Console (SSH / Telnet / Serial)

What it does: connects over SSH (encrypted), Telnet (plaintext), or a local serial/COM port straight into a device's console — the pre-network way in for factory-fresh gear that has no IP configured yet. Same command box, same history, same safety gating every way. SSH supports password auth (the usual choice for initial setup, since a fresh device has no key trust established) or key-based auth for gear you've already provisioned with one.

Telnet: for gear whose crypto/SSH isn't enabled yet, or that has no key or license for it — a common reality on brand-new or lab switches. There are no username/key fields: Telnet login is in-band, so you connect to just a host and port (23), then answer the device's own Username:/Password: prompts in the command box (which masks what you type on a password prompt). WARNING: Telnet is UNENCRYPTED — your credentials and every keystroke cross the network in clear text. Use it only when SSH isn't available, and prefer a trusted or console/management network; switch the device to SSH as soon as you can.

Safe to run: with care — these are real commands on real gear. A wrong command can disrupt a device, and on a serial console during greenfield setup there's often no prior working config to fall back to.

Safety gating (three tiers): read commands (show/ping/trace, and getting to enable) always run. Config CHANGES and device-DESTRUCTIVE commands (reload, reboot, write erase, erase/format, factory-reset) are gated by the Read-only toggle:

• Read-only mode ON (default) — holds BOTH: a change or destructive command is blocked with a note; nothing is sent.
• Read-only mode OFF — config changes run normally; a destructive command runs only after a loud on-screen warning, and the device's own "Proceed? [confirm]" is the final gate. Nothing destructive fires silently.

Your choice sticks: the toggle ships ON (safe by default), but whatever you last set is remembered across sessions — an advanced engineer who works with it OFF won't have to re-uncheck it every launch.

Copy text out: click-and-drag across the terminal to select, then Ctrl+C to copy the selection to the clipboard (right-click still pastes). Handy for lifting an interface name, MAC, or a line you typed in read-only mode over into config mode. If nothing is selected, Ctrl+C sends the normal interrupt to the device.

Config snippets ("Send all lines"): paste or import a block and push it line by line — it types each line, watches the device's reply, and STOPS at the first error (naming the line and why), so a bad line can't cascade. It runs EXACTLY what you paste — it never edits, reorders, or skips your commands; it only guards, warns, and reports. Prerequisites: be connected, at an enable/config prompt (type "en", then "conf t" — do that yourself), and with Read-only mode unchecked.

Generate rollback: after a push applies, "↩ Generate rollback" builds a DRAFT that undoes it — the inverse commands (shutdown⇄no shutdown, and "no …" to remove what a line added) — and loads it into the snippet box. Where it can't know the original value (a changed hostname, a set password, a rewritten description) it writes a "! MANUAL: …" comment naming the line instead of guessing. Nothing is sent: you review the draft, resolve the MANUAL lines, and push it yourself (so the same read-only/destructive gating applies). Cisco IOS style. It reverses the LAST push (or the lines that applied before a stop).

Passwords and passphrases you type are only ever held in memory for the session — SubnetSlinger never writes them to disk. If a command's own text carries a credential ("enable secret ...", "username admin secret ...", "snmp-server community ..."), the Activity log masks the value with asterisks so the log stays readable without storing the secret in plaintext.

Reading results: command output appears in the console. All three transports are a real persistent shell (SSH runs an actual PTY, not one-shot exec) — enable prompts, --More-- paging, and multi-step config wizards all carry state between commands the way a real terminal session does.