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Cisco IOS driver

The cisco_ios driver presents a Cisco IOS personality over SSH: a greeting, a host> / host# prompt, enable mode, and a set of show commands answered convincingly. It is the default driver and the one most NCM tooling will exercise.

Session flow

Section titled “Session flow”

On connect the device emits a greeting and the user-mode prompt:

<hostname> line 0 is now available


<hostname>>

A typical collection session: set the terminal length, enter enable mode, then pull config.

terminal length 0
enable
Password: enable123
show running-config
exit          ← leaves enable mode
exit          ← closes the session

enable prompts for the enable password; a correct password moves the prompt from > to #. A wrong one prints % Access denied.

Supported commands

Section titled “Supported commands”
Command Behaviour
terminal length 0 Silent acknowledgement (disables paging)
terminal pager 0 Silent acknowledgement
enable Prompts for the enable password; enters enable mode
show version Canned IOS 15.x version block with the device’s hostname and serial
show running-config The full generated config, streamed zero-copy from mmap
show startup-config The same bytes as show running-config
show inventory Canned inventory; chassis SN matches show version’s serial
exit / quit / logout / end Leave enable mode, or close the session

Anything else returns % Invalid input detected at '^' marker., unless a command file matches it. Command files are checked first, so they can also override the commands above.

Prefix matching

Section titled “Prefix matching”

Like real IOS, commands resolve by per-token unique prefix: sh ver → show version, sh run → show running-config. Two rules make this predictable:

  • Exact matches always win. end resolves as an exit alias even though it shares its first two letters with enable.
  • Genuinely ambiguous prefixes are rejected. en is a prefix of both enable and end, so it returns % Ambiguous command rather than guessing. Type the distinguishing character (ena… or end).

Aliases that collapse to the same action (exit/quit/logout/end all close or drop a mode) are not treated as ambiguous.

Metrics

Section titled “Metrics”

Each resolved command is recorded under rcfgsim_command_duration_seconds{command="..."}. The Cisco driver’s label values are the Cmd* names: CmdShowRunningConfig, CmdEnable, CmdShowVersion, CmdUnknown, CmdAmbiguous, and the rest. See the metrics reference.

Arista EOS on cisco_ios

Section titled “Arista EOS on cisco_ios”

rConfig-sim has no separate EOS driver. EOS’s CLI is IOS-shaped: host> becomes host# after enable, and terminal length 0 turns paging off, so an EOS device runs on cisco_ios (manifest template = cisco_ios, vendor = Arista). EOS-specific output, such as show lldp neighbors detail in EOS format or an EOS show version, comes from command files. The mesh-campus scenario has a worked EOS device, core-01.

In a configuration manager, an IOS SSH template with enable mode works for these devices.

SSH authentication

Section titled “SSH authentication”

cisco_ios returns RequiresSSHAuth() == true — it authenticates at the SSH transport layer. Under --ssh-auth=driver that means Cisco devices challenge for a password while Ciena devices don’t.