28. ROX™ Routing Overview
ROX™ v2.2 User Guide
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RuggedBackbone™ RX5000
28. ROX™ Routing Overview
This section provides an overview of IP routing in ROX™. This section describes how ROX™ configures
physical Ethernet ports, and how ROX™ switches and routes IP packets.
28.1. IP Routing in ROX™
ROX™ supports multiple interface types and can perform Ethernet Switching (Layer 2), IP switching
(Layer 3), and Software routing depending on the type of physical interface. Almost all interface types
support IP addresses in ROX™.
28.2. Physical Ethernet Port Types in ROX™
ROX™ supports two types of Ethernet ports: switch ports and router (Ethe) ports:
• A switch port is one in which packet switching is performed in the underlying hardware. By default,
all switch ports belong to VLAN 1.
• A router port is one in which packet switching is managed entirely in software. Router ports are usually
independent of other ports or interfaces and are managed as such. Hardware acceleration cannot
be performed on router ports.
On the RX1500-series and RX5000 platforms, all Ethernet ports except for cm/1 are switch ports. On
the RX1000-series platforms, all Ethernet ports are router ports.
28.3. Routing
28.3.1. Using VLAN Interfaces for Routing and Layer 3 Switching
When a VLAN interface is configured with an IP address, ROX™ hosts the IP on the LAN segment. This
means that any devices belonging to that VLAN can reach the IP address, provided that the devices’
IP addresses belong to the same subnet.
For example, assume that lm1/1, lm1/2, and lm1/5 belong to VLAN 100 and the attached devices
have the IP addresses 192.168.100.1/24, 192.168.100.2/24, and 192.168.100.3/24. At this point, the
ROX™ device does not have an IP address for VLAN 100, but it has an IP address for VLAN 1. In this
example, devices attached to lm1/1, lm1/2, and lm1/5 can communicate among themselves, but their
LAN segment is essentially isolated and they cannot reach anywhere else.
Figure 28.1. Three interfaces on an isolated VLAN
Whenever you create a VLAN in ROX™, a corresponding interface with no IP address is also created.
This interface is accessible to devices attached to that VLAN.