Brocade switch ISL Trunking (2/64 Core and 4/256 Director)

[Sheldon Smith]

I have a number of Brocade SAN switch trunking questions. We are looking at setting up one (or more?) trunks between a SAN Switch 2/64 Core (12000) and a SAN Switch 4/256 (48000). Brocade says "all ports in a trunk need to be in a single 'port group'".
1) How does one tell how many ports and which ports are in a port group?
2) Are all port groups four ports in size?
3) Do the ports need to be adjacent in the port group?

4) Can anything else (hosts) be in a port group, or do all the ports become dedicated to the trunk regardless if an ISL cable is plugged in or not?

5) Can a given pair of switches have more than one trunk between them? If so, is there a limit?

Thanks in advance (and points after the fact) :)

[IBaltay]

Hi,
this is the Brocade FOS Admin Guide 6.10 link. The chapter 19 is Administering ISL Trunking:
http://www.brocade.com/education_services/docs/BCAF_docs/01_53_1000598_03_FOSAdminGuide_v610.pdf
standard trunking criteria:
1. direct connection between the participating switches
2. trunk ports must reside in the same port group
3. trunk ports must run at the same speed (2, 4, or 8Gbps)
4. trunk ports must be the same ISL type (L0=default)
5. Trunk ports must be E_ports or EX_Ports and F_ports if using the Access Gateway
6. All the ports must be adjacent
7. Both E_port or EX_port trunk can be up to 8 ports wide

[Sheldon Smith]

Thanks. Looking at the docs before, I'd missed points 6 and 7.

Still looking for an answer to "1": How does one tell which ports are in which port group? I've looked at all the commands, and haven't found one for that.

[IBaltay]

Hi,
the port group or a quad is a set of sequential ports, on some switches 4 ports, e.g
0-3,4-7,8-11
and Brocade platforms 300, 5100 and 5300 supports the 8 porst port groups,
e.g
0-7, 8-15, 16-23
up to the numbers of ports on the switch

[Amar_Joshi]

A port group is maximum possible ports in a trunk. For older 2GB ASICs it was restricted to 4 ports (e.g. 0,1,2 & 3) and with 4GB Condor ASICs it is increased to max of 8 ports in a trunk. Therefore with 2/64 you have a port group of 4 ports and in 4/256 you will have 8 ports.

Hope that answer your question about port group.

[Del_3]

Sheldon, Does the command "trunkshow" work for you for the answer to question 1?

[Bill Rothanburg · Accepted solution]

The port grouping depends upon the port blade installed.

In the case of the 12000, it only supports one type of port blade and it's every 4 ports on the same blade. (i.e. 0-3, 4-8, 9-12, and 13-15)

In the case of the 48000 with the FC2 and FC4 blades, every 8 ports on the same blade. (i.e. 0-7, 8-16, etc.)

Some of the blades shade the port number differently to help identify the port groups.


To use trunking, the ports on each switch have to be in the same group, but do not need to be consecutive. For management purposes, it helps to have them consecutive, but it's not required.

Hosts and storage, can be placed in the same port group as trunks, but it will limit your ability to expand a trunk later if needed. This is especially true with the 12000.

You can have multiple trunks to the same switch, or different switches within the fabric. Trunks just look like faster ISL's to the switch.

[Sheldon Smith]

When I was checking, the switches were running 4.2.2, and I don't recall "help" showing a "trunkshow" command in that version. The 12000s are updated to 5.0.5f now; I'll have my associate on-site check the results now.

Thanks to all who replied.