Information About IVR Without NAT or Autotopology
Before configuring an IVR SAN fabric without IVR in NAT mode or IVR auto topology mode, consider the following general guidelines:
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If you change an FSPF link cost, ensure that the FSPF path distance (the sum of the link costs on the path) of any IVR path is less than 30,000.
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IVR-enabled VSANs can be configured when an interop mode is enabled or disabled.
Domain ID Guidelines
Before configuring domain IDs, consider the following guidelines:
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Configure unique domain IDs across all VSANs and switches participating in IVR operations if you are not using IVR NAT. The following switches participate in IVR operations:
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All edge switches in the edge VSANs (source and destination)
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All switches in transit VSANs
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Minimize the number of switches that require a domain ID assignment. This ensures minimum traffic disruption.
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Minimize the coordination between interconnected VSANs when configuring the SAN for the first time as well as when you add each new switch.
You can configure domain IDs using one of two options:
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Configure the allowed-domains list so that the domains in different VSANs are non-overlapping on all participating switches and VSANs.
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Configure static, non-overlapping domains for each participating switch and VSAN.
Note |
In a configuration involving IVR without NAT, if one VSAN in the IVR topology is configured with static domain IDs, then the other VSANs (edge or transit) in the topology must be configured with static domain IDs. |
Transit VSAN Guidelines
Before configuring transit VSANS, consider the following guidelines:
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Traffic between the edge VSANs only traverses through the shortest IVR path.
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Transit VSAN information is common to all IVR zone sets. Sometimes, a transit VSAN can also act as an edge VSAN in another IVR zone.
Besides defining the IVR zone membership, you can choose to specify a set of transit VSANs to provide connectivity between two edge VSANs:
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If two edge VSANs in an IVR zone overlap, then a transit VSAN is not required (though, not prohibited) to provide connectivity.
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If two edge VSANs in an IVR zone do not overlap, you may need one or more transit VSANs to provide connectivity. Two edge VSANs in an IVR zone will not overlap if IVR is not enabled on a switch that is a member of both the source and destination edge VSANs.
Border Switch Guidelines
Before configuring border switches, consider the following guidelines:
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Configure IVR only in the relevant border switches.
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Border switches require Cisco MDS SAN-OS Release 1.3(1) or later.
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A border switch must be a member of two or more VSANs.
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A border switch that facilitates IVR communications must be IVR enabled.
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IVR can also be enabled on additional border switches to provide redundant paths between active IVR zone members.
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The VSAN topology configuration must be updated before a border switch is added or removed.