> For the complete documentation index, see [llms.txt](https://netsec.nerd-cafe.ir/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://netsec.nerd-cafe.ir/network-engineering/ccna/configuring-eigrp.md).

# Configuring EIGRP

### <mark style="color:blue;">Topology</mark>

<figure><img src="/files/CZgSVsgOdAaROTI4T5QA" alt=""><figcaption><p>Topology</p></figcaption></figure>

#### **Understanding the Topology**

The provided network consists of **three routers (R1, R2, R3)** connected using **serial links** and **local area networks (LANs) for PCs**:

* **R1:**
  * Fa0/0: **192.168.0.1/24** → Connected to **PC0 (192.168.0.100)**
  * Fa1/0: **192.168.1.1/24** → Connected to **PC1 (192.168.1.100)**
  * S3/0: **10.0.0.1/30** → Connected to **R2 (10.0.0.2)**
* **R2:**
  * Fa0/0: **192.168.2.1/24** → Connected to **PC2 (192.168.2.100)**
  * Fa1/0: **192.168.3.1/24** → Connected to **PC3 (192.168.3.100)**
  * S3/0: **10.0.0.2/30** → Connected to **R1 (10.0.0.1)**
  * S3/1: **10.0.1.1/30** → Connected to **R3 (10.0.1.2)**
* **R3:**
  * Fa0/0: **192.168.4.1/24** → Connected to **PC4 (192.168.4.100)**
  * Fa1/0: **192.168.5.1/24** → Connected to **PC5 (192.168.5.100)**
  * S3/1: **10.0.1.2/30** → Connected to **R2 (10.0.1.1)**

### <mark style="color:blue;">**Step 1: Configure IP Addresses**</mark>

#### **R1 Configuration**

```
R1#configure terminal
R1(config)#interface fastEthernet 0/0
R1(config-if)#ip address 192.168.0.1 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface fastEthernet 1/0
R1(config-if)#ip address 192.168.1.1 255.255.255.0
R1(config-if)#no shutdown
R1(config-if)#exit
R1(config)#interface serial 3/0
R1(config-if)#ip address 10.0.0.1 255.255.255.252
R1(config-if)#clock rate 64000
R1(config-if)#no shutdown
```

#### R2 Configuration

```
R2#configure terminal
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 192.168.2.1 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface fastEthernet 1/0
R2(config-if)#ip address 192.168.3.1 255.255.255.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface serial 3/0
R2(config-if)#ip address 10.0.0.2 255.255.255.252
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#interface serial 3/1
R2(config-if)#ip address 10.0.1.1 255.255.255.252
R2(config-if)#clock rate 64000
R2(config-if)#no shutdown
```

#### R3 Configuration

```
R3#configure terminal
R3(config)#interface fastEthernet 0/0
R3(config-if)#ip address 192.168.4.1 255.255.255.0
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface fastEthernet 1/0
R3(config-if)#ip address 192.168.5.1 255.255.255.0
R3(config-if)#no shutdown
R3(config-if)#exit
R3(config)#interface serial 3/1
R3(config-if)#ip address 10.0.1.2 255.255.255.252
R3(config-if)#no shutdown
```

### <mark style="color:blue;">**Step 2: Configure EIGRP on All Routers**</mark>

**R1 - EIGRP Configuration**

```
/R1(config)#router eigrp 100
R1(config-router)#network 192.168.0.0 0.0.0.255
R1(config-router)#network 192.168.1.0 0.0.0.255
R1(config-router)#network 10.0.0.0 0.0.0.3
R1(config-router)#no auto-summary
```

#### R2 - EIGRP Configuration

```
R2(config)#router eigrp 100
R2(config-router)#network 192.168.2.0 0.0.0.255
R2(config-router)#network 192.168.3.0 0.0.0.255
R2(config-router)#network 10.0.0.0 0.0.0.3
R2(config-router)#network 10.0.1.0 0.0.0.3
R2(config-router)#no auto-summary
```

**R3 - EIGRP Configuration**

```
R3(config)#router eigrp 100
R3(config-router)#network 192.168.4.0 0.0.0.255
R3(config-router)#network 192.168.5.0 0.0.0.255
R3(config-router)#network 10.0.1.0 0.0.0.3
R3(config-router)#no auto-summary
```

### <mark style="color:blue;">**Step 3: Verify EIGRP**</mark>

Run the following command on all routers to verify neighbor relationships:

```
R2#show ip eigrp neighbors
EIGRP-IPv4 Neighbors for AS(100)
H   Address                 Interface              Hold Uptime   SRTT   RTO  Q  Seq
                                                   (sec)         (ms)       Cnt Num
1   10.0.1.2                Se3/1                    13 00:04:23 1287  5000  0  3
0   10.0.0.1                Se3/0                    14 00:06:12   46   276  0  5
R2#
```

Check the routing table to see if all routes are learned:

```
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

D     192.168.0.0/24 [90/2172416] via 10.0.0.1, 00:06:58, Serial3/0
D     192.168.1.0/24 [90/2172416] via 10.0.0.1, 00:06:58, Serial3/0
D     192.168.4.0/24 [90/2172416] via 10.0.1.2, 00:05:07, Serial3/1
D     192.168.5.0/24 [90/2172416] via 10.0.1.2, 00:05:07, Serial3/1
R2#
```

Ping from **PC0 (192.168.0.100)** to **PC1,2,3,4,5** to verify end-to-end connectivity:

```
PC0> ping 192.168.1.100

84 bytes from 192.168.1.100 icmp_seq=1 ttl=63 time=31.126 ms
84 bytes from 192.168.1.100 icmp_seq=2 ttl=63 time=15.068 ms
^C
PC0> ping 192.168.2.100

84 bytes from 192.168.2.100 icmp_seq=1 ttl=62 time=59.073 ms
84 bytes from 192.168.2.100 icmp_seq=2 ttl=62 time=34.183 ms
^C
PC0> ping 192.168.3.100

84 bytes from 192.168.3.100 icmp_seq=1 ttl=62 time=52.719 ms
84 bytes from 192.168.3.100 icmp_seq=2 ttl=62 time=40.976 ms
^C
PC0> ping 192.168.4.100

84 bytes from 192.168.4.100 icmp_seq=1 ttl=61 time=59.526 ms
84 bytes from 192.168.4.100 icmp_seq=2 ttl=61 time=44.194 ms
^C
PC0> ping 192.168.5.100

84 bytes from 192.168.5.100 icmp_seq=1 ttl=61 time=58.187 ms
84 bytes from 192.168.5.100 icmp_seq=2 ttl=61 time=53.073 ms
^C
PC0>
```

### <mark style="color:blue;">Keywords</mark>

`EIGRP`, `route summarization`, `Cisco`, `router configuration`, `IP addressing`, `subnetting`, `network topology`, `FastEthernet`, `Serial interface`, `routing protocol`, `neighbor adjacency`, `routing table`, `show commands`, `ping test`, `network efficiency`, `auto-summary`, `summary address`, `Packet Tracer`, `CCNA`, `network optimization`, سیسکو
