [90/2297856] via 10.0.0.1, 00:12:32, Serial3/0

D        11.0.3.0 [90/2297856] via 10.0.0.1, 00:12:32, Serial3/0

      13.0.0.0/24 is subnetted, 4 subnets

D        13.0.0.0 [90/2297856] via 30.1.1.2, 00:11:48, Serial3/1

D        13.0.1.0 [90/2297856] via 30.1.1.2, 00:11:48, Serial3/1

D        13.0.2.0 [90/2297856] via 30.1.1.2, 00:11:48, Serial3/1

D        13.0.3.0 [90/2297856] via 30.1.1.2, 00:11:48, Serial3/1

      14.0.0.0/24 is subnetted, 4 subnets

D        14.0.0.0 [90/2297856] via 20.1.1.2, 00:10:51, Serial3/2

D        14.0.1.0 [90/2297856] via 20.1.1.2, 00:10:51, Serial3/2

D        14.0.2.0 [90/2297856] via 20.1.1.2, 00:10:51, Serial3/2

D        14.0.3.0 [90/2297856] via 20.1.1.2, 00:10:51, Serial3/2

R3#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

D     10.0.0.0/8 [90/2681856] via 30.1.1.1, 00:12:21, Serial3/1

      11.0.0.0/24 is subnetted, 4 subnets

D        11.0.0.0 [90/2809856] via 30.1.1.1, 00:12:21, Serial3/1

D        11.0.1.0 [90/2809856] via 30.1.1.1, 00:12:21, Serial3/1

D        11.0.2.0 [90/2809856] via 30.1.1.1, 00:12:21, Serial3/1

D        11.0.3.0 [90/2809856] via 30.1.1.1, 00:12:21, Serial3/1

      12.0.0.0/24 is subnetted, 4 subnets

D        12.0.0.0 [90/2297856] via 30.1.1.1, 00:01:42, Serial3/1

D        12.0.1.0 [90/2297856] via 30.1.1.1, 00:01:42, Serial3/1

D        12.0.2.0 [90/2297856] via 30.1.1.1, 00:01:42, Serial3/1

D        12.0.3.0 [90/2297856] via 30.1.1.1, 00:01:42, Serial3/1

      14.0.0.0/24 is subnetted, 4 subnets

D        14.0.0.0 [90/2809856] via 30.1.1.1, 00:11:23, Serial3/1

D        14.0.1.0 [90/2809856] via 30.1.1.1, 00:11:23, Serial3/1

D        14.0.2.0 [90/2809856] via 30.1.1.1, 00:11:23, Serial3/1

D        14.0.3.0 [90/2809856] via 30.1.1.1, 00:11:23, Serial3/1

D     20.0.0.0/8 [90/2681856] via 30.1.1.1, 00:12:21, Serial3/1

R4#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

D     10.0.0.0/8 [90/2681856] via 20.1.1.1, 00:12:03, Serial3/2

      11.0.0.0/24 is subnetted, 4 subnets

D        11.0.0.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        11.0.1.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        11.0.2.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        11.0.3.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

      12.0.0.0/24 is subnetted, 4 subnets

D        12.0.0.0 [90/2297856] via 20.1.1.1, 00:02:15, Serial3/2

D        12.0.1.0 [90/2297856] via 20.1.1.1, 00:02:15, Serial3/2

D        12.0.2.0 [90/2297856] via 20.1.1.1, 00:02:15, Serial3/2

D        12.0.3.0 [90/2297856] via 20.1.1.1, 00:02:15, Serial3/2

      13.0.0.0/24 is subnetted, 4 subnets

D        13.0.0.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        13.0.1.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        13.0.2.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D        13.0.3.0 [90/2809856] via 20.1.1.1, 00:12:03, Serial3/2

D     30.0.0.0/8 [90/2681856] via 20.1.1.1, 00:12:03, Serial3/2

R1(config)#interface serial 3/0

R1(config-if)#ip summary-address eigrp 100 11.0.0.0 255.255.252.0

R2(config)#interface serial 3/0

R2(config-if)#ip summary-address eigrp 100 12.0.0.0 255.255.252.0

R2(config-if)#interface serial 3/1
R2(config-if)#ip summary-address eigrp 100 12.0.0.0 255.255.252.0
R2(config-if)#interface serial 3/2
R2(config-if)#ip summary-address eigrp 100 12.0.0.0 255.255.252.0

R3(config)#interface serial 3/1

R3(config-if)#ip summary-address eigrp 100 13.0.0.0 255.255.252.0

R4(config)#interface serial 3/2

R4(config-if)#ip summary-address eigrp 100 14.0.0.0 255.255.252.0

R1#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

      11.0.0.0/8 is variably subnetted, 9 subnets, 3 masks

D        11.0.0.0/22 is a summary, 00:03:20, Null0

      12.0.0.0/22 is subnetted, 1 subnets

D        12.0.0.0 [90/2297856] via 10.1.1.2, 00:02:43, Serial3/0

      13.0.0.0/22 is subnetted, 1 subnets

D        13.0.0.0 [90/2809856] via 10.1.1.2, 00:01:41, Serial3/0

      14.0.0.0/22 is subnetted, 1 subnets

D        14.0.0.0 [90/2809856] via 10.1.1.2, 00:01:14, Serial3/0

D     20.0.0.0/8 [90/2681856] via 10.1.1.2, 00:19:14, Serial3/0

D     30.0.0.0/8 [90/2681856] via 10.1.1.2, 00:19:07, Serial3/0

R2#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

      11.0.0.0/22 is subnetted, 1 subnets

D        11.0.0.0 [90/2297856] via 10.0.0.1, 00:03:32, Serial3/0

      12.0.0.0/8 is variably subnetted, 9 subnets, 3 masks

D        12.0.0.0/22 is a summary, 00:02:55, Null0

      13.0.0.0/22 is subnetted, 1 subnets

D        13.0.0.0 [90/2297856] via 30.1.1.2, 00:01:53, Serial3/1

      14.0.0.0/22 is subnetted, 1 subnets

D        14.0.0.0 [90/2297856] via 20.1.1.2, 00:01:26, Serial3/2

R3#show ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

D     10.0.0.0/8 [90/2681856] via 30.1.1.1, 00:18:56, Serial3/1

      11.0.0.0/22 is subnetted, 1 subnets

D        11.0.0.0 [90/2809856] via 30.1.1.1, 00:03:45, Serial3/1

      12.0.0.0/22 is subnetted, 1 subnets

D        12.0.0.0 [90/2297856] via 30.1.1.1, 00:02:38, Serial3/1

      13.0.0.0/8 is variably subnetted, 9 subnets, 3 masks

D        13.0.0.0/22 is a summary, 00:02:07, Null0

      14.0.0.0/22 is subnetted, 1 subnets

D        14.0.0.0 [90/2809856] via 30.1.1.1, 00:01:39, Serial3/1

D     20.0.0.0/8 [90/2681856] via 30.1.1.1, 00:18:56, Serial3/1

R4#show  ip route eigrp

Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP

       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area

       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2

       E1 - OSPF external type 1, E2 - OSPF external type 2

       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2

       ia - IS-IS inter area, * - candidate default, U - per-user static route

       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP

       + - replicated route, % - next hop override

Gateway of last resort is not set

D     10.0.0.0/8 [90/2681856] via 20.1.1.1, 00:18:15, Serial3/2

      11.0.0.0/22 is subnetted, 1 subnets

D        11.0.0.0 [90/2809856] via 20.1.1.1, 00:03:55, Serial3/2

      12.0.0.0/22 is subnetted, 1 subnets

D        12.0.0.0 [90/2297856] via 20.1.1.1, 00:02:55, Serial3/2

      13.0.0.0/22 is subnetted, 1 subnets

D        13.0.0.0 [90/2809856] via 20.1.1.1, 00:02:16, Serial3/2

      14.0.0.0/8 is variably subnetted, 9 subnets, 3 masks

D        14.0.0.0/22 is a summary, 00:01:49, Null0

D     30.0.0.0/8 [90/2681856] via 20.1.1.1, 00:18:15, Serial3/2

 R1#ping 14.0.0.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 14.0.0.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 36/40/56 ms

R1#ping 13.0.0.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 13.0.0.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 28/60/76 ms

R1#ping 12.0.0.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 12.0.0.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 36/36/40 ms

 R4#traceroute 13.0.0.1

Type escape sequence to abort.

Tracing the route to 13.0.0.1

VRF info: (vrf in name/id, vrf out name/id)

  1 20.1.1.1 40 msec 68 msec 60 msec

  2 30.1.1.2 144 msec 144 msec 64 msec