IPMI 2.0 includes serial over LAN, but that's text only console redirection. If you want graphical console redirection, you need to use a proprietary tool from your vendor,
I... don't. Why would I? Both Linux and Windows (since 2003 with EMS) lets you do any system fixing & reconfiguration you could want, via serial console.
With OoBM, you really only need to get your system booting again, and network reconfigured and working. After that, you connect via in-band management, whether that's SSH, RDP, NX, VNC, etc. It's stupid, wrong, and terribly inefficient to use your OoBM for all your system management.
If you're running graphical Linux, you need graphical console redirection
Bullshit. You mean if you don't have a clue how to manage the basics on a Linux system without the GUI, THEN you're in trouble if you don't have graphical console redirection.
You get power on, off, cycle, read the (hardware) system event log, configure the network settings of the BMC, and console redirection to a serial port. For Dell, you also have to enable redirection via COM2 in the BIOS if you want serial over LAN.
As I said before, IPMI also enables you to change BIOS settings. You can "enable redirection via COM2 in the BIOS" directly & remotely via IPMI, without ever entering the BIOS. It's a simple one-liner. Then you
The "redirection" isn't even really needed, except for seeing BIOS messages on boot-up. Otherwise you just need to tell your OS to enable a console on serial, and you're fine.