Free CCNA | Static Routing | Day 11 (part 2) | CCNA 200-301 Complete Course

Name: Free CCNA | Static Routing | Day 11 (part 2) | CCNA 200-301 Complete Course
Uploaded: 2022-12-27T11:00:29.000Z
Duration: 1 h 14 min 44 s

Welcome to Jeremy’s IT Lab

This video is a complete course for the CCNA exam, focusing on static routing. It covers the basics of routing, including local and connected routes. Static routes are introduced as a way to send packets to remote destinations.

Review of Connected and Local Routes

Connected and local routes are automatically added to a router's routing table when an IP address is configured on an interface.

These routes provide access to the router's own IP address and the network the interface is connected to.

Introduction to Static Routes

Static routes allow routers to send packets to remote destinations that are not directly connected.

Configuration of static routes in Cisco routers will be covered in this video.

Manual Configuration of Static Routes

Unlike connected and local routes, static routes must be manually configured and are not automatically added to the routing table.

Understanding Default Routes

The concept of default routes will also be explained in this video.

Reviewing Connected and Local Routes

This section reviews connected and local routes by configuring IP addresses on routers and checking their routing tables.

R2 Routing Table

R2 has two connected routes: one for 192.168.12.0/24 and one for 24.0/24.

It also has two local routes: one for 192.168.12.2/32 and one for 24.2/32.

R2 knows how to reach its own IP addresses and destinations in its connected networks but doesn't know how to reach other networks in the topology.

R3 Routing Table

R3 has two connected routes: one for 192.168.13.0/24 and one for 34.0/24.

It also has two local routes: one for 192.168.13.3/32 and one for 34.3/32.

R3 knows how to reach its own IP addresses and destinations in its connected networks but doesn't know how to reach other networks.

R4 Routing Table

R4 has three connected routes and three local routes.

It knows how to reach its own IP addresses and destinations in its connected networks but not remote networks.

Configuring Routes for Communication

This section discusses configuring routers to allow communication between PC1 and PC4.

Configuring Routes

The routers need additional configuration to enable communication between PC1 and PC4.

Connected and local routes alone are not sufficient for this purpose.

Summary of Router Knowledge

All routers have connected and local routes, allowing them to reach their own IP addresses and destinations in their connected networks.

However, they do not know how to reach destinations in remote networks.

Conclusion

The conclusion of the video summarizes the routing tables of each router and emphasizes the need for additional configuration to enable communication between PCs in different networks.

Routing Tables Recap

Each router has connected and local routes that provide access to its own IP addresses and destinations in its connected networks.

However, routers do not have routes for reaching destinations in remote networks by default.

Need for Additional Configuration

To enable communication between PCs in different networks, additional configuration is required on the routers.

The transcript provided does not include specific timestamps beyond the initial ones mentioned at the beginning of each section.

New Section

This section explains the concept of default gateway and its role in communication between hosts in different networks.

Default Gateway Configuration

PC1 is connected to 192.168.1.0/24 network and PC4 is connected to 4.0/24 network.

To communicate with destinations outside their local network, both PCs need to send packets to their default gateway (or default router).

The default gateway configuration specifies the IP address of the router that will handle packets destined for other networks.

In Linux, interface configurations are stored in a text file that can be edited.

PC1's configuration includes an IP address of 192.168.1.10/24 and a default gateway of 192.168.1.1.

PC4's configuration includes an IP address of 4.x.x.x/24 and a default gateway specific to its network.

New Section

This section discusses the concept of a default route and its significance in routing packets outside the local network.

Understanding Default Route

A default route is also known as a "default gateway" or "gateway of last resort".

It is a route to the destination network 0.0.0.0/0, which includes all IP addresses.

The default route is considered the least specific route because it covers all possible IP addresses.

It allows end hosts like PC1 and PC4 to send packets outside their local network by forwarding them to the configured default gateway/router.

The range covered by 0.0.0.0/0 includes over 4 billion IP addresses.

New Section

This section compares the least specific (default) route with the most specific (local) route and explains their significance in routing.

Comparing Default and Local Routes

A /32 route, such as a local route, is the most specific route as it specifies only one IP address.

For example, 192.168.1.1/32 specifies only the IP address 192.168.1.1.

The default route (0.0.0.0/0) is the least specific route as it includes all IP addresses.

When a packet doesn't match any more specific routes, the default route ensures that it is not dropped but forwarded via this route instead.

End hosts like PC1 and PC4 usually don't require more specific routes and rely on their default gateway to send packets outside their local network.

New Section

This section explains how end hosts determine the source and destination MAC addresses in Ethernet headers when sending packets to destinations outside their local network.

Source and Destination MAC Addresses

When PC1 wants to send a packet to PC4, its source IP address in the IP header is 192.168.1.10 (PC1's IP), and the destination IP is 4.x.x.x (PC4's IP).

The source and destination MAC addresses in the Ethernet header depend on Layer 2 and Layer 3 communication.

At Layer 3, PC1 wants to send the packet to PC4's IP (192.168.4.x), but it needs to forward it first to its default gateway/router (R1).

To encapsulate the packet into an Ethernet frame, PC1 sets R1 G0/2's MAC address as the destination MAC address.

New Section

This section briefly mentions ARP requests for learning MAC addresses but focuses on explaining how routers handle incoming packets.

Router Handling of Incoming Packets

PC1 sends the frame with R1 G0/2's MAC address as the destination to its default gateway (R1).

Upon receiving the frame, R1 de-encapsulates it by removing the Layer 2 header and trailer.

R1 then examines the inside packet and checks its routing table for a matching route.

If there is no matching route in R1's routing table, it has no choice but to drop the packet as it doesn't know how to forward it.

New Section

This section emphasizes the need for routers to have specific routes in their routing tables to properly forward packets.

Need for Specific Routes

To forward a packet, R1 needs a route to the destination network (192.168.4.0/24).

Routes are instructions that guide routers on how to handle packets.

Each router in the path from PC1 to PC4 requires two routes: one for PC1's network (192.168.1.0/24) and one for PC4's network (4.x.x.x/24).

These routes ensure two-way reachability between PC1 and PC4.

New Section

This section discusses multiple paths available between PC1 and PC4 and introduces the concept of load balancing.

Multiple Paths and Load Balancing

There are two possible paths from PC1 to PC4: one via R3 and another via R2.

In this video, we focus on using the path via R3.

Multiple paths allow routers to choose different routes based on various factors like load balancing or redundancy.

Load balancing distributes traffic across multiple paths, while redundancy provides backup paths in case of failures.

New Section

This section clarifies the usage of path 1 (via R3) and introduces the possibility of configuring routers to load balance or use different paths.

Path Selection and Configuration

In this video, we only consider using path 1, which is via R3.

The inclusion of R2 in the diagram demonstrates that routers can be configured to choose specific paths when multiple options exist.

Load balancing allows routers to distribute traffic between different paths, while backup paths provide redundancy.

Advanced techniques for path selection and configuration will be covered later in the course.

New Section

This section highlights the need for specific routes on each router along the path from PC1 to PC4.

Ensuring Communication Between PC1 and PC4

To enable communication between PC1 and PC4, not only does R1 require additional routes, but every router along the path needs routes for both networks (PC1's network and PC4's network).

This ensures two-way reachability so that packets can flow in both directions.

Understanding Routes and Next-Hop IP Addresses

In this section, the instructor explains that routers do not need routes to all networks in the path to the destination. They only need to know the next-hop IP address for each network. The example given is that R1 does not need a route to 192.168.34.0/24; it just needs to know that packets destined for 4.0/24 should be sent to R3.

Routers don't need routes to all networks in the path.

R1 doesn't need a route to 192.168.34.0/24; it just needs to know the next-hop IP address for 4.0/24.

R4 doesn't need a route to 192.168.13.0/24; it just needs to know the next-hop IP address for 1.0/24.

Planning Static Routes

Before configuring static routes, it is important to plan out which routes are needed for communication between PC1 and PC4.

Chart of routes needed by R1, R3, and R4 for PC1 and PC4 communication.

Blue indicates connected routes (next-hop is "connected").

Red indicates static routes that need configuration.

Determining Next-Hop IP Addresses

The instructor asks viewers to pause the video and think about what the correct next-hop IP addresses should be for each route before revealing the answers.

For R1's packet destined for 4.0/24 network, the correct next-hop IP address is 192.168.13.3 (R3's G0/0 interface).

For R3's packet destined for 192.168.1.0/24 network, the correct next-hop IP address is 192.168.13.1 (R1's G0/0 interface).

For R3's packet destined for 4.0/24 network, the correct next-hop IP address is 192.168.34.4 (R4's G0/1 interface).

For R4's packet destined for 1.0/24 network, the correct next-hop IP address is 192.168.34.3 (R3's G0/1 interface).

Configuring Static Routes

The instructor explains how to configure static routes on R1, R3, and R4 to enable communication between PC1 and PC4.

Format of the command to configure a static route: IP ROUTE <destination network IP> <netmask> <next-hop IP>.

Example configuration of R1's route to the 4.0/24 network: IP ROUTE 192.168.4.0 255.255.255.0 192.168.13.

Checking R1's routing table shows the static route highlighted with code "S" and its corresponding entry in the table.

Explanation of administrative distance and metric numbers in square brackets.

Configuration on R3

The instructor explains that R3 needs two routes configured - one for the 192..168..1..0/24 network and one for the 4..0..24 network.

Configuration of R3's route to the 192..168..1..0/24 network with next hop as R1.

Configuration of R3's route to the 4..0..24 network with next hop as R4.

Checking R3's routing table shows both routes with their respective next-hop IP addresses.

Configuration on R4

The instructor explains how to configure R4's route to the 192.168.1.0/24 network.

Configuration of R4's route to the 192.168.1.0/24 network with next hop as R3.

Checking R4's routing table shows the newly configured static route.

Testing Communication between PC1 and PC4

The instructor tests if PC1 and PC4 can communicate by pinging from PC1 to PC4.

Successful ping test indicates two-way reachability between PC1 and PC4.

Ping statistics show 5 packets transmitted, 5 packets received, and 0% packet loss.

Preview of Packet Encapsulation Process

The instructor briefly explains how a packet from PC1 to PC4 is encapsulated, de-encapsulated, and re-encapsulated in different frames as it travels through the network.

Layer 3 destination for a message from PC1 to PC4 is PC4's IP address (192.168.4.10).

Layer 2 destination for the frame is R1's G0/2 interface (PC1's default gateway).

Explanation that R1 encapsulates the packet in a new Ethernet frame with the destination MAC address of the next-hop (R3).

Timestamps are provided for each section based on the transcript provided by the user

New Section

This section explains the process of forwarding packets and introduces an option for configuring static routes.

Forwarding Packets and Destination MAC Address

When forwarding a packet to PC4, the router encapsulates the packet in a frame with PC4's MAC as the destination.

The destination IP and MAC addresses are both PC4's IP and MAC.

Understanding this process is important but will be covered step-by-step in another video.

Configuring Static Routes with Exit Interface

Instead of specifying a next-hop, static routes can be configured with an 'exit-interface'.

This means that the router sends packets out of a specific interface rather than specifying the actual IP address of the next hop.

For example, if R2 wants to send packets to the 192.168.1.0/24 network, it should send them out of G0/0 interface connected to R1.

The command for this configuration is IP ROUTE 192.168.1.0 255.255.255.0 G0/0.

Configuring Static Routes with Exit Interface and Next Hop

It is also possible to specify both the exit interface and the next hop when configuring static routes.

For example, if R2 wants to send packets to the 192.168.4.0/24 network, it should send them out of G0/1 interface connected to R4.

The next-hop IP address in this case would be 192.168.24.4, which is R4's G0/0 interface.

The command for this configuration is IP ROUTE 192.168.4.0 255.255.255.0 G0/1 192.168.24.4.

Proxy ARP and Static Routes

When configuring static routes with only the exit interface, the routing table displays the destination network as 'directly connected'.

This relies on a feature called 'proxy ARP' to function.

It is recommended to specify either the next-hop or both exit-interface and next-hop when configuring static routes.

Proxy ARP is beyond the scope of CCNA.

New Section

This section covers default routes and their usage in directing traffic.

Default Routes Explained

A default route is a route to 0.0.0.0/0, which includes every possible destination IP address.

If a router doesn't have any more specific routes for a packet's destination IP address, it will forward the packet using the default route.

Default routes are commonly used to direct traffic to the Internet.

Configuring Default Route on Cisco Router

To configure a default route on a Cisco router, use the command IP ROUTE 0.0.0.0 0.0.0.0 <next-hop>.

The network and netmask should both be all 0s (0.0.0.0).

The next-hop represents where all other traffic should be sent.

Checking Routing Table for Default Route

In R1's routing table, if no default route has been configured yet, it will show "Gateway of last resort is not set".

After configuring a default route, check R1's routing table to verify its presence.

The default route will be displayed as "route: 0.0.0. via <next-hop>" with an asterisk indicating it as a candidate default.

New Section

This section concludes the discussion on default routes and their usage.

Default Routes for Internet Traffic

Default routes are commonly used to direct traffic to destinations outside of the internal network, such as the Internet.

More specific routes are used for destinations within the internal corporate network.

The example scenario shows R1 connected to R2 and R3, with more specific routes for internal networks and a default route for Internet traffic.

Summary of Default Route Configuration

Configuring a default route involves using the command IP ROUTE 0.0.0.0 0.0.0.0 <next-hop>.

The default route directs all other traffic to the specified next-hop.

Multiple candidates can exist for a default route, but only one will be selected as the router's default gateway.

The transcript is in English, so the notes are also provided in English.

New Section

In this section, the speaker discusses static routes, enabling communication between PC1 and PC4, configuring static routes, default routes, and a quiz to test understanding.

Static Routes and Enabling Communication

Static routes are discussed as a means to enable communication between PC1 and PC4 over the network.

The speaker lists the commands used to configure static routes.

Different options for configuring static routes are mentioned.

Default routes are briefly revisited in relation to PC1 and PC4's default gateways.

Configuration of a default route on a Cisco router is explained.

Quiz Question 1 - Configuring Default Route

The first quiz question asks about the command used to configure a default route on a Cisco router.

The correct answer is A - IP ROUTE 0.0.0.0 0.0.0.0 10.1.1.255.

Explanation is provided regarding the format of specifying next-hop IP address and netmask in static route configuration.

Quiz Question 2 - Forwarding Packets

The second quiz question asks which interface R1 will use to forward packets destined for 8.8.8.8.

The correct answer is C - gigabitethernet0/2, as it matches the default route with next hop 203.0.113.2.

Graphing Static Routes for Communication

A network diagram is presented for graphing the static routes needed for communication between PC1 and PC4.

Each router in the path requires specific routes to be configured for both destination networks (192.168.1.0/24 and 4.0/24).

The necessary routes for R1, R2, and R4 are explained.

Quiz Question 4 - Configuring Static Route

The fourth quiz question asks about the command used to configure a specific static route in R1's routing table.

The correct answer is D - IP ROUTE 172.20.0.0 255.255.0.0 g0/1.

Explanation is provided regarding the code 'S' indicating a static route and the inability to configure a network address on an interface.

Understanding Static Routes on R3

A diagram is shown to determine the number of static routes required for R3 to know all destination networks.

Four additional routes need to be configured on R3 for it to know all destination networks in the diagram.

Timestamps have been associated with relevant bullet points as requested.