trunking between 2 switches and transporting vsan

[jmcgrady1]

I have a topology that will look like:  san1 - switch1 - switch2 - san2.

The SANs are HPE Alletra using FC. The Alletra requires its san to san replication ports (RCFC) to use a different zone from its host to SAN ports.  That seems straightforward.

I am using MDS 9132T switches.

However, where i want to connect the 2 switches together, how would i configure those ports to carry all zones?

[Jason Mooney]

@jmcgrady1 
Could you help me better understand the topology that you are trying to achieve?  
Are you trying to combine two fabrics into one?  If so, this is a bad idea.  SANs are built with two fabrics for redundancy.

   Fabric A                        Fabric B  
┌───────────┐                   ┌───────────┐
│           │  ◄─────────────   │           │
│ MDS 9132T │  ─────────────►   │ MDS 9132T │
│           │                   │           │
└───────────┘                   └───────────┘

 Are you trying to Extend Fabrics between distances either local or remote sites?
I'm not familiar with Alletera, but many storage vendors that perform FC replication often recommend VSAN isolation.  In the scenario below you could have multiple VSANs on each fabric.  One for replication, and one for your host (initiators) and storage (targets).  When you setup a port-channel between a pair of switches you specify which VSANs are trunked.  For more information about port-channels and trunking you can follow this link: Configuring Port Channels 

    Site 1                          Site 2   
   Fabric A                        Fabric A  
┌───────────┐                   ┌───────────┐
│           │  ◄─────────────   │           │
│ MDS 9132T │  ─────────────►   │ MDS 9132T │
│           │                   │           │
└───────────┘                   └───────────┘
                                             
                                             
    Site 1                          Site 2   
   Fabric B                        Fabric B  
┌───────────┐                   ┌───────────┐
│           │  ◄─────────────   │           │
│ MDS 9132T │  ─────────────►   │ MDS 9132T │
│           │                   │           │
└───────────┘                   └───────────┘

[jmcgrady1]

i am wanting to extend the fabric across 2 switches in separate locations.  I have since been told i must set the trunk port to 'switchport mode E'

[Jason Mooney]

Extending a Fibre Channel Fabric Between MDS 9132T Switches

Thanks for the clarification. Since you're extending a Fibre Channel (FC) fabric between two MDS 9132T switches located at separate sites, you're setting up an Inter-Switch Link (ISL).

How to Configure the ISL to Carry All Zones

To carry all zones and VSANs between the switches, configure the connecting ports as E ports using:

switchport mode E

If you're using multiple VSANs (e.g., one for RCFC replication and one for host/target traffic), the ISL will automatically trunk them as long as both ends allow the same VSANs.

Recommended: Use a Port-Channel for Redundancy

Grouping multiple E ports into a port-channel improves resilience and reduces disruptions:

interface port-channel 10
  switchport
  switchport mode E
  vsan trunk allowed all

interface fc1/1
  switchport
  channel-group 10

interface fc1/2
  switchport
  channel-group 10

SFP Module Options for Native FC

For site-to-site native Fibre Channel, use longwave optics that support your required distances:

Speed	Part Number	Max Distance	Connector Type
32G FC	DS-SFP-F32G-LW=	10 km over single-mode fiber (SMF)	LC duplex
16G FC	DS-SFP-FC16G-LW=	10 km over SMF	LC duplex
8G FC	DS-SFP-FC8G-LW=	10 km over SMF	LC duplex

Note: Fibre Channel is a lossless protocol. Signal quality is critical — dropped frames due to poor optics, dirty connectors, or marginal links can result in I/O errors.  For more information about Transceivers and Requirements Cisco MDS 9000 Family pluggable transceivers documentation.

Alternative: FCIP Using MDS 9220i

As an alternative to native FC, you can use an MDS 9220i to tunnel FC over IP (FCIP). This method is often used for longer distances or less reliable links.

Feature	Native FC ISL	FCIP (MDS 9220i)
Pros	- Low latency - Simple config if fiber is clean - No additional hardware needed	- Resilient to network loss - TCP retransmits dropped frames - Easier to troubleshoot via IP tools
Cons	- No retransmission - Sensitive to dirty/unstable fiber - Requires dedicated clean fiber	- Requires 9220i hardware - Higher complexity - TCP/IP adds latency and overhead

Tip: If using FCIP, use dedicated links or VLANs for storage traffic. Avoid mixing with regular corporate IP traffic to ensure frame ordering and latency guarantees.

I hope this provided some insight for you.