Nokia Network Voyager for IPSO 4.0 Reference Guide 403To configure the routing preferences1. Click Routing Options under Configuration > Routing Configuration in the tree view.2. Enter 10 in the OSPF edit box.3. Enter 40 in the RIP edit box; then click Apply.This configuration makes the OSPF route the preferred route. To make the RIP route be thepreferred route, enter 40 for OSPF and 10 for RIP.BGPBorder Gateway Protocol (BGP) is an inter-AS protocol, meaning that it can be deployed withinand between autonomous systems (AS). An autonomous system is a set of routers under a singletechnical administration. An AS uses an interior gateway protocol and common metrics to routepackets within an AS; it uses an exterior routing protocol to route packets to other ASes.NoteThis implementation supports BGP version 4 and 4++.BGP sends update messages that consist of network number-AS path pairs. The AS pathcontains the string of ASes through which the specified network can be reached. An AS path hassome structure in order to represent the results of aggregating dissimilar routes. These updatemessages are sent over TCP transport mechanism to ensure reliable delivery. BGP contrasts withIGPs, which build their own reliability on top of a datagram service.As a path-vector routing protocol, BGP limits the distribution of router reachability informationto its peer or neighbor routers.Support for BGP-4++IPSO implements BGP-4++ to support multiprotocol extensions and exchange IPv6 prefixes asdescribed in RFCs 2545, 2858, and 3392.You must use an IPv4 address for the router ID (BGP identifier). After the BGP session is up,prefixes can be advertised and withdrawn by sending normal UPDATE messages that includeeither or both of the new multiprotocol attributes MP_REACH_NLRI (used to advertisereachability of routes) and MP_UNREACH_NLRI (used to withdraw routes).The new attributes are backward compatible. If two routers have a BGP session and only onesupports the multiprotocol attributes, they can still exchange unicast IPv4 routes even thoughthey cannot exchange IPv6 routes.On each peer you configure the type of routes (capability) that should be exchanged betweenpeers. Choose from the following selections: IPv4 unicast (the default) IPv6 unicast
