Since VSP 8.2 release a new Segmented Management Interface has been introduced which provides a more unambiguous management interface and avoids asymmetric routing problems when OOB and VLAN us used. There are three type of mgmt interface which are OOB, CLIP and VLAN. Existing switches pre 8.2 can be configured to migrate one of their management interface types to a SMI (migrate-to-mgmt command present in 7.1.3, 8.0.1 and 8.1.0).
Be aware that after the upgrade the GRT interface will disappear and if a VLAN IP was used for management on a L3 BEB or L3 router then traffic inbound on a different VLAN will not reach the mgmt VLAN. For this type of switch it is recommended to use a CLIP for management.
The slides below explain the reason for the change and the recommendations to follow when upgrading to 8.2 or higher.
It might be simpler to assign a new CLIP for management purposes and keep existing CLIP used by ISIS Source IP or as Router ID for OSPF and/or BGP. If you do this consider external servers that have discovered the switch using a different IP and also external RADIUS servers which are configured with the previous IP address.
After the upgrade ISIS Source IP is no longer necessary but is recommended if IP shortcuts are used. If the original CLIP is used for management it will disappear and not be available for ISIS Source IP so a new CLIP should be considered.
Decide which VRF to use for management and which type of interface (OOB, CLIP or VLAN) based on L3 BEB, L3 Router, L2 BEB or L2 Switch.