HP Cisco MDS 9120 Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Rel - Page 32

Limitations and Restrictions Send documentation comments to [email protected] • If port 80 on the switch is blocked and you are using VPN, Fabric Manager cannot detect NAT addresses. The timeout for URL connections is set for 500ms. MTU Size Limitation The Cisco MDS 9216i switch and MPS-14/2 module do not support an MTU size greater than 8000 bytes. An attempt to set the MTU size greater than 8000 bytes will result in an error. As a workaround, reset the value of the MTU size (576 to 8000 bytes) and issue the no shutdown command on the interface for normal operation. Reconfiguring SSM Ports Starting with Cisco MDS SAN-OS Release 3.0(1), the SSM front panel ports can no longer be configured in auto mode, which is the default for releases prior to Release 3.1(1). For instructions about how to modify the configuration of the ports before upgrading to SAN-OS Release 3.1(3a), see the "Reconfiguring SSM Ports Before Upgrading to SAN-OS Release 3.2(1)" section on page 17. Virtual Router Redundancy Protocol (VRRP) Interfaces When a switchover occurs on a switch that is the master for Virtual Router Redundancy Protocol (VRRP) interfaces, the switchover may cause a minor delay. As a result, the VRRP backup (occurring elsewhere) may assume the role of the VRRP master. As a workaround, increase the VRRP advertisement interval for these interfaces. QoS on an MDS 48-port Fibre Channel Module Due to possible differences in parts per million between the MAC ASICs on both sides of an ISL link, there is a potential throughput issue when running QoS over an ISL on an MDS 48-port Fibre Channel module. Specifically, the user may not see traffic throughput that follows the programmed QoS ratios. The throughput ratio on the high and/or medium priority class of service (COS) relative to the low priority COS, may not be as high as the actual programmed ratio. If this situation occurs, you can move the ISL to a port on a different port group on one and/or both sides of the link, or move the ISL to a port on a lower-density card if you require accurate QoS ratios. Maximum Number of Zones Supported in Interop Mode 4 In interop mode 4, the maximum number of zones that is supported in an active zone set is 2047, due to limitations in the connected vendor switch. When IVR is used in interop mode 4, the maximum number of zones supported, including IVR zones, in the active zone set is 2047. The limit for the maximum number of IVR zones per VSAN is 250 zones (two members per zone). Cisco MDS 9000 Family Release Notes for Cisco MDS SAN-OS Release 3.2(1) 32 OL-14116-01