Difference between ISL and EISL trunk

[tarun.pahuja]

Folks,

Reading through documentation, i can not find out the differnece between ISL and EISL trunk, which is capable to carrying which traffic. Can they both carry Vsan and zoneset traffic? any information would be highly appreciated.

Thanks,

[tblancha]

The key is the vsan. A TE (with the T meaning trunking) carries vsan information so obviously, must be between two MDS switches. An E port is a normal extension port and does not have any vsan information across it. So, an E port can be between an MDS and another MDS or other vendor switch. Zone information would be exchanged on both an E and TE port but on a TE port, the zoning will be on a per-vsan basis.

[tblancha]

Let me add that an ISL link will make the ports to be E ports and a EISL link will be TE ports.

[tarun.pahuja]

I am slightly confused regrading your second post. How can we have ISL running over an E port, as E port is not a trunk port?

in your first port, you mean that a TE port with EISL will carry zone information for multiple Vsans, whereas E port will only have zoneset information for the VSAN that port belongs to, did i understand you correctly?

zone and zoneset information will be carried by both E and TE ports?

[inch]

Gday,

A E_Port (Expansion port) by will only carry zone and fabric information. A TE_port (Trunking expansion port) will also carry vsan information over it.

For example, if I wanted to merge vsan 100 on two of my directors i would do the following...

a) put the port I want to assign as the ISL into vsan 100 (vsan database; vsan 100 interface fc 1/1) on each switch

b) setup each interface as an E port (interface fc 1/1; switchport mode e )

If you wanted to create a link that joined vsan 100,101 and 102 you would need to do the following...

a) set the port up as an E port (interface fc 1/1; switchport mode e )

b) configure trunking for the vsans that you want carried over the isl (int fc 1/1; switchport trunk allowed vsan 100-102)

This will then carry information about each vsan over the link.

So in a short answer to your question... a E port will only carry zone/zoneset information for the vsan that it is in but a TE port will carry zone/zoneset information for each vsan that it is trunking.

Cheers

[tarun.pahuja]

thanks for your response. I think i am getting to understand this much better now ;-)

Will i be right to say that EISL link with carry Vsan traffic ( vsan database ) and ISL link will only carry VSAN information that port belongs to.

Thanks