Archives for the month of: February, 2013

When the Nexus 1000V was first released, the only available control mode between VSM (Virtual Supervisor Module) and VEM (Virtual Ethernet Module) was layer 2 mode. This meant that the VSM and VEM had to be layer 2 adjacent (i.e. on the same VLAN). Layer 3 control mode was released a while ago however, which meant that the VSM and VEM could be on different VLANs / subnets. L3 control also makes things slightly simpler to set up as you don’t need to worry about trunking control / packet VLANs everywhere and setting up port groups for these.

Assuming you want to use L3 control mode, there are a couple of decisions to make: Read the rest of this entry »

In a FabricPath deployment, it is important to have all FabricPath VLANs configured on every switch participating in the FP domain. Why is this? The answer lies in the way multi-destination trees are built.

A multi-destination tree is used to forward broadcast, unknown unicast and multicast traffic through the FabricPath network:


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It’s often a good recommendation to use multiple linecard modules in a switch chassis – this makes it possible to spread port-channels across linecards so if one fails, convergence times are kept to a minimum. If you are using vPC on the Nexus 7000, this recommendation becomes even more important. Why? Let’s imagine we have a vPC setup with two Nexus 7000s and a downstream switch, connected via vPC. Each Nexus 7000 has a single M1 10GE linecard (used for both the peer-link and the upstream connections to the core), plus a single M1 1GE linecard (used to connect to the downstream switch, plus the Peer-Keepalive link):


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What is the ASA 1000V? It is a virtualised edge firewall that runs in conjunction with the Nexus 1000V switch. The ASA 1000V runs as a virtual machine, and provides a secure default gateway for other VMs in the environment. Many of the features from the physical ASAs are supported, such as NAT, failover and site-to-site IPSec VPNs, however there are a few features which are not supported in the current release such as IPv6, multiple contexts, dynamic routing and transparent mode firewalling.

An ASA 1000V has four “physical” interfaces – ‘Inside’, ‘Outside’, ‘Management’ and ‘Failover’:


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