---
title: Nexus Upgrade port Breakout
description: 
published: true
date: 2026-02-20T19:24:28.054Z
tags: 
editor: markdown
dateCreated: 2026-02-19T20:55:53.800Z
---

# Nexus 9300 Port Migration — Old to New Architecture

## Switch 1 — AT1EU-NEXUS-1

| Old Port | Description | New Port | Device | Device Port |
|---|---|---|---|---|
| Ethernet1/2 | Trunk FAS 2750 | — | Catalyst | T1/1/3 |
| Ethernet1/3 | Trunk FAS 2750 | — | Catalyst | T1/1/4 |
| Ethernet1/9 | Trunk A70-A | Ethernet1/5/1 | A70 | — |
| Ethernet1/10 | Trunk A70-A | Ethernet1/5/3 | A70 | — |
| Ethernet1/11 | Trunk A70-B | Ethernet1/5/2 | A70 | — |
| Ethernet1/12 | Trunk A70-B | Ethernet1/5/4 | A70 | — |
| Ethernet1/17 | Trunk 500e-X1 | Ethernet1/26 (10G) | Firewall | X1 |
| Ethernet1/23 | Access L3 HLCI JAVELIN (Allow STP-BPDU) | — | Catalyst | T1/1/5 |
| Ethernet1/24 | Access L3 HLCI ROCK(L3)MLS (Allow STP-BPDU) | — | Catalyst | T1/1/6 |
| Ethernet1/25 | Trunk 6554-1:25 | Ethernet1/1/1 | UCS 6554-1 | 1/25 |
| Ethernet1/26 | Trunk 6554-1:26 | Ethernet1/1/3 | UCS 6554-1 | 1/26 |
| Ethernet1/27 | Trunk 6554-2:27 | Ethernet1/1/2 | UCS 6554-2 | 1/27 |
| Ethernet1/28 | Trunk 6554-2:28 | Ethernet1/1/4 | UCS 6554-2 | 1/28 |
| Ethernet1/45 | Trunk 9300 | Ethernet1/24 (10G) | Catalyst 9300 | T1/1/1 |
| Ethernet1/46 | Trunk 9300 | Ethernet1/25 (10G) | Catalyst 9300 | T1/1/2 |
| Ethernet1/47 | Trunk Peer-Link (Allow STP) | Ethernet1/27 | NEXUS-2 Peer | — |
| Ethernet1/48 | Trunk Peer-Link (Allow STP) | Ethernet1/28 | NEXUS-2 Peer | — |

> **Legend:** `—` in New Port column indicates the connection moves to the listed Device/Port with no renumbered Nexus port. 25G breakout ports (1/1/x and 1/5/x) are carved from 100G uplinks via `interface breakout module 1 port X map 25g-4x`.

---

## Switch 2 — AT1EU-NEXUS-2

| Old Port | Description | New Port | Device | Device Port |
|---|---|---|---|---|
| Ethernet1/2 | Trunk FAS 2750-A | — | Catalyst | T2/1/3 |
| Ethernet1/3 | Trunk FAS 2750-B | — | Catalyst | T2/1/4 |
| Ethernet1/9 | Trunk A70-A | Ethernet1/5/1 | A70 | — |
| Ethernet1/10 | Trunk A70-A | Ethernet1/5/3 | A70 | — |
| Ethernet1/11 | Trunk A70-B | Ethernet1/5/2 | A70 | — |
| Ethernet1/12 | Trunk A70-B | Ethernet1/5/4 | A70 | — |
| Ethernet1/16 | Access NetApp XFER | — | Catalyst | T2/1/7 |
| Ethernet1/17 | Trunk 500e-X1 | Ethernet1/26 (10G) | Firewall | X1 |
| Ethernet1/22 | Access L4 HLCI JAVELIN (Allow STP-BPDU) | — | Catalyst | T2/1/5 |
| Ethernet1/24 | Access L4 HLCI ROCK(L4)MLS (Allow STP-BPDU) | — | Catalyst | 21/1/6 |
| Ethernet1/25 | Trunk 6554-2:25 | Ethernet1/1/1 | UCS 6554-2 | 1/25 |
| Ethernet1/26 | Trunk 6554-2:26 | Ethernet1/1/3 | UCS 6554-2 | 1/26 |
| Ethernet1/27 | Trunk 6554-1:27 | Ethernet1/1/2 | UCS 6554-1 | 1/27 |
| Ethernet1/28 | Trunk 6554-1:28 | Ethernet1/1/4 | UCS 6554-1 | 1/28 |
| Ethernet1/45 | Trunk 9300 | Ethernet1/24 (10G) | Catalyst 9300 | T1/1/2 |
| Ethernet1/46 | Trunk 9300 | Ethernet1/25 (10G) | Catalyst 9300 | T2/1/2 |
| Ethernet1/47 | Trunk Peer-Link (Allow STP) | Ethernet1/27 | NEXUS-1 Peer | — |
| Ethernet1/48 | Trunk Peer-Link (Allow STP) | Ethernet1/28 | NEXUS-1 Peer | — |

> **Legend:** `—` in New Port column indicates the connection moves to the listed Device/Port with no renumbered Nexus port. 25G breakout ports (1/1/x and 1/5/x) are carved from 100G uplinks via `interface breakout module 1 port X map 25g-4x`.

---

## Summary of Changes

| Change Type | Details |
|---|---|
| **Breakout (100G → 4x25G)** | Ports 1, 5 on both switches broken out to 25G sub-interfaces for UCS FI and A70 storage connectivity |
| **UCS 6554 FI connections** | Old Ethernet1/25–1/28 (fixed 1/x ports) → New Ethernet1/1/1–1/1/4 (breakout sub-ports) |
| **A70 Storage connections** | Old Ethernet1/9–1/12 (fixed 1/x ports) → New Ethernet1/5/1–1/5/4 (breakout sub-ports) |
| **9300 Uplinks** | Old Ethernet1/45–1/46 → New Ethernet1/24–1/25 (10G, connecting to Catalyst T1/1/1–T1/1/2) |
| **500e Firewall** | Old Ethernet1/17 → New Ethernet1/26 (10G, firewall X1) |
| **Peer-Link** | Old Ethernet1/47–1/48 → New Ethernet1/27–1/28 (both switches) |
| **Moved to Catalyst** | FAS 2750, HLCI JAVELIN, HLCI ROCK, and (Sw2 only) NetApp XFER ports migrated off the Nexus to a downstream Catalyst switch |

