Summary

More information

Networking Configuration

Networking requirements are contingent upon how Neverfail Engine is to be deployed. To deploy as a High Availability (HA) solution, a LAN configuration is required. To deploy Neverfail Engine for Disaster Recovery (DR), a WAN configuration is required. To deploy in a Trio, both a LAN and a WAN configuration are used. Each network configuration has specific configuration requirements to ensure proper operation.

 

Note: Neverfail recommends that the Neverfail Channel be configured on the same network as the Public network. If required to isolate for replication, the Neverfail Channel can be configured on a different subnet than the Public network.

 

When Neverfail Engine is installed using a single NIC configuration, upon completion of installation, Neverfail recommends that you add an additional NIC to each server (Primary/Secondary/Tertiary) in order to provide network redundancy and then move the Neverfail Channel configuration to the newly added NICs. For more information about adding additional NICs to Neverfail Engine, see Adding an Additional Network Interface Card in this guide.

Local area Network (LAN)

When deployed in a LAN environment, Neverfail Engine requires that both servers use the same Public IP address. Each server also requires a Neverfail Channel IP address.

Wide Area Network (WAN)

Neverfail Engine supports sites with different subnets. In this scenario, the Primary and Secondary servers in the Neverfail Engine Pair or Secondary and Tertiary in a Trio will require unique Public IP addresses in each subnet and a unique Neverfail Channel IP address in each subnet for each server.

WAN Requirements

WAN deployments require the following:

• Persistent static routing configured for the channel connection(s) where routing is required
  

Note: This requirement can be avoided if the channel IP addresses are in the same subnet as the Public IP address in which case the default gateway can be used for routing.

• One NIC (minimum)
  
• At least one Domain Controller at the Disaster Recovery (DR) site
  
• If the Primary and DR site uses the same subnet:
  • During install, follow the steps for a LAN or VLAN on the same subnet
    
  • Both the Primary and Secondary servers in the pair use the same Public IP address
    
• If the Primary and DR site use different subnets:
  • During install, follow the steps for a WAN
    
  • The Primary and Secondary servers in the Neverfail Engine pair require a separate Public IP address and a Neverfail Channel IP address
    
  • Provide a user account with rights to update DNS using the DNSUpdate.exe utility provided as a component of Neverfail Engine through the Engine Management Service User Interface tasks or Neverfail Advanced Management Client Applications > Tasks > User Accounts
    
  • Neverfail recommends integrating Microsoft DNS into AD so that DNSUpdate.exe can identifyall DNS Servers that require updating
    
  • At least one Domain Controller at the DR site
    
  • Refer to the following articles in the Neverfail Knowledge Base:
    

Knowledge base article KB-1425 – Configuring DNS with Neverfail IT Continuity Engine in a WAN Environment

Knowledge base article KB-1599 – Configuring Neverfail IT Continuity Engine to Update BIND9 DNS Servers Deployed in a WAN  

Bandwidth

Neverfail Engine includes automatic bandwidth optimization in WAN environments. This feature compresses data transferred over the Neverfail Channel, optimizing the traffic for low bandwidth

connections causing some additional CPU load on the active server.

 

Determine the available bandwidth and estimate the required volume of data throughput to determine acceptable latency for the throughput. Additionally, the bandwidth can affect the required queue size to accommodate the estimated volume of data. Neverfail recommends making a minimum of 1Mbit of spare bandwidth available to Neverfail Continuity Engine.

Latency

Latency has a direct effect on data throughput. Latency on the link should not fall below the standard defined for a T1 connection (2-5ms for the first hop).

Neverfail SCOPE Data Collector Service can assist in determining the available bandwidth, required bandwidth, and server workload. For more information about Neverfail SCOPE Data Collector Service, contact Neverfail Professional Services.

Network Interface Card (NIC) Configuration

Neverfail Engine supports use of either multiple NICs or a single NIC.

 

This release of Neverfail Engine adds very flexible support for configuring NICs with Public and Channel connections.

 

The following scenarios are some supported:

• Single NIC Installation : Neverfail Engine is installed on a server having a single NIC, which is shared by both the Public Network and the Neverfail Channel. This can simplify the install process by avoiding down-time when adding a NIC.
  
• Adding a NIC post-installation . Using a single NIC results in a potential single point of failure. To prevent a single point of failure, additional NICs can be added post-installation, and the Public and Neverfail Channel IP addresses distributed across these. See Adding a Network Card.
  
• Multiple NIC Installation. Neverfail Engine can be installed on a server with multiple NICs. You can choose which NIC will be used for the Neverfail Channel connection.
  

Primary Server

The Primary server is configured with the following connections:

• A Public network connection configured with a static Public IP address, network mask, gatewayaddress, preferred DNS server address, and secondary (if applicable) DNS server address.
  
• Neverfail Channel connection(s) configured with a static IP address in the same or a different subnet than the Public IP address, and with a different IP address than the Secondary server channel, and network mask. No gateway or DNS server address is configured where a dedicated NIC is used. NetBIOS will be filtered on the passive server to prevent server name conflicts.
  
• The Register this connection's addresses in DNS check box must be cleared on the Neverfail Channel connection(s) prior to installing Neverfail Engine.
  

Secondary/Tertiary Server

The Secondary/Tertiary server will have the same number of NICs as the Primary server, with the same names and will be configured as follows:

• A Public connection configured with a static IP address, network mask, gateway address, preferred DNS server address, and secondary (if applicable) DNS server address.
  

Note: If deploying as a pair in a WAN, the Public IP address of the Secondary server may be in a different subnet than the Primary server.

 

Note: If configured in a trio, the Primary and Secondary servers are configured for LAN deployment and the Tertiary server is configured for a WAN deployment. 

• Neverfail Channel network connection(s) configured on the same or a separate dedicated NIC with a static IP address in the same or a different subnet than the Secondary/Tertiary Public IP address, and with a different IP address than the Primary or Secondary (for Tertiary) server's Neverfail Channel NIC, and a network mask. A gateway address and DNS address are not configured by the user. NetBIOS will be filtered to prevent server name conflicts.
  
• The Register this connection's addresses in DNS check box must be cleared on the Neverfail Channel connection(s) prior to installing Neverfail Engine. 
  

Note: Neverfail recommends that this network change be made during a scheduled downtime to minimize risk of a system outage. Once this is done, you should immediately replace the dynamic "A" record for the Neverfail Engine protected server with a static entry with a TTL of 45 seconds.

Applies To

Neverfail Continuity Engine v8.0 and Later

KBID-2978