This command adds an IPv4 or IPv6 summary address for the specified level on the specified router process.
| area_name | Specifies the router process to which the summary address is to be added. |
| ipv4_address_mask | Specifies an IPv4 summary address. |
| ipv6_address_mask | Specifies an IPv6 summary address. |
| level | Specifies the IS-IS level for the summary address. The level 1 option summarizes level 2 routes leaked to level 1. The level 2 option summarizes level 1 routes that are advertised into level 2. |
No summarization.
Route summaries are useful for minimizing the number of LSPs required to describe reachability for an area. The summary address is advertised instead of the actual reachable addresses. This is particularly useful for L1/L2 routers in which the summary address is used in a single LSP instead of including a part or all of the addresses reachable in its level 1 area.
Note that a summary address is only advertised if at least one route matches the summary address. If there is no route present that matches the summary address exactly, a blackhole route is installed for the summary address. If an interlevel filter permits any route matched by the summary address, and that route is present, the summary address is advertised.
If multiple summary addresses are installed in which one or more supersede each other (10.0.0.0/8 and 10.0.0.0/16, for example), only the more specific summary addresses are advertised.
The following command adds an IPv4 summary address to areax:
configure isis area areax add summary-address 10.0.0.0/8
This command was first available in ExtremeXOS 12.1.
This command is available on platforms with a Core license.
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