Part Number: OL-28542-01
Current Release: NX-OS Release 4.2(1)SV1(5.2b)
This document describes the features, limitations, and caveats for the Cisco Nexus 1000V Release 4.2(1)SV1(5.2b) software. Use this document in combination with documents listed in the “Related Documentation” section. The following is the change history for this document.
December 18, 2012
Created release notes for Release 4.2(1)SV1(5.2b).
February 19, 2013
Added note for VSG solution not supporting VMware vSphere 5.1, and removed a note for Cisco Nexus 1000V software not supporting VMware ESX 5.1.
The Cisco Nexus 1000V provides a distributed, Layer 2 virtual switch that extends across many virtualized hosts. The Cisco Nexus 1000V manages a data center defined by the vCenter Server. Each server in the data center is represented as a line card in the Cisco Nexus 1000V and can be managed as if it were a line card in a physical Cisco switch.
The Cisco Nexus 1000V consists of the following two components:
Virtual Supervisor Module (VSM), which contains the Cisco CLI, configuration, and high-level features.
Virtual Ethernet Module (VEM), which acts as a line card and runs in each virtualized server to handle packet forwarding and other localized functions.
Note The Cisco VSG solution is not supported with VMware vSphere 5.1.
The servers that run the Cisco Nexus 1000V VSM and VEM must be in the VMware Hardware Compatibility list. This release of the Cisco Nexus 1000V supports vSphere 4.1.0, 5.0.0, and 5.1.0 release trains. For additional compatibility information, see the
Cisco Nexus 1000V Compatibility Information, Release 4.2(1)SV1(5.2)
Note All virtual machine network adapter types that VMware vSphere supports are supported with the Cisco Nexus 1000V. Refer to the VMware documentation when choosing a network adapter. For more information, see the VMware Knowledge Base article #1001805.
Software Compatibility with Cisco Nexus 1000V
This release supports hitless upgrades from Release 4.0(4)SV1(3a) and later releases. Upgrades are supported from 4.0(4)SV1(3) and earlier releases. For additional information, see the
Cisco Nexus 1000V Software Upgrade Guide, Release 4.2(1)SV1(5.2)
New and Changed Information
This section provides the following information about Cisco Nexus 1000V Release 4.2(1)SV1(5.2):
1.Only one connection to vCenter server is permitted at a time.
2.This number can be exceeded if VEM has available memory.
Single VMware Data Center Support
The Cisco Nexus 1000V can be connected to a single VMware vCenter Server datacenter object. Note that this virtual datacenter can span across multiple physical data centers.
VMotion of VSM
VMotion of the VSM has the following limitations and restrictions:
VMotion of a VSM is supported for both the active and standby VSM VMs. For high availability, we recommend that the active VSM and standby VSM reside on separate hosts.
If you enable Distributed Resource Scheduler (DRS), you must use the VMware anti-affinity rules to ensure that the two virtual machines are never on the same host, and that a host failure cannot result in the loss of both the active and standby VSM.
VMware VMotion does not complete when using an open virtual appliance (OVA) VSM deployment if the CD image is still mounted. To complete the VMotion, either click
on the VM to disconnect the mounted CD image, or power off the VM. No functional impact results from this limitation.
If you are adding one host in a DRS cluster that is using vSwitch to a VSM, you must move the remaining hosts in the DRS cluster to the VSM. Otherwise, the DRS logic does not work, the VMs that are deployed on the VEM could be moved to a host in the cluster that does not have a VEM, and the VMs lose network connectivity.
For more information about VMotion of VSM, see the
Cisco Nexus 1000V Software Installation Guide, Release 4.2(1)SV1(5.1)
ACLs have the following limitations and restrictions:
IPV6 ACL rules are not supported.
VLAN-based ACLs (VACLs) are not supported.
ACLs are not supported on port channels.
IP ACL rules do not support the following:
– fragments option
– addressgroup option
– portgroup option
– interface ranges
Control VLAN traffic between the VSM and VEM does not go through ACL processing.
The NetFlow configuration has the following support, limitations, and restrictions:
Layer 2 match fields are not supported.
NetFlow Sampler is not supported.
NetFlow Exporter format V9 is supported
NetFlow Exporter format V5 is not supported.
The multicast traffic type is not supported. Cache entries are created for multicast packets, but the packet/byte count does not reflect replicated packets.
NetFlow is not supported on port channels.
The NetFlow cache table has the following limitation:
Immediate and permanent cache types are not supported.
Note The cache size that is configured using the CLI defines the number of entries, not the size in bytes. The configured entries are allocated for each processor in the ESX host and the total memory allocated depends on the number of processors.
Port security has the following support, limitations, and restrictions:
• Port security is enabled globally by default.
feature/no feature port-security
command is not supported.
In response to a security violation, you can shut down the port.
The port security violation actions that are supported on a secure port are
violation action is not supported.
Port security is not supported on the PVLAN promiscuous ports.
Port profiles have the following restrictions or limitations:
There is a limit of 255 characters in a
We recommend that you save the configuration across reboots, which will shorten the VSM bringup time.
We recommend that if you are altering or removing a port channel, you should migrate the interfaces that inherit the port channel port profile to a port profile with the desired configuration, rather than editing the original port channel port profile directly.
If you attempt to remove a port profile that is in use, that is, one that has already been auto-assigned to an interface, the Cisco Nexus 1000V generates an error message and does not allow the removal.
When you remove a port profile that is mapped to a VMware port group, the associated port group and settings within the vCenter Server are also removed.
Policy names are not checked against the policy database when ACL/NetFlow policies are applied through the port profile. It is possible to apply a nonexistent policy.
Telnet Enabled by Default
The Telnet server is enabled by default.
For more information about Telnet, see the
Cisco Nexus 1000V Security Configuration Guide, Release 4.2(1)SV1(5.1)
Only SSH version 2 (SSHv2) is supported.
For more information, see the
Cisco Nexus 1000V Security Configuration Guide, Release 4.2(1)SV1(5.1)
Cisco NX-OS Commands Might Differ from Cisco IOS
Be aware that the Cisco NX-OS CLI commands and modes might differ from those commands and modes used in the Cisco IOS software.
For information about CLI commands, see the
Cisco Nexus 1000V Command Reference, Release 4.2(1)SV1(5.1)
Layer 2 Switching
This section lists the Layer 2 switching limitations and restrictions and includes the following topics:
For more information about Layer 2 switching, see the
Cisco Nexus 1000V Layer 2 Switching Configuration Guide, Release 4.2(1)SV1(5.1)
No Spanning Tree Protocol
The Cisco Nexus 1000V forwarding logic is designed to prevent network loops so it does not need to use the Spanning Tree Protocol. Packets that are received from the network on any link connecting the host to the network are not forwarded back to the network by the Cisco Nexus 1000V.
Cisco Discovery Protocol
The Cisco Discovery Protocol (CDP) is enabled globally by default.
CDP runs on all Cisco-manufactured equipment over the data link layer and does the following:
• Advertises information to all attached Cisco devices.
• Discovers and views information about those Cisco devices.
– CDP can discover up to 256 neighbors per port if the port is connected to a hub with 256 connections.
If you disable CDP globally, CDP is also disabled for all interfaces.
For more information about CDP, see the
Cisco Nexus 1000V System Management Configuration Guide, Release 4.2(1)SV1(5.1)
DHCP Not Supported for the Management IP
DHCP is not supported for the management IP. The management IP must be configured statically.
The Link Aggregation Control Protocol (LACP) is an IEEE standard protocol that aggregates Ethernet links into an EtherChannel.
The Cisco Nexus 1000V has the following restrictions for enabling LACP on ports carrying the control and packet VLANs:
Note These restrictions do not apply to other data ports using LACP.
If LACP offload is disabled, at least two ports must be configured as part of LACP channel.
Note This restriction is not applicable if LACP offload is enabled. You can check the LACP offload status by using the show lacp offload status command.
The upstream switch ports must be configured in
spanning-tree port type edge trunk
mode. For more information about this restriction, see the “Upstream Switch Ports” section.
Upstream Switch Ports
All upstream switch ports must be configured in
spanning-tree port type edge trunk
Without spanning-tree PortFast on upstream switch ports, it takes approximately 30 seconds to recover these ports on the upstream switch. Because these ports are carrying control and packet VLANs, the VSM loses connectivity to the VEM.
The following commands are available to use on Cisco upstream switch ports in interface configuration mode:
spanning-tree portfast trunk
spanning-tree portfast edge trunk
The Cisco Nexus 1010 (1000V) cannot resolve a domain name or hostname to an IP address.
When the maximum transmission unit (MTU) is configured on an operationally up interface, the interface goes down and comes back up.
Layer 3 VSG
When a VEM communicates with Cisco VSG in Layer 3 mode, an additional header with 94 bytes is added to the original packet. You must set the MTU to a minimum of 1594 bytes to accommodate this extra header for any network interface through which the traffic passes between the Cisco Nexus 1000V and the Cisco VSG. These interfaces can include the uplink port profile, the proxy ARP router, or a virtual switch.
VM Name Display Length Limitation
VM names for VMs on ESX 4.1 hosts that exceed 21 characters are not displayed properly on the VSM. When you use a
command that displays the port profile name, for example, the
show vservice port brief port-profile
command, only VMs with names that are 21 characters or less are displayed correctly. Longer VM names may cause the VM name to be truncated, or extra characters to be appended to the VM name. Depending on the network adapter, the name length limitation may vary. For example:
The E1000 or VMXNET 2 network adapters allow 26-character names. At 27 characters, the word ‘.eth’ is appended to the VM name. With each addition to the VM name, a character is truncated from the word ‘.eth’. After 31 characters, the VM name is truncated.
The VMXNET 3 network adapters allow 21-character names. At 22 characters, the word ‘ ethernet’ is appended to the VM name. With each addition to the VM name, a character is truncated from the word ‘ ethernet’. After 30 characters, the VM name is truncated.
Workaround: This is a display issue with ESX Release 4.1 only. Use VM names of 21 characters or less to avoid this issue.
Performing an ISSU from Cisco Nexus 1000V Release 4.2(1)SV1(4) or Release 4.2(1)SV1(4a) to Cisco Nexus 1000V Release 4.2(1)SV1(5.2) using ISO files is not supported. You must use kickstart and system files to perform an ISSU upgrade to Cisco Nexus 1000V Release 4.2(1)SV1(5.2).
Copy Running-Config Startup-Config Command
When running the copy running-config startup-config command, do not press the PrtScn key. If you do, the command will abort.
A Link Aggregation Control Protocol (LACP) port channel member port goes to the suspended state when the port is newly added to the LACP port channel, or the port is removed and re-added to the LACP port channel.
The VSM/VEM licensing for Cisco VSG enters an unlicensed mode after you upgrade from Cisco Nexus 1000V Series switch Release 4.2(1) SV1(5.1) or Release 4.2(1) SV1(5.1a) to Release 4.2(1) SV1(5.2).
The Cisco Management Information Base (MIB) list includes Cisco proprietary MIBs and many other Internet Engineering Task Force (IETF) standard MIBs. These standard MIBs are defined in Requests for Comments (RFCs). To find specific MIB information, you must examine the Cisco proprietary MIB structure and related IETF-standard MIBs supported by the Cisco Nexus 1000V Series switch.
The MIB Support List is available at the following FTP site:
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Internet Protocol (IP) addresses used in this document are for illustration only. Examples, command display output, and figures are for illustration only. If an actual IP address appears in this document, it is coincidental.