Contents

Introduction

Prerequisites

Requirements

Components Used

Background Information

Check Ethernet Cisco Discovery Protocol (CDP) Neighbors and FC Neighbors

Related Information

Introduction

This document describes how to check upstream Fiber Channel (FC) Storage Area Network (SAN) Switch connected to a Unified Computing System (UCS) Fabric Interconnect (FI).

Prerequisites

Requirements

There are no specific requirements for this document.

Components Used

The information in this document is based on these software and hardware versions:

- UCS Fabric Interconnects and UCS Manager

- Cisco MDS or Nexus Storage Switch

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Background Information

It is usually quite easy to determine theIP address of an upstream ethernet switchconnected to a UCS Fabric Interconnect with the use of the commandshow cdp neighborsfrom the nxos prompt. However, most of us experience difficulties to figure out similar information for an upstream FC switch connected to a UCS Fabric Interconnect.

Check Ethernet Cisco Discovery Protocol (CDP) Neighbors and FC Neighbors

An example from the lab:

WW-SV-115-A-A(nxos)# show cdp neighbors

Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge

S - Switch, H - Host, I - IGMP, r - Repeater,

V - VoIP-Phone, D - Remotely-Managed-Device,

s - Supports-STP-Dispute

Device-ID             Local Intrfce Hldtme Capability  Platform      Port ID

BGL-SV-CAT6K-01        mgmt0         179    R S I     WS-C6503-E    Gig2/18

BGL-SV-N5548UP-01-14(SSI15430M56)

Eth1/9        161    S I s     N5K-C5548UP   Eth1/16

BGL-SV-N5548UP-02-15(SSI15430MAW)

Eth1/11       153    S I s     N5K-C5548UP   Eth1/17

If the Fabric Interconnect FC is configured forSwitching Mode, you can use the commandshow topology in orderto fetch the required information.

If the Fabric Interconnect FC is configured forEnd Host Mode, you can use the commandshow npv internal info external-interface all in orderto fetch the required information.

WW-SV-115-A-A(nxos)# show npv internal info external-interface all

External Interface Info:

========================

Interface Information:

ifindex: fc1/32, Port VSAN: 200, Internal FLOGI VSAN: 200, fcid: 0xd10241              < FABRIC INTERCONNECT PORT & ITS FCID

Internal FLOGI Done: True, In Progress: False

FSM current state: NPIVP_EXT_IF_ST_UP

fabric mgmt addr: 10.76.78.15                                                                                     <UPSTREAM SWITCH IP ADDRESS

fabric pwwn: 20:43:54:7f:ee:e2:ac:80, fabric nwwn: 20:c8:54:7f:ee:e2:ac:81              <UPSTREAM SWITCH WWN

my pwwn: 20:20:8c:60:4f:4f:4f:c0, my nwwn: 20:c8:8c:60:4f:4f:4f:c1                          <FABRIC INTERCONNECT WWN

fcf_mac: 8c60:4f4f:4fe7

Pinned Server Intf Count: -3

------------ OUTPUT TRUNCATED ------------

WW-SV-115-A-A(nxos)# show interface fc 1/32

fc1/32 is up

Hardware is Fibre Channel, SFP is short wave laser w/o OFC (SN)

Port WWN is 20:20:8c:60:4f:4f:4f:c0                                                                          <FABRIC INTERCONNECT PWWN (re-verified)

Admin port mode is NP, trunk mode is off

------------ OUTPUT TRUNCATED ------------

You get theIP Address of the upstream FC SAN Switch. However, this does not reveal the port to which the Fabric Interconnect is connected. In order to find the port information, you need to login to the upstream FC SAN Switch and check the FLOGI database.

BGL-SV-N5548UP-02-15# show flogi database | include 20:20:8c:60:4f:4f:4f:c0

--------------------------------------------------------------------------------

INTERFACE        VSAN    FCID           PORT NAME               NODE NAME

--------------------------------------------------------------------------------

fc2/3            200   0xd10241  20:20:8c:60:4f:4f:4f:c0 20:c8:8c:60:4f:4f:4f:c1                <UPSTREAM SWITCH PORT AND FABRIC INTERCONNECT FCID & WWN

Thus, you can conclude that the Fabric Interconnect port fc1/32 with PWWN 20:20:8c:60:4f:4f:4f:c0 and FCID 0xd10241 has been learned on upstream FC SAN Switch with IP Address 10.76.78.15 on port fc2/3.

UCS Manager GUI can also be used to figure out the information related to the IP Address of the upstream switches.

Firstly, Information Policy needs to be Enabled.

Step 1. In the Navigation pane, click theEquipmenttab.

Step 2. In theEquipmenttab, click theEquipmentnode.

Step 3.In the Work pane, click thePoliciestab.

Step 4.Click theGlobal Policiessubtab.

Step 5.In theInfo Policyarea, selectEnabled.

Step 6.ClickSaveChanges.

Then, you need to navigate to the Neighbors tab for the respective Fabric Interconnect.

Step 1.In the Navigation pane, click theEquipmenttab.

Step 2.In theEquipmenttab, expandEquipment>Fabric Interconnects.

Step 3. Click the fabric interconnect for which you want to view the SAN neighbors.

Step 4.In the Work pane, click theNeighborstab.

Step 5.Click theSANsubtab as shown in the image.

In order to check the same information (after you enable the policy) from CLI.

WW-SV-115-A# scope fabric-interconnect a|b

WW-SV-115-A /fabric-interconnect# show san-neighbors

Related Information

- Cisco Unified Computing System Ethernet Switching Modes

- Technical Support & Documentation - Cisco Systems