Networking

Table of Contents

General description

CHARON-AXP supports emulation of the following network adapters:

• DE435
• DE450
• DE500AA
• DE500BA
• DE602
• DE602AA

Each of them is a PCI Ethernet adapter based on the DEC21040 (DE435, DE450, DE500AA and DE500BA) and the Intel i8255x (DE602 and DE602AA) PCI Ethernet adapter chips for the HP Alpha.

CHARON-AXP maps the virtual adapter to a dedicated Ethernet adapter in the Linux host system.

All the emulated controllers are loaded and configured in the same way.

 The Ethernet adapter in the Linux host system must support dynamic changes of its MAC address (i.e. no reboot of the host system is required to change the MAC address), which is the case with nearly all modern Ethernet adapters.

 By default the PCI Ethernet adapters use first available PCI slot. If instead some particular slot is needed, refer to this section for details of specific placement of PCI peripherals on CHARON-AXP PCI bus.

 Network booting is not currently supported.

Configuration steps

To configure CHARON-AXP networking, follow these 3 steps:

1. Load network adapter (if required)

   Use the "load" command as shown below.
   
   Example:

   For DEC21040 adapters	For Intel i8255x adapters
   load DE500BA/dec21x4x NIC	load DE602/i8255x NIC

   In AlphaStation 400 configuration use the following syntax for network adapter loading:

   load DE500AA/dec21x4x NIC irq_bus=isa

    By default each loaded virtual network adapter uses first available PCI slot. If instead some particular slot is neded, refer to this section for details of specific placement of PCI peripherals on CHARON-AXP PCI bus.
   
   

2. Load "packet_port" or "tap_port" 

   Load "packet_port" or "tap_port" to connect network adapter to the host hardware network card (or to a virtual network interface).
   
   Example:

   load packet_port/chnetwrk NDIS interface = "eth1"

3. Connect the loaded "packet_port" ("tap_port") to the loaded virtual network adapter

   Connect the network adapter to the "packet_port" ("tap_port") by setting the interface name.
   
   Example:

   set NIC interface = NDIS

Configuration parameters

Each virtual network controller has the following parameters that are specified with the "set" command:

interface

station_address

rx_fifo_size

adapter_mode

Example:

DE602 and DE602AA network adapters link speed and duplex settings

Regardless of the "adapter_mode" setting in CHARON-AXP configuration file (see above), DE602 and DE602AA network adapters remains in "Auto-negotiation" mode, since the EIDRIVER of OpenVMS checks for EIx0_MODE environment variable when configuring the network card.

So mode propagation is implemented in CHARON-AXP via SRM console EIx0_MODE environment variable ("x" is A, B, C... depending on CHARON-AXP configuration), for example:

 The EIx0_MODE variable name is case insensitive, while its values are case sensitive! This is feature of OpenVMS EIDRIVER.

The values are:

Example:

Packet Port

The CHARON-specific "packet_port" interface establishes a connection between an Ethernet adapter in the Linux host system and a network adapter in the virtual HP Alpha system.

For every virtual adapter instance loaded, one dedicated host Ethernet physical adapter is required.

To create instances of the "packet_port", use the “load” command in the configuration file as follows:

Example:

"packet_port" uses several configuration parameters to control its behavior.

interface

port_enable_mac_addr_change

port_retry_on_tx

port_pending_rx_number

port_pending_tx_number

log

Example