I only have serial access to a server, and I am trying to access its BIOS using telnet (it's not a direct serial, but a remote serial connection). My telnet certainly reaches the server, as I can see it's failed boot, but I want to restart it with Ctrl +Alt+Del, however this is captured by my local machine. F-keys also seem to be captured by my local machine.For the RHEL telnet application, what is the default method for issuing Ctrl +Alt+Del?For the RHEL telnet application, what is the default method for issuing F keys?
Ctrl + Alt + Del and F keys Using Telnet
rhel;telnet;serial console
Most bios accept various versions of the vt100 keyboard escape sequences for function keys. For example, the dell console redirection guide lists amongst others the equivalents:F7     <Esc> <Shift>ov  or   <Esc> [ 1 8 ~and also some extra non-standard sequences like<Ctrl><Alt><Del>   <Esc> <Shift>r <Esc> r <Esc> <Shift> r(For <Shift>ov you would type OV of course).  Unfortunately, these key sequences often have to be typed very rapidly, as only a small timeout is usually allowed between characters.One way of sending such a sequence through telnet is to get your terminal emulator to generate the string upon some binding.  This is very terminal emulator dependant.Another is to disconnect your telnet and run a command to send just the sequence through a new telnet connection. For example, for testing, this expect script does a login and sends the F7 sequence (\033\[18~). #!/bin/expect -fspawn telnet localhostexpect login:send myuserid\rexpect Password: send mypassword\rexpect \$ send echo hi\rexpect hiexpect \$ send dd count=6 bs=1 | od -c\rsend \033\[18~\rexpect \$send echo hi\rexpect hisend_user done\nObviously, you won't need to login to your bios, so you might just have#!/bin/expect -fspawn telnet remotebiosexpect Connected to send \033\[18~You can also try more simplyecho -e '\033[18~' | nc remotebios 23