Re: network type console and /etc/ttys
Matthew Seaman [EMAIL PROTECTED] writes: On Mon, Mar 08, 2004 at 01:07:09PM -0800, Gary W. Swearingen wrote: Seems like basic stuff, but I've never seen mention of it before. Actually this comes up on this list quite regularly. Search for 'remote console access' in the list archives. The trick, basically, is to tell the system to use Serial A as it's console -- how to do that is described in the Handbook: Thanks, but as you noted, it's not hard to find info about remote serial port consoles. My question was about doing a similar thing over Ethernet. That is, with a single Ethernet cable between the local NIC and the remote NIC, not necessarily on a real, many-port network, and definitely without telnet, ssh, and other network services running -- so that it works from single-user mode, working just like a serial console. I'm sure the Ethernet support is mostly there in the kernel, but maybe something fairly simple is missing from whatever reads /etc/ttys; eg, to know which NIC is to be the console port), and maybe there needs to be an ethernet-getty (similar to telnet, but which needn't even use IP addresses). And maybe a ethconsole addition to comconsole and vidconsole in /boot/loader.conf. Maybe I'm missing something, but it seems like this would be a often- used feature, especially as RS-232 serial ports will probably be disappearing from new motherboards in the next few years. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: network type console and /etc/ttys
On Tue, Mar 09, 2004 at 11:27:35AM -0800, Gary W. Swearingen wrote: Matthew Seaman [EMAIL PROTECTED] writes: On Mon, Mar 08, 2004 at 01:07:09PM -0800, Gary W. Swearingen wrote: Seems like basic stuff, but I've never seen mention of it before. Actually this comes up on this list quite regularly. Search for 'remote console access' in the list archives. The trick, basically, is to tell the system to use Serial A as it's console -- how to do that is described in the Handbook: Thanks, but as you noted, it's not hard to find info about remote serial port consoles. My question was about doing a similar thing over Ethernet. That is, with a single Ethernet cable between the local NIC and the remote NIC, not necessarily on a real, many-port network, and definitely without telnet, ssh, and other network services running -- so that it works from single-user mode, working just like a serial console. I'm sure the Ethernet support is mostly there in the kernel, but maybe something fairly simple is missing from whatever reads /etc/ttys; eg, to know which NIC is to be the console port), and maybe there needs to be an ethernet-getty (similar to telnet, but which needn't even use IP addresses). And maybe a ethconsole addition to comconsole and vidconsole in /boot/loader.conf. Well, yes. Most console servers do that by providing ethernet access nowadays. The ethernet-getty you describe can't work: there's nothing special about getty per-se, that's just a process that handles activity on some terminal. It doesn't even come into single user mode or the early stages of the boot process. The network functionality you want is provided precisely by telnetd(8) or rshd(8) or more usually sshd(8). However, you can't use those for the console, because the console has to operate independantly of the state of the OS. It's pretty pointless having a remote console if you can't type 'boot' into it. And it's hard to have the network interface configured and up, with network comms programs running when the system is sitting at the boot-loader prompt. Maybe I'm missing something, but it seems like this would be a often- used feature, especially as RS-232 serial ports will probably be disappearing from new motherboards in the next few years. Maybe the RS-232 serial ports will disappear, but the USB serial ports will still exist. This sort of functionality is far too important for a serious mother board manufacturer to ever consider leaving out of a server class system. Maybe it will be a different to what we use today, but something with similar capabilities will exist. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK pgp0.pgp Description: PGP signature
Re: network type console and /etc/ttys
Matthew Seaman [EMAIL PROTECTED] writes: ... It's pretty pointless having a remote console if you can't type 'boot' into it. And it's hard to have the network interface configured and up, with network comms programs running when the system is sitting at the boot-loader prompt. H. I was thinking that the serial port only got into the picture after the kernel was loaded and / was mounted so /etc/ttys could be read to configure the console, but you remind me that it comes into play during a mid-phase of the boot loading. So what I'm looking for would require a considerable change to the boot loader. I wonder if it has to fit into a few (up to about 15, IIRC) boot records, or if it could use some code under /boot/? Oh well, you've convinced me that Ethernet consoles can't be easily supported (though it still seems useful enough that someone would have done it by now). Thanks. ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: network type console and /etc/ttys
On Mon, Mar 08, 2004 at 01:07:09PM -0800, Gary W. Swearingen wrote: /etc/ttys has a field called type and says that network is an option, but I can't find that expanded upon in its manpage or in the Handbook or FAQ. I've tried googling, but my searches either return a small list with no relevant info or a huge list that seems to be all off topic. The file has network for Pseudo terminals (ttyp#), but that isn't enough of a clue for me, either. The pseudo-terminal entries are used in a) xterm windows and b) when you telnet or ssh into the system remotely. It's basically a software construct that behaves like a real physical terminal. However, it's not sufficiently like an actual terminal that you can use it instead of one. The basic question is whether and how one can set up a remote (LAN) terminal, probably using that network type in /etc/ttys (without using X11). How does one specify which network port, for example? It seems like it should be handled very much like setting up a RS-232-type serial terminal. Just ssh into the box over the network -- the 'tty' command will tell you your terminal is '/dev/ttyp1' - that 'p' in the name (or 'q' or 'r' or 's' or 'P' or 'Q' or 'R' or 'S') indicates a pseudo-terminal. (real terminals are called something like /dev/console, /dev/tty, /dev/ttyv1 (for the console virtual terminals) or /dev/ttyd1 (for RS-232-type serial terminals)) The original problem was whether and how one can do that for the console terminal, to support even single-user mode. Seems like basic stuff, but I've never seen mention of it before. Actually this comes up on this list quite regularly. Search for 'remote console access' in the list archives. The trick, basically, is to tell the system to use Serial A as it's console -- how to do that is described in the Handbook: http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/install-advanced.html http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/serialconsole-setup.html Now, setting up a remotely accessible console can be as simple as stringing a null-modem cable between the serial port on that machine and another one that happens to be near by, and using tip(1) as a terminal emulator on the other machine. Or it can be solved by throwing money and hardware at the problem -- for instance Lightwave (now part of Lantronix) make a nice range of console server equipment. One particularly amusing solution is RealWeasel -- mostly because of the cartoon on the front page of their web site: http://www.realweasel.com/ There's also this article on the FreeBSD site about using console servers: http://www.freebsd.org/doc/en_US.ISO8859-1/articles/console-server/index.html Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 26 The Paddocks Savill Way PGP: http://www.infracaninophile.co.uk/pgpkey Marlow Tel: +44 1628 476614 Bucks., SL7 1TH UK pgp0.pgp Description: PGP signature
