===== 🕒 NTP Configuration on Windows Server 2024 =====
 NTP Configuration on Aruba CX 6300 / 6400 (Houston, TX)
To configure the Windows Time Service (''w32time'') and synchronize with specific NTP servers, run the following commands **as Administrator** from PowerShell or CMD.

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==== 🌐 Example 1 — Global NTP Pool Servers ====

<code bash>
w32tm /config /manualpeerlist:"0.pool.ntp.org 1.pool.ntp.org 2.pool.ntp.org 3.pool.ntp.org" /syncfromflags:manual /reliable:yes /update
net stop w32time
net start w32time
w32tm /resync
</code>

*Use this option for general-purpose global synchronization.*

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==== ⚙️ Example 2 — Google and Cloudflare NTP Servers ====

<code bash>
w32tm /config /manualpeerlist:"time.google.com time.cloudflare.com" /syncfromflags:manual /reliable:yes /update
net stop w32time
net start w32time
w32tm /resync
</code>

*Use this option if you prefer high-availability public NTP providers.*

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==== 🔍 Verification ====

After applying the configuration, check synchronization status:

<code bash>
w32tm /query /status
w32tm /query /peers
</code>

**Expected results:**
  * ''Source'' → should show one of the configured NTP servers.  
  * ''Stratum'' → indicates synchronization level (lower = better).  
  * ''Last Successful Sync Time'' → confirms proper operation.

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==== 🧠 Notes ====
  * ''/manualpeerlist'' → Defines NTP servers (internal or external).  
  * ''/syncfromflags:manual'' → Forces use of the listed servers only.  
  * ''/reliable:yes'' → Marks this server as a reliable time source (for domain controllers).  
  * ''/update'' → Applies settings immediately.  
  * ''/resync'' → Forces an instant synchronization.



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===== 🕒 NTP Configuration on Aruba CX 6300 / 6400 (Houston, TX) =====

To configure the switch to synchronize its time using public NTP servers and apply the correct time zone for Houston (Central Time), run the following commands in **configuration mode**:

<code bash>
configure terminal

! Configure DNS servers for name resolution (required for NTP hostnames)
ip dns server-address 8.8.8.8
ip dns server-address 1.1.1.1

! Configure public NTP servers (requires DNS resolution)
ntp server 0.pool.ntp.org
ntp server 1.pool.ntp.org
ntp server 2.pool.ntp.org
ntp server 3.pool.ntp.org

! Enable NTP service
ntp enable

! Set time zone to Central Time (Houston, TX)
clock timezone america/chicago

exit
write memory
</code>

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==== 🔍 Verification ====

Check synchronization and clock status:

<code bash>
show ntp associations
show ntp status
show clock
</code>

**Expected output:**
  * ''show ntp associations'' → an asterisk (*) indicates the currently synchronized NTP source.  
  * ''show clock'' → displays local time adjusted to Central Time (CST/CDT).  
  * ''show ntp status'' → should report ''synchronized'' after a few minutes.

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==== 🧠 Notes ====
  * DNS servers (''dns server'') are **mandatory** if you use hostnames (e.g. ''pool.ntp.org''); otherwise, specify NTP servers by IP.  
  * ''america/chicago'' automatically handles daylight saving time.  
  * If using an internal NTP source (e.g. Windows Server), replace pool servers with its IP (e.g. ''ntp server 10.28.64.22'').  
  * NTP uses UDP port 123 — ensure it is allowed for outbound traffic.  
  * Save configuration permanently with ''write memory''.

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===== 🕒 NTP Configuration on Aruba 2930M (Houston, TX) =====

This configuration allows the Aruba 2930M switch (AOS-Switch) to keep accurate time using public NTP IP servers and the correct Central Time zone.

<code bash>
configure terminal

# Configure DNS servers (only if not already defined)
no ip dns server-address priority 1
no ip dns server-address priority 2
ip dns server-address priority 1 8.8.8.8
ip dns server-address priority 2 1.1.1.1

# Configure public NTP servers (IP addresses only)
ntp server 216.239.35.0       
ntp server 162.159.200.1       
ntp server 129.6.15.28         
ntp server 132.163.96.5      

# Set time zone to Central Time (Houston, TX)
time timezone -360

# Enable Daylight Saving Time for USA
time daylight-time-rule continental-us-and-canada

exit
write memory
</code>

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==== 🔍 Verification ====

Run the following commands to verify time synchronization:

<code bash>
show ntp status
show time
show clock
</code>

**Expected output:**
  * ''System time synchronized to NTP Server'' → indicates active NTP source.  
  * ''Time zone offset: -360'' → confirms Central Time (UTC−6).  
  * ''Daylight time rule: USA'' → daylight saving enabled.  

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==== 🧠 Notes ====
  * The 2930M does **not support NTP hostnames** — only IP addresses.  
  * If you have a local NTP server (e.g., Windows at 10.28.64.22), replace the public IPs with:
    <code>
    ntp server 10.28.64.22
    </code>
  * Use ''show ip dns'' to confirm DNS configuration.  
  * Save configuration permanently with ''write memory''.



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===== 🕒 NTP and DNS Configuration on Aruba 3810M (Houston, TX) =====

This configuration enables NTP synchronization, DNS resolution, and applies the correct Central Time zone (Houston, TX) with daylight saving rules for the continental U.S. and Canada.

<code bash>
configure terminal

! Enable NTP mode
timesync ntp
ntp enable

! Configure DNS servers for hostname resolution
ip dns server-address priority 1 8.8.8.8
ip dns server-address priority 2 1.1.1.1

! Configure NTP servers (can use hostnames if DNS is working)
ntp server 0.pool.ntp.org
ntp server 1.pool.ntp.org
ntp server 2.pool.ntp.org
ntp server 3.pool.ntp.org

! Set time zone to Central Time (UTC−6)
time timezone -360

! Enable daylight saving time for continental U.S. and Canada
time daylight-time-rule continental-us-and-canada

exit
write memory
</code>

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==== 🔍 Verification ====

Verify NTP synchronization, DNS status, and system time:

<code bash>
show ntp status
show ntp associations
show ip dns
show time
show clock
</code>

**Expected results:**
  * ''System time synchronized to NTP Server …'' → indicates active synchronization.  
  * ''Time zone offset: -360'' → confirms Central Time.  
  * ''Daylight time rule: continental-us-and-canada'' → DST adjustment active.  
  * ''DNS server(s): 8.8.8.8, 1.1.1.1'' → confirms DNS configuration.

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==== 🧠 Notes ====
  * Aruba 3810M supports **FQDN or IP** for NTP servers — DNS must be reachable.  
  * To use an internal NTP source (e.g. Windows Server), replace pool servers with:
    <code>
    ntp server 10.28.64.22
    </code>
  * If DNS is unreachable, use IP addresses directly for NTP.  
  * NTP uses UDP port 123; confirm outbound reachability.  
  * Save configuration permanently with ''write memory''.


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===== 🕒 SNTP and DNS — Dell EMC N3048P (DNOS 6.5.3.6, Houston, TX) =====

Validated configuration for accurate timekeeping with SNTP (unicast), DNS resolvers, Central Time (UTC−6) and U.S. DST.

<code bash>
! Already applied (from running-config):
sntp unicast client enable
sntp server 216.239.35.0
sntp server 162.159.200.1
sntp server 129.6.15.28
sntp server 132.163.96.5
clock summer-time recurring USA
clock timezone -6 minutes 0
ip name-server "8.8.8.8"
ip name-server "1.1.1.1"

exit
write memory
</code>

==== 🔍 Verification ====
<code bash>
show sntp
show clock
show running-config | include sntp|clock|name-server
</code>

**Expected:**
  * ''SNTP Client Mode: Unicast'' and servers ''Reachable''  
  * ''Clock timezone offset: -6'' and ''DST: USA (active when applicable)''  
  * Last sync time updates periodically (UDP/123 reachable)

==== 🧠 Notes ====
  * DNOS 6 in N3000 uses **SNTP** (no full NTP).  
  * If DNS is down, keep servers by **IP** (as configured).  
  * Ensure outbound **UDP/123** is allowed from the chosen source-interface.  
  * Persist with ''write memory'' after any change.



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===== 🕒 NTP and DNS Configuration on Aruba 7220 (AOS 8.12, Houston, TX) =====

Use IANA timezone names. For Houston, use ''America/Chicago'' (DST automático).

<code bash>
configure terminal

! DNS (opcional, para resolver FQDN)
ip name-server 8.8.8.8
ip name-server 1.1.1.1

! NTP servers (FQDN soportado si hay DNS)
ntp server 0.pool.ntp.org
ntp server 1.pool.ntp.org
ntp server 2.pool.ntp.org
ntp server 3.pool.ntp.org

! Zona horaria IANA (Houston)
clock timezone America/Chicago

end
write memory
</code>

==== 🔍 Verificación ====
<code bash>
show ntp servers
show ntp status
show clock
</code>

**Esperado:**
  * Uno de los NTP marcado como peer activo.
  * ''show clock'' mostrando hora local con ''CDT/CST'' según corresponda (DST automático).

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===== 🕒 NTP and DNS Configuration on Arista 7050QX (EOS 4.13.x, Houston, TX) =====

This configuration enables DNS resolution, adds public NTP servers, and applies the Central Time zone.

<code bash>
configure terminal

ip name-server 8.8.8.8
ip name-server 1.1.1.1

ntp server 0.pool.ntp.org
ntp server 1.pool.ntp.org
ntp server 2.pool.ntp.org
ntp server 3.pool.ntp.org

clock timezone US/Central

end
write memory
</code>

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==== 🔍 Verification ====
<code bash>
show ntp status
show ntp associations
show clock
</code>
Expected:
  * One server selected as the system peer.
  * ''show clock'' shows local time with timezone ''US/Central''.

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==== 🧠 Notes ====
  * ''ip name-server'' configures DNS resolvers on EOS. :contentReference[oaicite:0]{index=0}  
  * ''ntp server <ip|fqdn>'' adds time sources; EOS NTP is enabled by default. Use ''iburst'' if desired for faster initial sync. :contentReference[oaicite:1]{index=1}  
  * Time zone labels accept **IANA/alias names** like **''US/Central''** or **''America/Chicago''** (''clock timezone ?'' lists options). :contentReference[oaicite:2]{index=2}  
  * To force the source address, use **''ntp local-interface <intf>''** (e.g., **Management1** or a VLAN SVI). :contentReference[oaicite:3]{index=3}  
  * If NTP must traverse **VRF MGMT**, append **''vrf MGMT''** to each server line. :contentReference[oaicite:4]{index=4}


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===== 🕒 NTP and DNS on Cisco Catalyst 9500 (IOS XE 17.12) — Houston, TX =====

DNS + NTP con zona horaria Central (CST/CDT). ''ip domain-lookup'' no es requerido en esta versión.

<code bash>
conf t
ip name-server 8.8.8.8
ip name-server 1.1.1.1

! NTP servers (FQDN soportado)
ntp server 0.pool.ntp.org
ntp server 1.pool.ntp.org
ntp server 2.pool.ntp.org
ntp server 3.pool.ntp.org

! (Opcional) Fuente de NTP para dirección estable
ntp source Loopback0

! Zona horaria Houston (Central) + DST EE.UU.
clock timezone CST -6
clock summer-time CDT recurring 2 Sun Mar 2:00 1 Sun Nov 2:00

end
write memory
</code>

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==== 🔁 (Opcional) Enviar NTP por el VRF de management ====
Si tu salida a Internet va por **Mgmt-vrf**, usa:

<code bash>
conf t
ntp source Loopback0
ntp server vrf Mgmt-vrf 0.pool.ntp.org
ntp server vrf Mgmt-vrf 1.pool.ntp.org
ntp server vrf Mgmt-vrf 2.pool.ntp.org
ntp server vrf Mgmt-vrf 3.pool.ntp.org
end
write memory
</code>

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==== 🔍 Verificación ====
<code bash>
show hosts                      ! valida resolución DNS
ping 0.pool.ntp.org             ! (o ping vrf Mgmt-vrf 0.pool.ntp.org)
show ntp associations
show ntp status
show clock detail
show run | i name-server|ntp|clock
</code>

**Esperado:**
  * Un servidor con ''*'' como **system peer** en ''show ntp associations''.
  * ''show clock detail'' mostrando CST/CDT y estado de DST.
  * DNS resolviendo (''show hosts'').

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==== 🧠 Notas ====
  * Si algún FQDN no resuelve, prueba primero con **IP** para descartar DNS.
  * Asegura salida **UDP/123** desde la interfaz/VRF usada por NTP.
  * Puedes marcar un servidor como preferido:  
    <code>ntp server 0.pool.ntp.org prefer</code>

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