Cisco Nexus 1000V Release Notes, Release 4.2(1)SV2(2.1)
Software Compatibility with VMware
Software Compatibility with Cisco Nexus 1000V
Extending VEMs for Centralized Management of Data Centers and Branch Offices
Single VMware Data Center Support
Cisco NX-OS Commands Might Differ from Cisco IOS
Layer 2 Switching: No Spanning Tree Protocol
DHCP Not Supported for the Management IP
Copy Running-Config Startup-Config Command
Dynamic Entries Are Not Deleted for a Linux VM
Source Filter TX VLANs Are Missing After the VSM Restarts
Default SSH Inactive Session Timeout
Queueing Policy Cannot Be Changed in Flexible Upgrade Setup
Clear QoS Statistics Fails on the VSM
Platform, Infrastructure, Ports, Port Channel, and Port Profiles
Obtaining Documentation and Submitting a Service Request
Release: NX-OS Release 4.2(1)SV2(2.1)
This document describes the features, limitations, and bugs for the Cisco Nexus 1000V Release 4.2(1)SV2(2.1) software. The following is the change history for this document.
Added CSCum99528 to Platform, Infrastructure, Ports, Port Channel, and Port Profiles. |
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Added support for vSphere 5.5 in Software Compatibility with VMware and added VXLAN Offload. |
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Updated the value of Active VLANs and VXLANs across all VEMs in Table 1 . |
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Updated the supported limit for vEthernet interfaces per port profile in Table 1 and added CSCug48013 in Resolved Bugs. |
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Added Extending VEMs for Centralized Management of Data Centers and Branch Offices. |
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Updated LACP and added Upstream Switch Ports. |
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Added CSCug23327 in Resolved Bugs. |
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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:
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 5.5, 5.1, and 5.0 release trains. For additional compatibility information, see the Cisco Nexus 1000V Compatibility Information.
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.
This release supports hitless upgrades from Release 4.2(1)SV1(4) and later releases. For additional information, see the Cisco Nexus 1000V Software Upgrade Guide.
The following software features were added in Cisco Nexus 1000V Release 4.2(1)SV2(2.1):
A VXLAN supports two different modes for flood traffic:
– MAC distribution mode (supported only in unicast mode)—In this mode, the unknown unicast flooding in the network is eliminated. Virtual Supervisor Module (VSM) learns all the mac-addresses from VEMs in all VXLANs and distributes those MAC addresses with VTEP IP mappings to other VEMs. Hence, there is no unknown unicast mac-address in the network when VMs on VEMs are communicating and controlled by same VSM.
VXLAN termination (encapsulation and decapsulation) is supported only on virtual switches. As a result, the only endpoints that can connect into VXLANs are VMs that are connected to a virtual switch. Physical servers cannot be in VXLANs and routers or services that have traditional VLAN interfaces cannot be used by VXLAN networks. The only way that VXLANs can currently interconnect with traditional VLANs is through VM-based software routers.
The VXLAN gateways supported are as follows:
The configuration for such VXLAN-VLAN translation/mappings for the VXLAN gateway must be configured through the VSM and must always be a 1:1 mapping for each Layer 2 domain. Each VXLAN gateway can support multiple VXLAN-VLAN mappings.
A VXLAN trunk allows you to trunk multiple VXLANs on a single virtual Ethernet interface. In order to achieve this configuration, you must encapsulate a VXLAN-VLAN mapping on the virtual Ethernet interface.
VXLAN-VLAN mappings are configured through the VSM and must always be a 1:1 mapping for each Layer 2 domain. VXLAN-VLAN mappings are applied on a virtual Ethernet interface using a port-profile. A single port profile can support multiple VLAN-VXLAN mappings.
The Cisco Nexus 1000V supports offloading VXLAN checksum and TSO computations of inner packets for VXLAN encapsulated packets. The VXLAN offload feature is supported only if an adapter supports the offload feature and the VMware supports the offload feature on that adapter. For more information, see the Cisco Nexus 1000V VXLAN Configuration Guide.
You can use multi-MAC addresses to mark a virtual Ethernet interface as capable of sourcing packets from multiple MAC addresses. For example, you can use this feature if you have a virtual Ethernet port and you have enabled VXLAN trunking on it and the VM that is connected to the port bridges packets that are sourced from multiple MAC addresses.
By using this feature, you can easily identify such multi-MAC capable ports and handle live migration scenarios correctly for those ports.
To facilitate a centralized management environment, it is possible to have the VSM at a central location in the main Data Center, while the VEMs are spread across different branch locations. The maximum latency recommended between VSMs and VEMs in such cases should be 100 ms.
This section describes the Cisco Nexus 1000V limitations and restrictions.
Table 1 lists the Cisco Nexus 1000V configuration limits.
The VSMs can be placed in different physical data centers. Note that the previous restrictions requiring the active-standby VSMs in a single physical data center do not apply anymore. |
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2048 VLANs and 2048 VXLANs (with a combined maximum of 4096) |
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Distributed Virtual Switches (DVS) per vCenter with VMware vCloud Director (vCD) |
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Only one connection to vCenter server is permitted at a time. |
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3001 |
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This number can be exceeded if the VEM has available memory. |
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The Cisco Nexus 1000V can be connected to a single VMware vCenter Server data center object. Note that this virtual data center can span multiple physical data centers.
VMotion of the VSM has the following limitations and restrictions:
For more information about VMotion of VSM, see the Cisco Nexus 1000V Software Installation Guide.
The NetFlow configuration has the following support, limitations, and restrictions:
The NetFlow cache table has the following limitation:
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 profiles have the following restrictions or limitations:
Only SSH version 2 (SSHv2) is supported.
For information, see the Cisco Nexus 1000V Security Configuration Guide.
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, see the Cisco Nexus 1000V Command Reference.
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.
For information about Layer 2 switching, see the Cisco Nexus 1000V Layer 2 Switching Configuration Guide.
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:
– 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.
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.
Note This restriction does not apply if LACP offload is enabled. You can check the LACP offload status by using the show lacp offload status command.
All upstream switch ports must be configured in spanning-tree port type edge trunk mode.
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:
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.
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.
When running the copy running-config startup-config command, do not press the PrtScn key. If you do, the command will abort.
On a Linux VM that has multiple adapters, a DHCP release packet is sent from an incorrect interface (because of OS functionality) and the DHCP release packet is dropped. As a result, the binding entry is not deleted. This issue is a Linux issue where the packets from all interfaces go out of one interface (which is the default interface). To avoid this issue, put the interfaces in different subnets and make sure that the default gateways for each interface is set.
When a SPAN (erspan-source) session is created and the source interface is configured as a port channel and PVLAN Promiscuous access is programmed, the filter RX is not configured and the configured programmed filter TX is not persistent on VSM reload.
To work around this issue, configure all the primary and secondary VLANs as filter VLANs while using the port channel with PVLAN Promiscuous access as the source interface.
The default SSH inactive session timeout is 30 minutes, but the timeout setting is disabled by default, so the connection remains active. The exec-timeout command can be used to explicitly configure the inactive session timeout limit.
Queuing is valid starting from Cisco NX-OS Release 4.2(1)SV1(5.1). Any queueing configuration that exists on the VSM in an earlier release will stop working. All port profiles that have a queueing configuration cannot be used. If a port is down, it should be moved to a profile without QoS queueing.
When a policy map of type “queuing” has a class map of type “match-any” without any match criteria, and is applied on an interface, a resource pool is not created for that specific class ID. As a result, the collection of statistics fails and no data is sent back to the VSM. To work around this issue, add a match criteria on the empty class map.
This section includes the following topics:
The following are descriptions of the bugs in Cisco Nexus 1000V Release 4.2(1)SV2(2.1). The IDs are linked to the Cisco Bug Search tool.
The following are descriptions of bugs that are resolved in Cisco Nexus 1000V Release 4.2(1)SV2(2.1). The IDs are linked to the Cisco Bug Search tool.
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:
ftp://ftp.cisco.com/pub/mibs/supportlists/nexus1000v/Nexus1000VMIBSupportList.html
For information on obtaining documentation, submitting a service request, and gathering additional information, see What’s New in Cisco Product Documentation at: http://www.cisco.com/en/US/docs/general/whatsnew/whatsnew.html.
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