CCIE Practical Studies: Security (CCIE Self-Study)

Limiting LSP Flooding

As with any routing protocol, IS-IS can consume a large amount of your bandwidth under certain conditions. If you plan on implementing a network with a large amount of redundant links, flooding of LSPs can limit network scalability. You have the option of reducing LSP flooding in the following ways:

• Blocking flooding on specific interfaces— This method offers an advantage over using mesh groups because it is easier to configure and understand, and fewer LSPs are flooded. Blocking flooding on all links can give you the best scaling performance but often results in a less robust network structure.

• Configuring mesh groups— This method offers an advantage over full blocking in that mesh groups allow LSPs to be flooded over ...