Exceptional Scenarios

This section explains instances of exceptional route compression behavior.

  • When a node does not have any best route.

    Consider the routing table shown in Route Manager‘s Table When There is No Best Route for a Node. When a node does not have any best route, children are uncompressed, if they were already compressed. Also this node is uncompressed, if it had previously been compressed.

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Route Manager‘s Table When There is No Best Route for a Node

Prefix Gateway Number of best paths Compressed?
192.0.0.0/8 10.203.174.68 1 No
192.168.0.0/16 10.203.174.68 0 No
192.168.224.0/24 10.203.174.68 1 No
192.168.225.0/24 10.203.174.68 1 No
  • When a node contains only a multicast route.

    Route compression is applied to unicast routes only. If a node contains only a multicast route, the compression algorithm is not applied to the node. Therefore multicast nodes are considered as nodes with no best unicast routes as shown in Route Manager‘s Table When a Node Contains Only a Multicast Route.

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Route Manager‘s Table When a Node Contains Only a Multicast Route

Prefix Gateway Unicast/Multicast Compressed?
192.0.0.0/8 10.203.174.68 Unicast Route No
192.168.0.0/16 10.203.174.68 Multicast Route No
192.168.224.0/24 10.203.174.68 Unicast Route No
192.168.225.0/24 10.203.174.68 Unicast Route No