EX188 Networking And Compose Practice Test 4 — 15 Questions

Question 1

An operator wants to create a custom user-defined bridge network named 'app-net' with a specific subnet of '192.168.100.0/24' using Podman. Which command is correct?

Accepted Answer

podman network create --subnet 192.168.100.0/24 app-net. 'podman network create --subnet 192.168.100.0/24 app-net' is the correct syntax: the '--subnet' flag specifies the CIDR, and the network name follows as the positional argument. This creates a user-defined bridge network with the specified subnet.

Answer

podman bridge create app-net --subnet 192.168.100.0/24

Answer

podman create network --ip 192.168.100.0/24 app-net

Answer

podman network new --subnet=192.168.100.0/24 app-net

Question 2

Two containers running on the same custom user-defined bridge network need to communicate with each other. What built-in mechanism allows them to resolve each other by container name?

Accepted Answer

Automatic DNS resolution provided by the CNI/Netavark network backend. When containers are attached to the same user-defined bridge network in Podman, the Netavark (or CNI) network backend runs an embedded DNS resolver that registers each container's name and aliases. This allows containers to resolve each other by name without any manual configuration, similar to Docker's user-defined bridge behavior. The default bridge network does not provide this; only custom user-defined networks do.

Answer

Static ARP table broadcasting managed by the kernel

Answer

Multicast DNS (mDNS) running inside every container image by default

Answer

Automatic editing of the host's /etc/hosts file by the Podman daemon

Question 3

An administrator needs to inspect the configuration details, including subnet and gateway, of an existing custom network named 'my-net'. Which command should be executed?

Accepted Answer

podman network inspect my-net. The correct command is 'podman network inspect my-net'. The 'inspect' subcommand returns detailed JSON output about the network, including subnet, gateway, and connected containers. It is the standard way to view network configuration.

Answer

podman network show my-net

Answer

podman network details my-net

Answer

podman inspect network my-net

Question 4

You are deploying a container and want to bind its published port exclusively to the loopback interface (127.0.0.1) on the host to prevent external network access. Which syntax is correct?

Accepted Answer

-p 127.0.0.1:8080:80. The -p flag accepts an optional host IP prefix in the form [hostIP:]hostPort:containerPort. Specifying 127.0.0.1:8080:80 binds the published port only to the loopback interface, so only processes on the host itself can reach the container's port 80 via host port 8080. This is the standard Docker/Podman port-publishing syntax and is the only option that places the IP in the correct position.

Answer

-p 8080:80@127.0.0.1

Answer

-p 80:80 --host-ip 127.0.0.1

Answer

--bind-ip 127.0.0.1 -p 8080:80

Question 5

An administrator needs to connect an already running container named 'web1' to an existing user-defined network named 'backend-net' without restarting the container. Which command accomplishes this?

Accepted Answer

podman network connect backend-net web1. The podman network connect command attaches a running container to an existing user-defined network without requiring a restart. Its syntax is 'podman network connect ', which matches option B. This is the supported way to add a live container to an additional network, and Podman updates the container's DNS and interfaces dynamically.

Answer

podman network attach backend-net web1

Answer

podman container modify --network backend-net web1

Answer

podman network join --container web1 backend-net

Question 6

You have a Kubernetes YAML manifest file named 'app.yaml' that defines a Pod with network settings. You want to deploy this directly as a Podman container/pod on your local system. Which command should you use?

Accepted Answer

podman play kube app.yaml. 'podman play kube' reads a Kubernetes YAML manifest and creates the corresponding Podman pods and containers locally. It supports Pod, Deployment, and ConfigMap kinds, translating Kubernetes constructs into Podman equivalents. This is the correct command to deploy a Kubernetes manifest directly with Podman.

Answer

podman-compose up --file app.yaml

Answer

podman run --kube app.yaml

Answer

podman apply -f app.yaml

Question 7

When utilizing Podman Compose, how are service dependencies and container startup orders typically managed within the YAML structure?

Accepted Answer

Using the 'depends_on' configuration key under the service definition. Podman Compose, like Docker Compose, uses the 'depends_on' key under a service definition to express startup dependencies. This ensures that when a service is started, its dependencies are started first, controlling the order in which containers are launched. The 'depends_on' key does not wait for the dependent service to be 'ready' (e.g., healthy), only that it has been started, unless combined with health checks and conditions in some versions.

Answer

By ordering the service keys alphabetically in the YAML file

Answer

Using the 'links' parameter exclusively

Answer

Through the 'startup_order' directive

Question 8

Which configuration block in a Podman Compose YAML file is used to define custom isolated networks for the multi-container application?

Accepted Answer

networks:. In a Podman Compose YAML file, the top-level 'networks:' block defines custom isolated networks for the multi-container application. Services then reference these networks via their own 'networks:' key to attach to them.

Answer

interfaces:

Answer

bridges:

Answer

connections:

Question 9

An operator runs a Podman container and needs to inspect its assigned IP address directly from the container's runtime inspection output. Which command filters the JSON output to show only the IP address?

Accepted Answer

podman inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name. Podman stores container runtime metadata in a JSON structure accessible via 'podman inspect'. The Go template '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' iterates over the Networks map and prints only the IPAddress field, which is exactly the filtering behavior required. This avoids dumping the full JSON and isolates the assigned IP.

Answer

podman show-ip container_name

Answer

podman network ip container_name

Answer

podman inspect --ip container_name

Question 10

You need to completely remove a custom user-defined bridge network named 'test-net' that has no active containers attached to it. Which command performs this action?

Accepted Answer

podman network rm test-net. 'podman network rm test-net' removes the specified user-defined network. Since the network has no active containers attached, the removal succeeds immediately; if containers were attached, Podman would refuse unless forced. This is the direct, correct command for deleting a named network.

Answer

podman network prune --force

Answer

podman rm network test-net

Answer

podman network delete test-net

Question 11

When configuring container networking in Podman, which TWO built-in network modes are available by default without creating custom networks? (Choose two)

Accepted Answer

bridge. Option A (bridge) is correct because Podman ships with a default bridge network (named 'podman') that containers attach to by default, providing NAT-based connectivity and inter-container communication on the host. Option B (host) is correct because Podman supports the host network mode out of the box, where the container shares the host's network namespace and uses the host's IP stack directly. Options C (macvlan), D (routed), and E (overlay) are not default built-in modes: macvlan and overlay typically require creating a custom network with specific drivers, and routed is not a standard Podman network mode available without additional configuration.

Answer

macvlan

Answer

routed

Answer

overlay

Question 12

Which TWO statements are true regarding user-defined bridge networks in Podman? (Choose two)

Accepted Answer

They allow administrators to specify custom subnets and gateways during creation.. Option D is correct because when creating a user-defined bridge network with `podman network create`, administrators can pass flags such as `--subnet` and `--gateway` to define custom CIDR ranges and gateway addresses instead of relying on Podman's default allocations. Option E is correct because Podman runs an internal DNS server (aardvark-dns) on user-defined networks, allowing containers to resolve each other by container name or network alias rather than by IP address. Option A is wrong because user-defined bridge networks rely on normal netfilter/NAT rules and do not require disabling the host firewall. Option B is wrong because containers on separate user-defined bridge networks are isolated by default and cannot communicate without explicit routing or connecting a container to both networks. Option C is wrong because user-defined bridge networks still provide outbound connectivity to the internet via NAT/masquerading on the host.

Answer

They require the host firewall to be completely disabled to function.

Answer

Containers attached to different user-defined networks can communicate without explicit routing.

Answer

They prevent containers from communicating with the outside internet entirely.

Question 13

When working with Podman Compose files, which TWO options are valid keys that can be specified under a service definition for port and networking configuration? (Choose two)

Accepted Answer

networks. Option B (networks) is correct because in a Compose service definition, the networks key attaches the service's containers to one or more named networks declared in the top-level networks section, controlling inter-service connectivity and DNS resolution. Option D (ports) is correct because the ports key publishes container ports to the host using mappings such as "8080:80", which is the standard Compose mechanism for exposing service ports. Option A (firewall) is not a valid Compose service key; firewall rules are handled by the host or container runtime, not by Compose file syntax. Option C (nat_mapping) is not a Compose key; NAT behavior is implicit in port publishing rather than configured via a nat_mapping field. Option E (ip_address) is not a valid service-level key in Compose files; static IPs are set under a network's ipv4_address within the service's networks configuration, not as a top-level service key.

Answer

firewall

Answer

nat_mapping

Answer

ip_address

Question 14

Which THREE commands are valid Podman subcommands for managing container networks? (Choose three)

Accepted Answer

podman network ls. Option A, 'podman network ls', is correct because it is the standard Podman subcommand that lists all configured container networks (equivalent to 'podman network list'), showing network names, IDs, drivers, and interfaces. Option B, 'podman network create', is correct because it creates a new container network, allowing options such as --driver, --subnet, and --gateway to define CNI or Netavark network configuration. Option E, 'podman network inspect', is correct because it outputs detailed JSON metadata about one or more named networks, including subnets, gateways, and connected containers. Options C and D are not valid Podman subcommands: 'podman network restart' does not exist (networks are not restarted like services; containers are reconnected instead), and 'podman network upgrade' is not a Podman command, as network stack upgrades are handled through package management or 'podman system migrate' rather than a network subcommand.

Answer

podman network restart

Answer

podman network upgrade

Question 15

When publishing container ports using the Podman CLI, which THREE methods or syntaxes are valid for the -p / --publish flag? (Choose three)

Accepted Answer

-p 8080:80. Option A, `-p 8080:80`, is valid because the standard Podman/Docker publish syntax is `hostPort:containerPort`, mapping host port 8080 to container port 80 over the default TCP protocol. Option B, `-p 127.0.0.1:8080:80`, is valid because the full syntax `ip:hostPort:containerPort` binds the published port to a specific host interface (127.0.0.1) rather than all interfaces. Option E, `-p 8080:80/udp`, is valid because appending `/udp` (or `/tcp`) after the container port specifies the protocol for the published port. Option C is invalid because Podman does not accept the key=value form `container=80,host=8080` for `--publish`. Option D is invalid because the protocol must be appended with a slash (e.g., `8080:80/tcp`) and cannot be followed by an extra `:bind` field in that position.

Answer

-p container=80,host=8080

Answer

-p 80:8080:tcp:bind