Preparation for your network environment
To prepare for your network environment, you need to identify and comply with the minimum network configuration required to set up an Operations Console local console on a network (LAN) configuration.
If your system is new and you chose a local console on a network configuration, the adapter is already allocated for use by the system. The LAN adapter is dedicated for service tools. It is suggested that you restrict LAN topologies for LAN-attached local consoles to a single, physical ring, hub, switch, or router environment. If the local console on a network is used in a larger network topology, it is suggested that you use broadcast (DHCP) packet filtering. This might be as simple as connecting the PC and system using an inexpensive hub or router. Temporarily, you could also use an Ethernet crossover cable (when using a 2849 adapter). When you have only a single PC or few devices connected to the system using a hub, and these devices do not connect to another network or the Internet, you can then use any numeric numbers for addresses, for example, 1.1.1.x or 10.220.215.x (where x can be 2 through 254, but avoid x.x.x.1, which might cause problems in some hubs). However, if you have a network that many users share, or in which the devices are connected to the Internet, consult a network administrator for addresses.
A crossover cable is a standard network cable that has the transmit and receive signal wires reversed. This virtually allows each end to act as if a hub, switch, or router were between them. The use of a crossover cable might also require a nonstandard network configuration at the system and PC.
Network security
It is suggested that you treat the console over a LAN connection with the same physical security considerations and controls a twinaxial console. For instance, consider configuring a local console on a network separate from the main network (or the company intranet) and strictly controlling access to the PC that acts as the console.
BOOTstrap Protocol
A local Operations Console on a network uses the BOOTstrap Protocol (BOOTP) to configure the system service IP communications stack. The IP stack configuration plus the system serial number and the partition ID are requested in the Operations Console configuration wizard. The system broadcasts a BOOTP request. The Operations Console PC replies with the information submitted during the configuration wizard. The system then stores and uses the configuration information for the service IP communications stack.
The system will perform a BOOTP when the console type is set to Operations Console (LAN) and the system does not contain a valid IP address for the service host name (service interface).
The Operations Console PC must be placed on a network that can be accessed by the system. This can be the same physical network or a network that permits broadcast packets to flow. This is an initial setup requirement. Normal Operations Console operation does not require this. It is suggested that this setup occur on the same physical network.
Starting
with IBM® i 6.1,
Operations Console can detect systems capable of being configured
with less user interaction. If this condition is detected, the PC
and system attempt to exchange information for a new configuration.
If the information exchange is successful, the system uses this information
during the setup of the connection at the PC. This detection reduces
mistakes caused by entering the wrong IP address or the partition
ID. This detection can take place only if both the PC and the system
are running 6.1 or later. Otherwise, a traditional BOOTP takes place
and you must supply all the data for the system.
The BOOTP request carries the system serial number and partition ID. The system serial number and partition ID are used to assign the IP configuration information. If you are having problems configuring the service IP communications stack, verify that the Operations Console PC is on the same physical network, and that the system serial number and partition ID are correct in the configuration.
A local
console on a network (LAN) uses ports 2300, 2323, 3001, and 3002.
To use Operations Console in a different physical network the router
and firewall must allow IP traffic on these ports.
The success of BOOTP is dependent on the network hardware used to connect the system and the PC. In some cases, you might need a different device to configure a console connection using system service tools (SST). To use BOOTP, the network hardware used must be capable of autonegotiation of speed and duplex when using the 2838 Ethernet Adapter for the Operations Console connection.
Although the system and PC can still perform a standard BOOTP operation as described here, beginning in 6.1 a function was added to allow the automatic discovery of a connection between the system and a PC. This function, called VSDISCOVER, is a proprietary mechanism used solely for Operations Console. Both the system and PC listen for a special broadcast frame from the network and when received there is a negotiation using ports 67 and 68 and the system and PC can use the data exchanged to configure itself, if needed. In addition, the PC creates a configured connection that the user can start a console session with. This VSDISCOVER function is the default mechanism for configuring a connection. The BOOTP process is used when VSDISCOVER is not necessary, such as when you already have a configured connection and the network data needs to be reset for some reason.