Cisco Nexus 5000 Series Release Notes for Release 5.0(3)N2(2) (June 2011)

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Cisco Nexus 5000 Series and Cisco Nexus 2000 Series Release Notes, for Cisco NX-OS Release 5.0(3)N2(2) and Release 5.0(3)N2(1)
Limitations
2008 May 14 15:55:43 switch %KERN-3-SYSTEM_MSG: FCP_ERRFCP_PORT:
gat_fcp_isr_ip_fcmac_sync_intr@424, jiffies = 0x7add9a:Unknown intr src_id 41 - kernel
These messages are informational only, and result in no loss of functionality.
Configuration Synchronization Limitation
When you remove a switch profile using the no switch-profile name [all-config | local-config]
command, the configuration in the switch profile is immediately removed from the running
configuration. This disrupts the configurations that were present in the switch profile. For example, port
channel and vPC configurations are disrupted. For current information about this issue, refer to
CSCtl87240 and CSCtl87260.
Limitations on the Cisco Nexus 5010 and Cisco Nexus 5020
The limitations on the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch are as follows:
• Traffic going out the Ethernet SPAN destination is always tagged. The SPAN destination can be in
the access or trunk mode and frames on the SPAN source port can be tagged or untagged. Frames
are always tagged internally as they travel through the system. Information about whether the frame
was originally tagged or untagged, as it appeared in the SPAN source, is not preserved in the SPAN
destination. The spanned traffic exiting the SPAN destination port always has the VLAN tag on it.
The correct VLAN tag is applied on the frame as it goes out the SPAN destination. The only
exception is if frames ingress on a SPAN source port on an invalid VLAN. In this case, vlan 0 is
applied on a spanned frame.
• Spanned FCoE frames do not preserve original SMAC and DMAC fields. The Ethernet header gets
modified as the frame is spanned to the destination. The modified header fields are displayed when
monitored on the SPAN destination.
• The CoS value in spanned FCoE frames on the Ethernet SPAN destination port does not match with
the CoS value in the SPAN FCoE source frame. The CoS value on the captured SPAN FCoE frame
should be ignored.
• The class-fcoe cannot be removed even if Fibre Channel is not enabled on a switch.
• If a port drains traffic at a rate less than 100 Kbps, it is errdisabled in 10 seconds to avoid buffer
exhaustion. However, if the drain rate is larger than 100 Kbps, the port may not be consistently
errdisabled within 10 seconds which exhaust ingress buffers and discard frames. Use the shut
command to disable the slow-draining port.
• The multicast storm control functionality in the Cisco Nexus 5000 Series does not distinguish
between IP, non-IP, registered, or unregistered multicast traffic. All multicast traffic is subject to a
single-multicast storm control policer when configured.
IGMP Snooping Limitation
On the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch with a Cisco Nexus 2000 Series
Fabric Extender (FEX) installed, unregistered IP multicast packets on one VLAN are forwarded to other
VLANs where IGMP snooping is disabled. We recommend that you do not disable IGMP snooping on
the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch. A static IGMP join can be configured
for devices intended to receive IP multicast traffic but not to send IGMP join requests. This limitation
applies to the Cisco Nexus 5010 switch and the Cisco Nexus 5020 switch only.