Arista vEOS, Руководство по настройке

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Chapter
3
Cloud High Availability
In the cloud, resources can be deployed across different regions or multiple locations within a region for fault tolerance
reasons. AWS Availability Zones and Azure Availability Sets (or Fault Domains; Azure currently supports different
resource groupings within a physical datacenter) are examples of cloud high availability offerings. When deploying
vEOS Routers to enhance your cloud's network capability, deploy the vEOS Routers as a high availability pair using
the vEOS Cloud High Availability feature that fits your cloud's high availability design.
The Cloud High Availability (Cloud HA) feature adds support to make the vEOS Router deployment more resilient
to various failure scenarios in the cloud, such as:
• vEOS Router instance goes down due to underlying cloud infrastructure issues.
• vEOS Router instance is unable to forward traffic due to connectivity issues in the cloud infrastructure.
• vEOS Router experiences an internal issue leading to unavailability.
vEOS Router HA pair with Cloud HA is an active-active deployment model for different cloud high availability design
in a region. Each vEOS Router in an HA pair provides enhanced routing capabilities as the gateway (or next-hop router
for certain destinations) for the subnets to which the vEOS routers connect. The two vEOS Router peers monitor the
liveliness of each other by using Bidirectional Forwarding Detection (BFD) between the router interfaces. In case of
the cloud infrastructure issues or vEOS router failure, the active vEOS router takes over as the gateway or next-hop
for the subnets that were connected to the peer router through cloud-specific API calls that modify the corresponding
cloud route table(s) according to pre-configured information.
Cloud HA Topology
This diagram shows an example of a vEOS Router Cloud HA implementation.
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