Remote Console

Grant Peel gpeel at
Sun Oct 16 05:16:57 PDT 2005

Thanks Andrew,

So If I understand your reply, a setup like this should always give me 
access to any of the servers by SSHing to one server, then CUing to get to 
the console of the 'broken' one, regardless of its state (assuming the disks 
are OK, and boot stage 1 worked):

(WAN Shown, LAN Same, using seperate nics on Servers and Switch)

                                  ISP's router
                                    My Switch
|                  |                    |                   | 
Serv1            Serv2                Serv3               Serv4 


Can more than 1 console access type be specified in loader.conf ?

When using 'serial console, does anything have to be specified to use serial 

What is the default local console, how is it specified?
    i.e. the one you use when you plug a keyboard and monitor directly into 
the machine?

Would I need to install any other software other than the client (CU)?


----- Original Message ----- 
From: "Andrew P." <infofarmer at>
To: "Grant Peel" <gpeel at>
Cc: <freebsd-questions at>
Sent: Sunday, October 16, 2005 7:32 AM
Subject: Re: Remote Console

On 10/16/05, Grant Peel <gpeel at> wrote:
> Hi all,
> I have asked this question before, so if it looks familiar ...
> I am hoping all the reading I have done over the past few weeks makes this
> instance of the qeustion clearer.
> Background:
> 1 Dell 24 Port Switch, WAN connection to my ISP.
> 5 Dell Serers, each with 2 NICs.
>     1 NIC on each connected to SWITCH - VLAN 1 -WAN (Many different IP's).
>     1 NIC on each connected to SWITH - VLAN 2 -LAN (192.168.0/24)
>     Each Server has 2 Serial ports, unused.
>     Each Server has 2 USB ports, unused.
> All servers running FreebSD
>     2 Running 4.10
>     1 Running 5.2.1
>     1 Running 5.4
>     1 Running 4.4 (Slave3 Nameserver only).
> I am ~ 120 miles from the server cage these are located in. So traveling 
> to
> there is a real pain.
> I have been reading everything I can find on consoles, ttys, blackboxes,
> Lantronix serial cables etc, etc ,etc ,etc ...
> What I am looking to do, is to connect all the servers to a device, or,
> daisychain them together so that even if I reboot a broken machine, I can
> still get to a "boot ?" prompt, not to mention single user mode and normal
> ssh shell prompt. (of course I already have the latter through IP when the
> machine boots correctly.
> So my question is, can a machine be made to still be remotely accessable
> (any method), when file systems are not mounted, or, kernel not loaded? If
> so, using what setup?
> -Grant
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> "freebsd-questions-unsubscribe at"

First, you should check with your servers' specs.
Many vendors include basic LOM (Lights-out-
management) support in their boxes. If they do,
you should turn it on in the BIOS - and it will
redirect all text-based screen output and keyboard
input to a COM port. If all goes right, you'll be able
to even edit your BIOS settings remotely.

Secondly, you can place "console comsonsole"
line in /boot/loader.conf. That should allow you
to access that "boot ?" prompt.

Thirdly (preferred method for servers without
good LOM) - you can buy a 3d-party LOM,
available in a dozen of forms, from PCI and
what not cards to KVM-over-IP solutions.

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