Enterasys X-Pedition XSR, Cli Reference Manual

Page: 178 / 684

OSPF Commands
5-102 Configuring the Internet Protocol
Next Mode
Router configuration: XSR(config-router)#
Default
OSPF disabled
Example
The following example enables OSPF routing:
XSR(config)#router ospf 2
XSR(config-router)#
summary address
This command summarizes locally ‐ sourced (Type ‐ 5) routes on the XSR which are redistributed
from other protocols into OSPF. Type ‐ 7 translations are not summarized. Other actions
implemented include:
• A summary range becomes active if it includes at least one locally sourced route being
redistributed into OSPF. If an active summary range is advertised, then a discard route will be
installed for the summary range. Conversely, when it becomes inactive, the discard route is
removed.
• Activated summary ranges to be advertised will result in a Type ‐ 5 Linke ‐ State Announcement
(LSA). If they include a NSSA area, then they will also produce a Type ‐ 7 LSA for each NSSA
area.
• The type/cost of the summary range is the highest type/cost among all included locally ‐
sourced routes. The forwarding address is 0.
• Summary ranges may overlap. So, for a locally ‐ sourced route, the most specific range becomes
active.
• Appendix E processing provides a unique link ‐ state ID for all Type ‐ 5 LSAs advertised, be they
the result of Type ‐ 7 to Type ‐ 5 translations, summarization or locally ‐ sourced routes which are
not summarized.
• A Type ‐ 5 LSA generated by translation may supplant a Type ‐ 5 LSA originating from a local
source. This will not affect what is being generated into a NSSA because translations are not
advertised into NSSA areas.
• If for a given prefix, both a summary and a locally ‐ sourced route exist, the summary will be
considered superior even if the summary includes only this locally ‐ sourced route.
• Needless reorigination of Type ‐ 5 LSAs will be avoided. For example. importing locally ‐
sourced routes which do not change the type/cost of a summary will not result in
reorigination of the summary LSA.
• Type ‐ 7 translations are not affected by this command. If an overflow condition occurs then
both summary ranges and non ‐ summarized routes will be flushed from the AS.
Syntax
summary-address < ip-address >< ip-mask >[ not-advertise ][ tag < tag >]