Disabling Igp Synchronization; Configuring Route Summarizations; Setting Administrative Distance For Bgp Routes - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

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

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

Configuring Route Summarizations

By default, BGP interfaces on the ProCurve Secure Router do not summarize
routes. Currently, this is the only available option.

Setting Administrative Distance for BGP Routes

Your private network should be running an IGP such as RIP or OSPF. The
routes BGP discovers for external sites may be redistributed into this protocol,
or they may be used in conjunction with the IGP routes.
If the router must choose between a BGP route and an identical route
discovered using a different method, it compares the routes' administrative
distances. A route's administrative distance indicates how trusted the source
of a route is. BGP defines different administrative distances for external
routes, routes internal to the AS and local routes.
To set the administrative distance for routes discovered by BGP, enter:
Syntax: distance bgp <administrative distance for external routes> <administrative
distance for routes internal to the AS> <administrative distance for local routes>
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