Static Routes
Sections:
Use Case Scenarios:
- Configuration of backup routes in conjunction with dynamic routing protocols as the primary route
- To achieve this scenario we will discuss Administrative Distance and Floating Static Routes in the Dynamic Routing Protocol section
- Configuration of default gateway of last resort
- Used to route traffic destined for any network not explicitly listed in the routing table
- Route Entry: (0.0.0.0/0)
Overview:
- Static Routes are manually configured routing entries in a router's routing table that specify how to reach a specific network or destination
- Static Routes are typically implemented when there is a need for a fixed, predictable path for traffic to travel
- In a later section we will analyze dynamic routing protocols as its a more scalable solution when multiple networks are at play
- In this lab scenario, we will define the static routes on R1, R2, and R3 respectively
Lab Topology
Looking at the topology, routers R2 and R3 will need 3 static routes configured whereas R1 will only need 2 static routes configured to have full reachability to all networks that are not directly connected.
Configuration
Static Routes: R1
Notes:
- From R1, we have defined 2 static routes towards the following networks that are not directly connected:
- Network between R2 and R3: 208.23.0.0/24
- Network off of R3: 10.3.3.0/24
- Command Syntax
- ip route <destination network> <destination subnet mask> <next-hop router>
- From the 'show ip route static' command, you can view all of the defined static routes
Static Routes: R2
Static Routes: R3
Reachability
Scenario: In this scenario, we will test out full reachability between hosts PC1 and PC3 using ICMP ping. With static routes configured on all 3 routers, each router will have all destination network entries in their routing table.
Notes:
- In this scenario, I have configured static IP addresses on the simulated PCs in the GNS3 environment in their respective networks
- I successfully am able to ping PC3 from PC1 by issuing the 'ping' command
- To verify the path of the ping packet, you can issue the traceroute command with the destination IP address
- In this case, the path the packet took was through R1 > R2 > R3 > PC3
