Is vPC layer 2 or layer 3?
vPC & L3 connectivity Designs Use separate Layer 3 links to connect L3 device (like router or firewall in routed mode for instance) to a vPC domain (Figure 50). Do not use a Layer 2 vPC to attach L3 device to a vPC domain unless L3 device can statically route to the HSRP address configured on vPC peer devices.
What traffic goes over vPC peer link?
L2 traffic
It is a special link for carrying L2 traffic between the VPC peer switches when there is a link failure. Normally it should get little use. Before the peer link will come up, you also have to set up VPC keepalives to detect dual active peers when the VPC peer link is down.
What does layer3 peer router do?
This enable either switch to accept packets on behalf of it’s peer. The second command is layer3 peer-router. This is the command that tells the Nexus to not decrement the TTL.
What is the purpose of vPC peer link?
vPC Peer-link This link is used to synchronize the state between vPC peer devices via vPC control packets which creates the illusion of a single control plane. In addition the vPC peer-link provides the necessary transport for multicast, broadcast, unknown unicast traffic and for the traffic of orphaned ports.
What is difference between vPC and VSS?
2) In VSS there will be single control plane for both the switches, where as in vPC there will be separate control plane for every switch. 3) VSS can support L3 port-channels across multiple chassis,however, vpc is used for L2 port-channels only.
What is vPC protocol?
vPC (Virtual Port Channel) is the Cisco Proprietary feature that is only working on Cisco Nexus Components. vPC use to make Nexus devices logically single devices for the end host or devices. vPC is also known as Multi-chassis EtherChannel (MEC).
Does vPC peer link carry traffic?
The vPC peer link carries control traffic between two vPC switches and also multicast, broadcast data traffic.
What happens if vPC peer link goes down?
If peer-link fails, then all the member ports from vPC secondary node will be suspended. Here important to note, keep-alive is active in this scenario, which allowing nodes to exchange heartbeat.
What is vPC peer switch?
The vPC peer switch is introduced to address performance concerns around these STP convergence events. This feature allows a pair of Cisco Nexus 7000 Series devices to appear as a single STP root in the Layer 2 topology. In the vPC peer switch mode, STP BPDUs are sent from both vPC peer devices.
What is vPC peer gateway?
The vPC peer-gateway functionality allows a vPC switch to act as the active gateway for packets that are addressed to the router MAC address of the vPC peer. This feature enables local forwarding of such packets without the need to cross the vPC peer-link.
What happens if vPC peer-link goes down?
Can vPC peering across regions?
Amazon EC2 now allows peering relationships to be established between Virtual Private Clouds (VPCs) across different AWS regions.
What is split brain in vPC?
Basically, in the vPC world, all links are set to forward, and nothing blocks at layer-2 because Spanning Tree is not really in place here. Cisco calls it a “split-brain” scenario. If that vPC peer-link fails for any reason, both switches assume the role of primary. This then creates the forwarding-loop-from-hell.
What is difference between EtherChannel and vPC?
vPC (Virtual Port-Channel), also known as multichassis EtherChannel (MEC) is a feature on the Cisco Nexus switches that provides the ability to configure a Port-Channel across multiple switches (i.e. vPC peers). vPC is similar to Virtual Switch System (VSS) on the Catalyst 6500s.
What is keep alive link in vPC?
vPC Peer-Keepalive- vPC Peer-keepalive is a routed (Layer-3) link between both peer switches (Nexus-1 & Nexus-2). The purpose of this link is to check the liveness of peer switch. This link will be a segregated link from the others or subnet, it can be in different vrf.
What is the difference between vPC and VSS?
Is vPC peering two way?
A VPC peering connection is a networking connection between two VPCs that enables you to route traffic between them using private IPv4 addresses or IPv6 addresses. Instances in either VPC can communicate with each other as if they are within the same network.
Is VPC peering bidirectional?
The simplest way to connect two VPCs is to use VPC Peering. In this setup, a connection enables full bidirectional connectivity between the VPCs. This peering connection is used to route traffic between the VPCs.
Can a VPC switch run a dynamic routing protocol?
The vPC switches can even run HSRP or VRRP, and be the default gateway. In this particular example, traffic may follow either vPC uplink. Incidentally, the duplicate frame prevention rule does not apply in this case, one of the hosts uses an orphan port. So, with that cleared up, what about running a dynamic routing protocol such as OSFP?
How does a VPC uplink work?
One host is connected with vPC. The other host is connected to only one of the switches (an orphan port). These hosts still send packets to each other, just like they would over any normal switch. The vPC switches can even run HSRP or VRRP, and be the default gateway. In this particular example, traffic may follow either vPC uplink.
How do I configure the nexus for dynamic routing and VPC?
There is a small amount of configuration on the Nexus. First, use peer-gateway . This enable either switch to accept packets on behalf of it’s peer. The second command is layer3 peer-router. This is the command that tells the Nexus to not decrement the TTL. If you’re mixing dynamic routing and vPC, work out your topology during the design phase.
What is the best topology for a VPC switch?
If the vPC switches are Nexus 3500’s, 5000’s, or 6000’s, the topology above is fine. Peering traffic will traverse the vPC peer-link.