SPAN multiple destination ports on Cisco IOS device
It is possible to configure multiple destination (monitoring) ports within a SPAN session on most Cisco IOS platforms. When specifying the destination port, it is possible to indicate a series or range of interfaces using a command similar to the following:
monitor session 1 destination interface gigabitethernet0/0 - 1
This will cause Gi0/0 and Gi0/1 to become destination ports for this SPAN session.
Platforms that don't allow multiple destination ports will not allow this range syntax.
Note that a single destination port cannot belong to multiple SPAN sessions.
Links:
https://community.cisco.com/t5/switching/multiple-destination-span-configuration/td-p/2007780