Sol Overview; General Rules To Establish An Sol Connection - IBM Nortel Networks L2/3 Manual

8.1 SOL overview

SOL is accomplished in the following way: Serial data that flows to and from the blade
server(s) COM port is routed through the network infrastructure of the BladeCenter chassis.
This network infrastructure includes the BladeCenter Management Module, the Nortel
Networks L2/3 GbESM, and the onboard network adapter of the blade server. In addition, the
blade server's integrated system management processor also assists in handling the serial
data to and from the COM port.
The BladeCenter Management Module acts as a proxy during a SOL connection from a
workstation in the network and the blade server in the BladeCenter chassis. First, the
workstation uses telnet to establish a link with the Management Module. When the link is
established through telnet, the workstation can then pass a command to the Management
Module to interact with the serial port of any blade server in that BladeCenter chassis.
Note: The traffic path of SOL along the network is through the Management Module. It is
not possible to establish a SOL session to a blade server by going through the external
ports of the switch.

8.2 General rules to establish an SOL connection

To initiate an SOL connection to a blade server, you must first establish a telnet session to
the BladeCenter Management Module where the blade server is located. When the telnet
session has been established, you can initiate a remote console SOL session to any blade
server using the CLI of the Management Module. General rules for establishing this
connection are:
You can establish as many as 20 separate telnet sessions to one BladeCenter
Management Module. This gives the ability to have one SOL session active on all 14
blade servers in the BladeCenter chassis and also have six additional CLI sessions for the
Management Module itself.
If security is a concern, Secure Shell (SSH) sessions are also available so users can
establish secured telnet CLI sessions to the Management Module prior to starting an SOL
console redirect session to the blade server.
Telnet sessions with the Management Module have a default timeout value of 120
seconds. If there is no telnet or SOL traffic within the timeout interval, the telnet session
itself terminates.
SOL uses the first network interface (Planar Ethernet 1) of the blade server to
communicate. When this interface attempts to boot through PXE or DHCP, the network
interface is reset, causing the SOL connection to drop. If booting through PXE or DHCP is
required, it is recommended that the second network interface of the blade server is used
(Planar Ethernet 2). This can be set in the blade server's BIOS settings.
JS20 model blade servers require SOL for video purposes during the operating system
install at least. After the operating system is installed the user can use other methods over
the blade server's Ethernet interface(s) for administration (SSH for example). If BOOTP is
needed for JS20, again, the second network interface is recommended.
There are no specific rules that apply to the Nortel Networks L2/3 GbESM itself. The switch
by default reserves VLAN 4095 for SOL traffic.
Nortel Networks L2/3 Ethernet Switch Module for IBM Eserver BladeCenter
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