annotations: [] smart_annotations: [] nodes: - boot_disk_size: null configuration: - name: ios_config.txt content: |- hostname R1 no ip domain-lookup line con 0 logging synchronous exec-timeout 0 0 ! interface Loopback0 ip address 1.1.1.1 255.255.255.255 no shutdown ! interface Ethernet0/0 description Link_to_R2_P2P ip address 10.0.12.1 255.255.255.252 no shutdown ! interface Ethernet0/1 description Link_to_R3_Broadcast ip address 10.0.13.1 255.255.255.0 no shutdown ! end cpu_limit: null cpus: null data_volume: null hide_links: false id: n0 image_definition: null label: R1 node_definition: iol-xe parameters: {} ram: null tags: [] x: 0 y: 0 interfaces: - id: i0 label: Loopback0 mac_address: null type: loopback - id: i1 label: Ethernet0/0 mac_address: null type: physical slot: 0 - id: i2 label: Ethernet0/1 mac_address: null type: physical slot: 1 - id: i3 label: Ethernet0/2 mac_address: null type: physical slot: 2 - id: i4 label: Ethernet0/3 mac_address: null type: physical slot: 3 - boot_disk_size: null configuration: - name: ios_config.txt content: |- hostname R2 no ip domain-lookup line con 0 logging synchronous exec-timeout 0 0 ! interface Loopback0 ip address 2.2.2.2 255.255.255.255 no shutdown ! interface Ethernet0/0 description Link_to_R1_P2P ip address 10.0.12.2 255.255.255.252 no shutdown ! end cpu_limit: null cpus: null data_volume: null hide_links: false id: n1 image_definition: null label: R2 node_definition: iol-xe parameters: {} ram: null tags: [] x: -320 y: 200 interfaces: - id: i0 label: Loopback0 mac_address: null type: loopback - id: i1 label: Ethernet0/0 mac_address: null type: physical slot: 0 - id: i2 label: Ethernet0/1 mac_address: null type: physical slot: 1 - id: i3 label: Ethernet0/2 mac_address: null type: physical slot: 2 - id: i4 label: Ethernet0/3 mac_address: null type: physical slot: 3 - boot_disk_size: null configuration: - name: ios_config.txt content: |- hostname R3 no ip domain-lookup line con 0 logging synchronous exec-timeout 0 0 ! interface Loopback0 ip address 3.3.3.3 255.255.255.255 no shutdown ! interface Ethernet0/0 description Link_to_R1_Broadcast ip address 10.0.13.3 255.255.255.0 no shutdown ! end cpu_limit: null cpus: null data_volume: null hide_links: false id: n2 image_definition: null label: R3 node_definition: iol-xe parameters: {} ram: null tags: [] x: 300 y: 200 interfaces: - id: i0 label: Loopback0 mac_address: null type: loopback - id: i1 label: Ethernet0/0 mac_address: null type: physical slot: 0 - id: i2 label: Ethernet0/1 mac_address: null type: physical slot: 1 - id: i3 label: Ethernet0/2 mac_address: null type: physical slot: 2 - id: i4 label: Ethernet0/3 mac_address: null type: physical slot: 3 links: - id: l0 n1: n0 n2: n1 i1: i1 i2: i1 conditioning: {} label: R1-Ethernet0/0<->R2-Ethernet0/0 - id: l1 n1: n0 n2: n2 i1: i2 i2: i1 conditioning: {} label: R1-Ethernet0/1<->R3-Ethernet0/0 lab: description: CCNA 200-301 practice lab covering OSPFv2 neighbor adjacencies, DR/BDR election, point-to-point links, and router IDs. notes: |- # OSPFv2 Single-Area Lab ## Objectives 1. Configure loopback interfaces as OSPF Router IDs on all routers. 2. Enable single-area OSPFv2 (Area 0) on all routers. 3. Observe and control DR/BDR election on the broadcast segment. 4. Verify point-to-point behavior (no DR/BDR) on the R1-R2 link. 5. Confirm full OSPF adjacency and routing table population. ## Topology Overview - **R1** — Hub router. Connects to R2 via `Ethernet0/0` (point-to-point) and to R3 via `Ethernet0/1` (broadcast segment). - **R2** — Connects to R1 via `Ethernet0/0` (point-to-point). - **R3** — Connects to R1 via `Ethernet0/0` (broadcast segment). ## IP Addressing Plan | Device | Interface | IP Address | |--------|-------------|---------------| | R1 | Loopback0 | 1.1.1.1/32 | | R1 | Ethernet0/0 | 10.0.12.1/30 | | R1 | Ethernet0/1 | 10.0.13.1/24 | | R2 | Loopback0 | 2.2.2.2/32 | | R2 | Ethernet0/0 | 10.0.12.2/30 | | R3 | Loopback0 | 3.3.3.3/32 | | R3 | Ethernet0/0 | 10.0.13.3/24 | ## Link Summary | Link | R1 Interface | Remote Interface | Segment | Type | |---------|-------------|------------------|---------------|----------------| | R1 - R2 | Ethernet0/0 | R2 Ethernet0/0 | 10.0.12.0/30 | Point-to-Point | | R1 - R3 | Ethernet0/1 | R3 Ethernet0/0 | 10.0.13.0/24 | Broadcast | ## Tasks ### Task 1 — Base Configuration (Pre-configured) The following have already been applied to all routers: - Hostnames: R1, R2, R3 - Loopback0 and physical interface IP addresses per the table above - `no ip domain-lookup` and console `logging synchronous` Verify with: `show ip interface brief` ### Task 2 — Enable OSPFv2 - Use process ID **1** on all routers. - Advertise all networks (loopbacks and physical) into **Area 0**. - Verify Router IDs are correctly derived from Loopback0 using `show ip ospf`. ### Task 3 — DR/BDR Election (Broadcast Segment: 10.0.13.0/24) - On R1 (`Ethernet0/1`) and R3 (`Ethernet0/0`), observe DR/BDR roles after enabling OSPF. - Use `show ip ospf neighbor` and `show ip ospf interface Ethernet0/1` on R1. - Manipulate OSPF **priority** to ensure **R1** is always the DR on this segment. > Hint: Default priority is 1. Higher wins. Priority 0 = ineligible. ### Task 4 — Point-to-Point Verification (10.0.12.0/30) - On the R1 (`Ethernet0/0`) — R2 (`Ethernet0/0`) link, confirm no DR/BDR election occurs. - Use `show ip ospf interface Ethernet0/0` on both R1 and R2. > Hint: What OSPF network type eliminates DR/BDR election? ### Task 5 — Verification - `show ip ospf neighbor` — confirm **FULL** state on all adjacencies. - `show ip route ospf` — confirm all OSPF-learned routes are present on each router. - `show ip ospf database` — explore the Link State Database (LSDB). ## Key Commands Reference | Purpose | Command | |---------------------------|-----------------------------------| | Enable OSPF | `router ospf 1` | | Advertise a network | `network area 0` | | Set Router ID | `router-id ` | | Set OSPF priority | `ip ospf priority <0-255>` | | Check neighbors | `show ip ospf neighbor` | | Check interface OSPF info | `show ip ospf interface ` | | Check routing table | `show ip route ospf` | | View LSDB | `show ip ospf database` | title: CCNA OSPFv2 Single-Area Lab version: 0.3.0