Arista

Arista DCS-7504 Password Recovery

Step-by-step password recovery for the Arista DCS-7504 (7150/7280/7500 (EOS)). Console access required.

Overview

This guide provides step-by-step instructions for resetting lost or forgotten administrative passwords on enterprise networking hardware. Follow the procedure below carefully to regain access while preserving your device configuration.

Prerequisites

Before proceeding with password recovery, ensure you have a console cable, terminal emulation software configured to 9600 baud, and physical access to the device.

Step 1: Establish Console Connection

Connect your terminal cable to the console port of the device and open your serial terminal session.

Step 2: Interrupt the Boot Sequence

Power cycle the hardware and issue a Break key sequence during initial system startup to enter ROMMON mode.

Step 3: Reset Password & Configuration

Bypass startup configuration loading, boot into system software, set your new credentials, and save changes back to non-volatile memory.

Overview

This procedure recovers administrator access to the Arista DCS-7504 running Arista EOS when the admin password is lost. Arista's Aboot (Arista boot loader) supports a single-user boot that drops to a root shell where the admin password can be reset — the configuration is preserved.

Prerequisites

Console cable (RJ-45 serial) with a terminal session at 115200 baud, 8N1 (Arista switches use 115200). Physical or remote power access to reboot the switch.

Recovery Procedure — Aboot Single-User Mode

Connect the console cable and open a terminal session at 115200 baud, 8N1.
Reboot the switch (power-cycle or reload if you have access).
During boot, when the Aboot prompt appears (or the message "Press Ctrl-C to enter Aboot" shows), press Ctrl+C to enter Aboot. You get the Aboot> prompt.
Boot into single-user mode: boot -s (on newer EOS) — or if -s is not supported, boot normally and interrupt the EOS boot to single-user via the kernel parameter.
The switch drops to a root shell (single-user mode).
Mount the filesystem read-write if needed: mount -o remount,rw /
Reset the admin password: passwd admin — enter the new password twice.
Reboot: reboot (or boot from Aboot). Log in as admin with the new password.

Recovery Procedure — Aboot Password Recovery (alternative)

Enter Aboot as above (Ctrl+C at the Aboot prompt).
Use the Aboot command to reset the admin password: recovery (on EOS versions that support it) or boot default to boot with a clean config.
If recovery is unavailable, boot with the config-bypass kernel flag and reset the password from the shell as above.

Important Notes

Arista consoles use 115200 baud — 9600 produces garbage on screen.
Single-user mode preserves the configuration — only the admin password is reset.
The default Arista admin account is admin; the factory default password is set at initial setup (the serial number-based default on some builds).
On EOS with a configured Aboot password, entering Aboot requires that password — contact Arista TAC with proof of ownership if it is lost.

Protecting Your Configuration

Before recovery, back up the config: copy running-config flash:/backup.cfg or export via show running-config. After recovery, verify and re-save with write memory.