– Not to be confused with ISL trunking (port aggregation)
• Enhanced ISL (EISL):
– Link created by two connected TE_Ports – Superset of ISL functionality
– Carries per-VSAN control protocol information (e.g. zoning updates)
TE_Port EISL
TE_Port
E_Ports
ISL
Cisco switch Cisco switch
Other vendor’s switch
Trunking E_Ports (TE_Ports) have the following characteristics:
• TE_Ports can pass tagged frames belonging to multiple VSANs. • TE_Ports are only supported by Cisco MDS 9000 switches. • By default, TE_Ports can pass all VSAN traffic (1-4093). The passing of traffic for specific VSANs can be disabled.
• By default, E-Ports are assigned as part of VSAN 1. • TE_Ports allow for the segregation of SAN traffic and should not be confused with port aggregation (referred to by some vendors as trunking).
Enhanced ISLs (EISLs) are ISLs that connect two TE_Ports:
• An EISL is created when two TE_Ports are connected. • EISLs offer a superset of ISL functionality, • EISLs carry per-VSAN control protocol information.