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--- windows:windows_time_service_ntp [2025/10/07 12:07] – [🕒 NTP and DNS Configuration on Cisco Catalyst 9500 (IOS XE 17.12)] aperez
+++ windows:windows_time_service_ntp [2025/10/07 12:08] (current) – aperez
@@ Line 376: / Line 376: @@
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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.
-===== 🕒 NTP and DNS Configuration on Cisco Catalyst 9500 (IOS XE 17.12) =====
-This configuration enables DNS resolution, adds public NTP servers, and applies Central Time (Houston) with U.S. daylight saving.
 <code bash>
@@ Line 387: / Line 385: @@
 ip name-server 1.1.1.1
+! NTP servers (FQDN soportado)
 ntp server 0.pool.ntp.org
 ntp server 1.pool.ntp.org
@@ Line 392: / Line 391: @@
 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
@@ Line 401: / Line 404: @@
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-==== 🔁 (Optional) Use Management VRF and set NTP source ====
+==== 🔁 (Opcional) Enviar NTP por el VRF de management ====
-If NTP must go out the management path, bind it to **Mgmt-vrf** and pick a stable source interface (e.g., Loopback0 or a SVI).
+Si tu salida a Internet va por **Mgmt-vrf**, usa:
 <code bash>
 conf t
-! choose a stable source address for NTP packets
 ntp source Loopback0
-! send NTP via the management VRF
 ntp server vrf Mgmt-vrf 0.pool.ntp.org
 ntp server vrf Mgmt-vrf 1.pool.ntp.org
@@ Line 420: / Line 420: @@
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-==== 🔍 Verification ====
+==== 🔍 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 ntp|name-server|clock
+show run | i name-server|ntp|clock
 </code>
-**Expected:**
+**Esperado:**
-  * One server marked as the **system peer** in ''show ntp associations''.
+  * Un servidor con ''*'' como **system peer** en ''show ntp associations''.
-  * ''show clock detail'' shows local time with CST/CDT and DST state.
+  * ''show clock detail'' mostrando CST/CDT y estado de DST.
-  * DNS servers listed under ''name-server''.
+  * DNS resolviendo (''show hosts'').
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-==== 🧠 Notes ====
+==== 🧠 Notas ====
-  * Cisco IOS XE acepta **FQDN o IP** en ''ntp server''.
+  * Si algún FQDN no resuelve, prueba primero con **IP** para descartar DNS.
-  * Si usas servidores internos, reemplaza los del pool por tu host (ej.:
+  * Asegura salida **UDP/123** desde la interfaz/VRF usada por NTP.
-    <code>conf t
+  * Puedes marcar un servidor como preferido:
-no ntp server 0.pool.ntp.org
+    <code>ntp server 0.pool.ntp.org prefer</code>
-no ntp server 1.pool.ntp.org
-no ntp server 2.pool.ntp.org
-no ntp server 3.pool.ntp.org
-ntp server 10.28.64.22 prefer
-end
-write memory</code> )
-  * Asegura salida **UDP/123** desde la interfaz origen/VRF usados.
-  * ''clock summer-time ... recurring'' aplica el cambio a DST automáticamente (1 h).
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