Cisco Cisco Evolved Programmable Network Manager 1.2 インストールガイド
18
•
Sub-milliseconds net latency is required across the network links between the primary and secondary servers. Irrespective
of the physical proximity of these two servers, high latency on these links can affect how Cisco EPN Manager maintains
sessions between the primary and secondary servers.
of the physical proximity of these two servers, high latency on these links can affect how Cisco EPN Manager maintains
sessions between the primary and secondary servers.
HA performance is always sensitive to the net throughput that can be delivered by the network that connects the primary and
secondary servers. This restriction applies to at least some degree in every possible deployment model (supported deployment
models are described in
secondary servers. This restriction applies to at least some degree in every possible deployment model (supported deployment
models are described in
). For example, in a geographically dispersed
deployment, the Remote deployment model is more likely to have problems due to low bandwidth and high latency. But if Local
and Campus deployment models are not properly configured, they are also highly susceptible to problems with latency that
result from bandwidth limitations on high-usage networks.
and Campus deployment models are not properly configured, they are also highly susceptible to problems with latency that
result from bandwidth limitations on high-usage networks.
Consider Whether You Can Use Virtual Addresses
Note
To use a virtual address, the addresses for the primary server, secondary server, and virtual IP address must be on the
same subnet.
same subnet.
Virtual IP addresses allow both servers to share the management address. The virtual IP address always points to the primary
server; if failover or failback occurs, the servers will switch IPs.
server; if failover or failback occurs, the servers will switch IPs.
For example: If the primary and secondary servers have the following IP address assignments within the given subnet, the virtual
IP address for both servers can be assigned as follows:
IP address for both servers can be assigned as follows:
•
Subnet mask: 255.255.255.224 (/32)
•
Primary server IP address: 10.10.101.1
•
Secondary server IP address: 10.10.101.2
•
Virtual IP address: 10.10.101.[3-30] e.g., 10.10.101.3. Note that the virtual IP address can be any of a range of addresses
that are valid for the given subnet mask.
that are valid for the given subnet mask.
If you do not use a virtual IP address, configure the devices to forward all syslogs notifications and traps to both servers (for
example, by forwarding them to a given subnet or range of IP addresses that includes both the primary and secondary server).
This configuration must be completed before a failover so that the chance of losing data is reduced or completely eliminated.
You do not need to make any changes to the secondary server during installation; simply provision the primary and secondary
servers with their individual IP addresses, as normal.
example, by forwarding them to a given subnet or range of IP addresses that includes both the primary and secondary server).
This configuration must be completed before a failover so that the chance of losing data is reduced or completely eliminated.
You do not need to make any changes to the secondary server during installation; simply provision the primary and secondary
servers with their individual IP addresses, as normal.
Choose a High Availability Deployment Model
Cisco EPN Manager’s HA feature supports the following three deployment models. The main restriction is on the HA
performance and reliability, which depends on the bandwidth and latency criteria discussed in
performance and reliability, which depends on the bandwidth and latency criteria discussed in
.
Deployment Model
Both servers are located:
Example
Local
On same subnet (Layer 2 proximity)
Servers located in same Data Center
Campus
Different subnets connected via LAN
Servers located in same campus, city, state, or province
Remote
Different subnets connected via WAN
Servers are geographically dispersed