Enabling Soft Reconfiguration; Prohibiting The Advertisement Of Default Routes; Disabling Igp Synchronization - HP 7102dl - ProCurve Secure Router Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP

Enabling Soft Reconfiguration

Soft reconfiguration allows a network administrator to reconfigure BGP
policies without clearing active BGP sessions. Administrators can then insti-
tute new policies at any time without forcing the neighbors to reestablish their
connection and without disrupting traffic. The ProCurve Secure Router sup-
ports soft reconfiguration for inbound updates. You enable soft reconfigura-
tion on a per-neighbor basis. Enter:
ProCurve(config-bgp-neighbor)# soft-reconfiguration inbound
Soft reconfiguration is enabled by default.

Prohibiting the Advertisement of Default Routes

A router that runs BGP may have a default route in its routing table. Often a
BGP router is also part of an IGP network (for example, it is an OSPF ASBR),
and it is responsible for distributing a default route for all external traffic to
other routers in the AS. By default, the router is prohibited from transmitting
this route with this command:
Syntax: no default-originate
Currently, the no option is the only option available.

Disabling IGP Synchronization

If a BGP router advertises a route to external neighbors that routers within
the AS have not yet learned, the internal routers may receive, and be forced
to drop, traffic they cannot handle. IGP synchronization was used by earlier
applications of BGP to solve this problem. It forces the BGP router to wait
until an IGP has distributed a route throughout the AS before it sends the route
out of the AS.
However, many autonomous systems now use iBGP to propagate BGP routes
throughout an AS. For such networks, IGP synchronization only slows up the
BGP process. A private AS does not need to use IGP synchronization to ensure
that external traffic is properly routed because it does not transit external
traffic at all.
Currently, the no option for IGP synchronization is the only option available
on the ProCurve Secure Router:
ProCurve(config-bgp)# no synchronization
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