Information About EtherType Rules

Chapter 7 Configuring Access Rules

Information About Access Rules

Table 7-1lists common traffic types that you can allow through the transparent firewall.

Table 7-1	Transparent Firewall Special Traffic

Traffic Type		Protocol or Port	Notes

DHCP		UDP ports 67 and 68	If you enable the DHCP server, then the ASA
			does not pass DHCP packets.

EIGRP		Protocol 88	—

OSPF		Protocol 89	—

Multicast streams		The UDP ports vary depending	Multicast streams are always destined to a
		on the application.	Class D address (224.0.0.0 to 239.x.x.x).

RIP (v1 or v2)		UDP port 520	—

Management Access Rules

You can configure access rules that control management traffic destined to the ASA. Access control rules for to-the-box management traffic (such as HTTP, Telnet, and SSH) have higher precedence than an management access rule. Therefore, such permitted management traffic will be allowed to come in even if explicitly denied by the to-the-box ACL.

This section describes EtherType rules and includes the following topics:

•Supported EtherTypes and Other Traffic, page 7-6

•Access Rules for Returning Traffic, page 7-7

•Allowing MPLS, page 7-7

Supported EtherTypes and Other Traffic

An EtherType rule controls the following:

•EtherType identified by a 16-bit hexadecimal number, including common types IPX and MPLS unicast or multicast.

•Ethernet V2 frames.

•BPDUs, which are permitted by default. BPDUs are SNAP-encapsulated, and the ASA is designed to specifically handle BPDUs.

•Trunk port (Cisco proprietary) BPDUs. Trunk BPDUs have VLAN information inside the payload, so the ASA modifies the payload with the outgoing VLAN if you allow BPDUs.

•IS-IS.

The following types of traffic are not supported:

•802.3-formatted frames—These frames are not handled by the rule because they use a length field as opposed to a type field.

Cisco ASA Series Firewall ASDM Configuration Guide

7-6

ASA Services Module, ASA 5555-X, ASA 5545-X, ASA 5585-X, ASA 5580 specifications

Cisco Systems has long been a leader in the field of network security, and its Adaptive Security Appliance (ASA) series is a testament to this expertise. Within the ASA lineup, models such as the ASA 5505, ASA 5580, ASA 5585-X, ASA 5545-X, and ASA 5555-X stand out for their unique features, capabilities, and technological advancements.

The Cisco ASA 5505 is designed for small businesses or branch offices. It provides essential security features such as firewall protection, flexible VPN capabilities, and intrusion prevention. The ASA 5505 supports a user-friendly interface, allowing for straightforward management. Its built-in threat detection and prevention tools provide a layered defense, and with scalability in mind, it can accommodate various expansion options as organizational needs grow.

Moving up the line, the ASA 5580 delivers greater throughput and advanced security features. This model is suited for medium to large enterprises that require robust protection against increasingly sophisticated threats. Its multi-core architecture allows it to manage high volumes of traffic seamlessly while maintaining excellent performance levels. The ASA 5580 also supports application-layer security and customizable access policies, making it highly adaptable to diverse security environments.

The ASA 5585-X further enhances Cisco's security offerings with advanced malware protection and extensive security intelligence capabilities. It incorporates next-generation firewall features, including context-aware security, and supports advanced threat detection technologies. This model is ideal for large enterprises or data centers that prioritize security while ensuring uninterrupted network performance and availability.

For enterprises requiring a balance of performance and security, the ASA 5545-X presents a compelling option. This model features scalable performance metrics, high availability, and integrated advanced threat protection. Coupled with advanced endpoint protection and detailed monitoring capabilities, the ASA 5545-X enables organizations to manage their security posture effectively.

Lastly, the ASA 5555-X blends cutting-edge technologies with strong security infrastructures. It boasts high throughput and the ability to execute deep packet inspections. Its sophisticated architecture supports threat intelligence feeds that provide real-time security updates, making it a powerful tool against modern threats.

Each of these Cisco ASA models brings specific advantages to varied environments. Their integrative capabilities enable businesses to enhance their security postures while benefiting from seamless scalability and management. As cybersecurity threats evolve, these advanced appliances play a vital role in protecting valuable digital assets.

Cisco Systems ASA 5555-X, ASA 5505 Information About EtherType Rules, Management Access Rules

Models: ASA Services Module ASA 5555-X ASA 5545-X ASA 5585-X ASA 5580 ASA 5505

Traffic Type

Protocol or Port

OSPF

Management Access Rules