Redundant Connections

Contents
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If a modeled device is configured with a pool of IP addresses available to it for use in communicating on the network, 
DX NetOps Spectrum
 can use these IP addresses to create redundant connectivity with that device. If the redundancy feature is enabled on a device and 
DX NetOps Spectrum
 cannot reach the device using the designated primary address, 
DX NetOps Spectrum
 attempts to re-establish contact using the list of available IP addresses.
Redundancy Preferred Addresses List
A device that supports the 
DX NetOps Spectrum
 redundancy feature has a Redundancy Preferred Addresses list containing the device’s interface IP addresses that is created when the router is originally modeled. 
DX NetOps Spectrum
 uses this list in determining redundant connectivity to the device. Devices have a primary address that is determined when the device is modeled. The 
DX NetOps Spectrum
 modeling process includes loopback functionality. If the VNM is configured to use the loopback feature, the first valid loopback address detected for the device is used as device model’s primary address.
Removal of Shared IP Addresses from Preferred List
 
DX NetOps Spectrum
 automatically removes the IP addresses that it detects as “shared” from a Redundancy Preferred Addresses list for a device model. 
DX NetOps Spectrum
 places these shared addresses in the Redundancy Excluded Addresses list. Such shared IP addresses are not used when 
DX NetOps Spectrum
 attempts to restore communication with a lost device that was using redundant IP addresses.
If you manually add a shared IP address to the Redundancy Preferred Addresses list, 
DX NetOps Spectrum
 automatically moves it back to the Redundancy Excluded Addresses list. You cannot see this list until you close and reopen the current view.
Device Primary Address
By default, the primary address for a device is the IP address assigned to the device for network communications. You can change the primary address in OneClick if the network address for the device changes. If 
DX NetOps Spectrum
 cannot contact the device using its primary address, it attempts to contact the device using the first IP address in the Redundancy Preferred Addresses List.
You can change a device’s primary address and the IP addresses listed in the Redundancy Preferred Addresses list using the IP Redundancy subview.
IP Redundancy Subview
The IP Redundancy subview displays the attributes and settings 
DX NetOps Spectrum
 uses to create and monitor redundant communication paths to the device. Access the IP Redundancy subview by selecting a device in either the Navigation panel, the List tab, or the Topology tab, and then selecting the Information tab in the Component Detail panel. The IP Redundancy subview appears in the Information tab.
Enable Redundancy
When this attribute is set to Yes, 
DX NetOps Spectrum
 uses the addresses in a modeled device’s Redundancy Preferred Addresses list, if it exists, to contact a device when the primary address is not available.
Generate Redundancy Alarms
When this attribute is set to Yes, 
DX NetOps Spectrum
 generates an alarm when a device cannot be contacted using its primary address.
Select Preferred Redundant Addresses
The Redundancy Preferred Addresses list displays IP addresses that a device can use for communicating on the network. You can manually add or remove IP addresses to or from the Redundancy Preferred Addresses list for a device.
 
Follow these steps:
 
  1. Select the device with a redundant IP address.
  2. Click the Information tab and expand the IP Redundancy subview.
  3. Click Configure next to Primary Address.
    The Preferred Addresses dialog opens.
  4. Click Add below the Redundancy Preferred Addresses list.
  5. Enter the IP address that you want to add to the list in the Add IP Address dialog, and click OK.
    The IP address now appears in the Redundancy Preferred Addresses list.
  6. Click OK.
    The changes to the device’s Redundancy Preferred Addresses list are applied.
Exclude Redundant Addresses
The Redundancy Excluded Addresses list displays IP addresses that a device cannot use for communicating on the network. You can manually add or remove IP addresses to or from a device’s Redundancy Excluded Addresses list.
 
Follow these steps:
 
  1. Select the device for which you want to add an excluded IP address.
  2. Click the Information tab and expand the IP Redundancy subview.
  3. Click Configure next to Primary Address.
    The Preferred Addresses dialog opens.
  4. Click Add below the Redundancy Excluded Addresses list.
  5. Enter the IP address that you want to add to the excluded list Add dialog and click OK.
    The IP address now appears in the Redundancy Excluded Addresses list.
    You can also select an address in the Preferred list and move it to the Excluded list by clicking the single right arrow located between the two lists. Similarly, you can move an address from the Excluded list to the Preferred list by selecting the address in the Excluded list and clicking the single left arrow located between the two lists.
About Shared IPs in Device Communication
Since any of your shared IP addresses will already have been added to the Redundancy Excluded Addresses list, the 
DX NetOps Spectrum
 redundancy intelligence will never attempt to communicate with a device using a shared IP. 
DX NetOps Spectrum
 will also never assign a shared IP address to the PrimaryAddress attribute.
Also, if you try to write a new value to a device model’s NetworkAddress or PrimaryAddress attribute, if it is a shared IP address, the new value is not written and a warning dialog opens.