Firewall Configuration: Single-Homed Bastion Host

Questions and Answers

Improperly secured WLAN against external use

To examine each IP packet and permit or deny according to rules

Permissive and conservative

To restrict access to services and ports Signup and view all the answers

Packet filter Signup and view all the answers

Packet filter Signup and view all the answers

Conservative Signup and view all the answers

To restrict access to services and ports Signup and view all the answers

Between the internal and external networks Signup and view all the answers

To make decisions on allowable traffic flows Signup and view all the answers

Study Notes

A single-homed bastion host can be compromised if the packet-filtering router is compromised, allowing external bogus traffic to reach internal servers.
A screened host firewall with a single-homed bastion host configuration provides greater security, implementing both packet-level and application-level filtering.

A dual-homed bastion host physically separates external and internal networks, requiring two systems to be compromised for a breach.
This configuration provides dual layers of security and allows for direct Internet access to specific internal servers if desired.

An internal firewall adds more stringent filtering capability to protect enterprise servers and workstations from external attacks.
The internal firewall provides two-way protection: protecting the internal network from DMZ system attacks and protecting DMZ systems from internal network attacks.
Multiple internal firewalls can be used to protect portions of the internal network from each other.

A distributed firewall configuration involves stand-alone firewall devices and host-based firewalls working together under central administrative control.
This configuration allows for protection against internal attacks and tailored protection for specific machines and applications.

There are four common types of firewalls: packet filters, stateful packet filters, application-level gateways, and circuit-level gateways.

Packet filters are the simplest and fastest firewall component, examining each IP packet and permitting or denying access according to rules.
They restrict access to services (ports) and can have default policies, either prohibiting access by default or permitting access by default.
Packet filters can be placed in a border router between the external Internet and internal private network, utilizing information from transport, network, and data link layers to make decisions on allowable traffic flows.