AristaConfig927 downloads

Arista EOS Base / Day-0 Config

Day-zero configuration for Arista switches and routers: hostname, users, management interface, NTP, DNS, SNMP, eAPI, and ZTP disable.

↓ example.txt

What is it?

Arista EOS (Extensible Operating System) base config establishes Day-0 essentials: hostname, management VRF, SSH, eAPI, NTP, and syslog. EOS is Linux-based and uses a Cisco IOS-like CLI — most Cisco engineers can read EOS config immediately. A critical difference: Arista uses a dedicated Management VRF (typically 'MANAGEMENT') that isolates management plane traffic from the data plane. All management commands (NTP, syslog, DNS, eAPI) must specify 'vrf MANAGEMENT'. eAPI is Arista's REST API — it powers automation tools like Ansible, Terraform, and CloudVision.

When to use

·First-time setup of any Arista switch or router (7050, 7060, 7280, 7500 series)
·Standardizing Day-0 config before deploying in a data center fabric
·Before enabling BGP EVPN, MLAG, or OSPF — base config is the prerequisite for all

When NOT to use

·This is a prerequisite — all other Arista templates depend on base config being in place

How it compares

vs Cisco NX-OS base-configNX-OS requires 'feature' commands to enable protocols. EOS enables most features by default. Both use a management VRF. EOS eAPI is more powerful than NX-OS NX-API for automation.

vs Juniper base-configJunOS uses a commit model — changes stage before activating. EOS applies changes immediately (like Cisco IOS). EOS has 'configure session' for staged commits when needed.

Prerequisites

→Console access for initial setup before management IP is configured
→Management IP, subnet, and gateway decided before starting
→ZTP (Zero Touch Provisioning) must be disabled if manually configuring — 'ztp mode disable'
→NTP and DNS server IPs available — needed for certificate validation and eAPI

Config Generator

Hostname *

Domain Name

Admin Password *

Additional Users

Management Interface

Management IP (CIDR) *

Management Gateway *

Management VRF

Primary DNS

Secondary DNS

NTP Servers

Timezone

SNMP Community (RO)

SNMP Location

Syslog Host

Enable eAPI (HTTPS)?

Verification commands

show management ssh

Verify SSH is enabled and show active sessions

ExpectedShows SSH enabled, idle-timeout, and any active sessions

show ntp status

Verify NTP synchronization

ExpectedShows 'synchronized' with the reference NTP server IP and stratum

show management api http-commands

Verify eAPI is running and accessible

ExpectedShows protocol (HTTPS), port, and VRF. Status should be 'running'.

Debug commands

show logging last 50

Show the last 50 syslog messages

Common mistakes & fixes

SymptomCannot reach NTP/syslog/DNS from management interface

CauseCommands configured without specifying the management VRF

FixAll management-plane commands need 'vrf MANAGEMENT': 'ntp server vrf MANAGEMENT <ip>', 'logging vrf MANAGEMENT host <ip>'

SymptomeAPI not responding on HTTPS

CauseeAPI protocol not set to HTTPS or management SSH shutdown

FixVerify 'management api http-commands' has 'protocol https' and 'no shutdown'. Verify management VRF is specified.

SymptomZTP loop — device keeps rebooting to ZTP mode

CauseZTP not disabled and DHCP server providing a ZTP script

Fix'ztp mode disable' and 'ztp cancel' in EOS CLI. Add to startup-config to persist.

Further learning

Recommended books to go deeper on this topic.

CCNA 200-301 Official Cert Guide Library

Wendell Odom · Cisco Press · Best starting point for Cisco IOS fundamentals — CLI, interfaces, basic routing

Kindle ↗Hardcover ↗

CCNP Enterprise Core ENCOR 350-401 Official Cert Guide

Brad Edgeworth et al. · Cisco Press · For engineers ready to go deeper — routing, switching, security, automation