Brocade SAN switch FOS v7.0.0 and later
No, prior to FOS v7.0.0, Brocade FOS provides interop Mode 1 to interoperates with Brocade and McData and Cisco switches
Brocade:admin> interopmode 1 <==== Set interop mode on
The command was implemented to support the McDATA switches after Brocade bought McData, and the command had been deprecated starting from FOS 7.0.0 when the McDATA devices went into End of Support.
After FOS v7.0.0, the Brocade SAN switches are not interoperable with Cisco SAN switches. the Cisco devices can only join the Brocade Fabric as NPIV devices.