• SonicOS 7.0
• Overview
  • About SonicOS
  • SonicOS Workflow
  • How to Use the SonicOS Administration Guides
  • Guide Conventions
• Interfaces
  • About Interfaces
    • Physical and Virtual Interfaces
      • Physical Interfaces
      • Virtual Interfaces (VLAN)
      • Subinterfaces
    • SonicOS Secure Objects
    • One Arm Mode and Single Interface Support
    • Transparent Mode
    • IPS Sniffer Mode
      • Sample IPS Sniffer Mode Topology
    • Firewall Sandwich
    • HTTP/HTTPS Redirection
      • HTTP/HTTPS Redirection with DP Offload
    • Enabling DNS Proxy on an Interface
    • LTE Modem Support
    • LAN Bypass
  • Interface Settings IPv4
    • Adding Virtual Interfaces
      • Configuring General Settings for Virtual Interface
      • Configuring Advanced Settings for a Virtual Interface
      • Configuring Virtual Interfaces (VLAN Subinterfaces)
    • Configuring Routed Mode
    • Enabling Bandwidth Management on an Interface
    • Configuring Interfaces in Transparent IP Mode (Splice L3 Subnet)
      • Configuring Advanced Settings for a Transparent IP Mode Interface
    • Configuring Wireless Interfaces
      • Configuring Advanced Settings for a Wireless Interface
    • Configuring WAN Interfaces
      • Configuring Advanced Settings for a WAN Interface
      • Configuring Protocol Settings for a WAN Interface
    • Configuring Tunnel Interfaces
    • Configuring VPN Tunnel Interfaces
    • Configuring Link Aggregation and Port Redundancy
      • Link Aggregation
        • Link Aggregation Failover
        • Link Aggregation Limitations
        • Link Aggregation Configuration
      • Port Redundancy
        • Port Redundancy Failover
        • Port Redundancy Configuration
    • Configuring One Arm Mode
    • Configuring an IPS Sniffer Mode Appliance
      • Configuration Task List for IPS Sniffer Mode
      • Configuring the Primary Bridge Interface
      • Configuring the Secondary Bridge Interface
      • Configuring SNMP
      • Configuring IPS Sniffer Mode
    • Configuring Security Services (Unified Threat Management)
      • Configuring Logging
      • Connecting a Mirrored Switch Port to an IPS Sniffer Mode Interface
      • Connecting and Configuring a WAN Interface to the Data Center
    • Configuring Wire and Tap Mode
      • Configuring an Interface for Wire Mode
      • Configuring Wire Mode for a WAN/LAN Zone Pair
      • Configuring Wire Mode with Link Aggregation
    • Layer 2 Bridged Mode
      • Key Features of SonicOS Layer 2 Bridged Mode
      • Key Concepts to Configuring L2 Bridged Mode and Transparent Mode
      • Comparing L2 Bridged Mode to Transparent Mode
        • Comparison of L2 Bridged Mode to Transparent Mode
        • Benefits of Transparent Mode over L2 Bridged Mode
        • ARP in Transparent Mode
        • VLAN Support in Transparent Mode
        • Multiple Subnets in Transparent Mode
        • Non-IPv4 Traffic in Transparent Mode
        • ARP in L2 Bridged Mode
        • VLAN Support in L2 Bridged Mode
        • L2 Bridge IP Packet Path
        • Multiple Subnets in L2 Bridged Mode
        • Non-IPv4 Traffic in L2 Bridged Mode
      • L2 Bridge Path Determination
      • L2 Bridge Interface Zone Selection
        • Security Services Directionality
        • Access Rule Defaults
        • WAN Connectivity
      • Sample Topologies
        • Wireless Layer 2 Bridge
        • Inline Layer 2 Bridged Mode
        • Perimeter Security
        • Internal Security
        • Layer 2 Bridged Mode with High Availability
        • Layer 2 Bridged Mode with SSL VPN
        • WAN to LAN Access Rules
      • Configuring Network Interfaces and Activating L2B Mode
        • Installing the Appliance between the Network and an SSL VPN Appliance
        • Configuring or Verifying Settings
      • Configuring Layer 2 Bridged Mode
        • Configuration Task List for Layer 2 Bridged Mode
        • Configuring the Common Settings for L2 Bridged Mode Deployments
          • Licensing Services
          • Disabling a DHCP Server
          • Configuring SNMP Settings
          • Enabling SNMP and HTTPS on the Interfaces
          • Enabling Syslog
          • Activating Security Services on Each Zone
          • Creating Access Rules
          • Configuring Log Settings
          • Configuring Wireless Zone Settings
        • Configuring Layer 2 Bridged Mode Procedure
          • Configuring the Primary Bridge Interface
          • Configuring the Secondary Bridge Interface
          • Configuring an L2 Bypass for Hardware Failures
        • VLAN Integration with Layer 2 Bridged Mode
        • VPN Integration with Layer 2 Bridged Mode
      • Asymmetric Routing
    • Configuring Interfaces for IPv6
  • 31-Bit Network Settings
    • 31-Bit Network Environment Example
    • Configuring a 31-Bit Network in SonicOS
  • PPPoE Unnumbered Interface Support
    • Sample Network Topography
    • Caveats
    • Configuring a PPPoE Unnumbered Interface
    • Configuring HA with PPPoE Unnumbered
• Failover & LB
  • Settings
  • Groups
  • Statistics
• Neighbor Discovery
  • NDP Cache
    • Flushing the NDP Cache
  • Static NDP Entries
    • Adding Static NDP Entries
    • Editing Static NDP Entries
    • Deleting Static NDP Entries
  • NDP Settings
• ARP
  • ARP Cache
    • Flushing the ARP Cache
  • Static ARP Entries
    • Viewing Static ARP Entries
    • Adding Static ARP Entries
    • Editing Static ARP Entries
    • Deleting Static ARP Entries
    • Secondary Subnets with Static ARP
      • Adding a Secondary Subnet
        • Secondary Subnet Example
  • ARP Settings
• MAC IP Anti-Spoof
  • MAC IPv4 and IPv6 Anti-Spoof Settings
  • Configuring MAC IP Anti-Spoof Settings
  • Anti-Spoof Cache
  • Spoof Detected List
• Web Proxy
  • User Proxy Servers
  • Proxy Forwarding
    • Adding User Proxy Servers
    • Editing User Proxy Servers
    • Deleting User Proxy Servers
• PortShield Groups
  • SonicOS Support of X-Series Switches
    • About the X-Series Solution
    • Performance Requirements
    • Key Features Supported with X-Series Switches
    • PortShield Functionality and X-Series Switches
      • Different Traffic Scenarios with PortShield
      • Prerequisites for PortShielding X-Series Switches
      • Dell X-Series Daisy-Chaining Support
        • Assumptions and Dependencies
        • Daisy-chaining Support
    • PoE/PoE+ and SFP/SFP+ Support
    • X-Series Solution and SonicPoints
    • Managing Extended Switches using GMS
    • Extended Switch Global Parameters
    • About Links
      • About Uplink Interfaces
      • Criteria for Configuring an Uplink Interface
    • Logging and Syslog Support
  • Supported Topologies
  • Port Graphics
  • Port Configuration
  • External Switch Configuration
  • External Switch Diagnostics
    • Switch Information
    • Statistics
    • Firmware Management
  • Configuring PortShield Groups
    • Configuring PortShield Interfaces on NETWORK | System > Interfaces
    • Configuring PortShield Interfaces with the PortShield Interface Guide (TZ Series Firewalls Only)
    • Configuring PortShield Interfaces on NETWORK | System > PortShield Groups
    • Configuring External Switch PortShield Groups from Port Graphics
• PoE Settings
  • Enabling PoE on the Appliance
• VLAN Translation
  • Mapping Modes
  • Mapping Persistence
  • Map Multiple Interface Pairs
  • Creating and Managing VLAN Maps
    • Creating a VLAN Map
      • Creating a Wire Mode Pair in Secure Mode
      • Creating the VLAN Mapping
    • Managing VLAN Mappings
      • Editing Mappings
      • Filtering Mappings
      • Deleting Mappings
• IP Helper
  • Using IP Helper
    • About IP Helper
      • VPN Tunnel Interface Support for IP Helper
      • DHCPv6 Relay
        • About DHCPv6 Relay
        • Configuring DHCPv6 Relay
    • IP Helper Settings
      • Relay Protocols
      • Policies
      • DHCP/DHCPv6 Relay Leases
  • Configuring IP Helper
    • Enabling IP Helper
    • Managing Relay Protocols
      • Adding User-Defined Relay Protocols
      • Deleting Custom Protocols
    • Managing IP Helper Policies
      • Adding an IP Helper Policy
      • Editing an IP Helper Policy
      • Deleting IP Helper Policies
    • Filtering which DHCP Relay Leases are Displayed
    • Displaying IP Helper Cache from TSR
• Dynamic Routing
  • Route Advertisement
  • OSPFv2
    • General Settings
  • OSPFv3
  • RIP
  • RIPng
  • Settings
• DHCP Server
  • Configuring a DHCP Server
    • Configuring the DHCP Server Settings
      • Configuring the DHCP Server for DNS Proxy
    • Configuring DHCP Server Lease Scopes
    • Current DHCP Leases
      • Current DHCP Leases IPv4
      • Current DHCP Leases IPv6
    • DHCPv6 Relay
  • Configuring Advanced Options
    • Configuring DHCP Option Objects
    • Configuring DHCP Option Groups
    • Configuring a Trusted DHCP Relay Agent Address Group (IPv4 Only)
    • Enabling Trusted DHCP Relay Agents
    • Configuring IPv4 DHCP Servers for Dynamic Ranges
      • Add DHCP Dynamic Scope
      • DNS/WINS
      • Advanced
    • Configuring IPv6 DHCP Servers for Dynamic Ranges
      • Add DHCPv6 Dynamic Scope
      • DNS
      • Advanced
    • Configuring IPv4 DHCP Static Ranges
      • Adding Static Range Configuration Settings
    • Configuring IPv6 DHCP Static Ranges
    • Configuring DHCP Generic Options for DHCP Lease Scopes
      • RFC-defined DHCP Option Numbers
    • DHCP and IPv6
• Multicast
  • Multicast Policies
    • Creating a Multicast Address Object
    • Creating a New Multicast Address Group
  • IGMP State
  • Enabling Multicast
    • Enabling Multicast on a LAN-Dedicated Interface
    • Enabling Multicast Support for Address Objects over a VPN Tunnel
• Network Monitor
  • About Network Monitor Policies
  • Configuring Network Monitor Policies
  • Deleting Network Monitor Policies
• AWS Configuration
  • AWS Security Credentials
    • IAM Group and User
  • Firewall Configuration
    • Test Connection
• SonicWall Support
  • About This Document

One Arm Mode and Single Interface Support

One Arm Mode is when only one firewall interface is used, and all traffic comes into and out from the same interface. It is possible to apply security rules and Deep Packet Inspection (DPI) scans on data traffic from the One Arm interface. Data received from this interface is scanned by SonicOS security services and then sent out on this interface.

One example usage scenario is shown as follows for SonicWall Cloud Edge. Cloud Edge works well when using a single interface on the firewall where traffic comes into and goes out from the same interface.

For One Arm Mode, you need to configure the interface:

• Interface must have a valid IP address (IPv4 or IPv6) configured. This can be a static IP address or a DHCP address.
• Must have One Arm Peer (next hop IP address) configured.
• Only LAN or WAN zone interfaces allow One Arm Mode in SonicOS 7.0.

When you complete the One Arm Mode interface configuration, SonicOS automatically updates the system configuration to support One Arm Mode.

If the One Arm Mode interface is in the LAN zone, options on the NETWORK | Firewall > Advanced page are enabled or disabled. These are under ACCESS RULE OPTIONS:

• Enable Apply firewall rules for intra-LAN traffic to/from the same interface - enable LAN-to-LAN security scanning

• Disable Enable ICMP Redirect on LAN zone - disable ICMP redirect if One Arm Mode interface is in LAN zone

  

An address object for the One Arm Peer is automatically created.

A security policy to allow traffic from One Arm Mode interface to One Arm Mode interface is automatically created so traffic is always allowed.

A routing policy is automatically added with the One Arm Peer as the gateway to allow other traffic to apply One Arm routing, if needed.

For using a single interface on the firewall, the minimum number of NIC is changed to 1. To use only X0, you need to shut down X1 to make all traffic go out from X0. When you shut down X1, the priority of the One Arm routing policy becomes higher than the default route priority and traffic uses the X0 One Arm routing policy.

For configuration of a One Arm Mode interface, see Configuring One Arm Mode.