Nokia Network Voyager for IPSO 4.0 Reference Guide 473NoteOnly the server portion of the Router Discovery Protocol is supported.IPSO implements only the ICMP router discovery server portion, which means that a Nokiarouter can advertise itself as a candidate default router, but it will not adopt a default router usingthe router discovery protocol.The ICMP Router Discovery Service provides a mechanism for hosts attached to a multicast orbroadcast network to discover the IP addresses of their neighboring routers. This sectiondescribes how you can configure a router to advertise its addresses by using ICMP RouterDiscovery.Router Discovery OverviewThe router discovery server runs on routers and announces their existence to hosts. It does thisby periodically multicasting or broadcasting a router advertisement to each interface on which itis enabled. These advertisements contain a list of all the router addresses on a given interfaceand their preference for use as a default router.Initially, these router advertisements occur every few seconds, then fall back to every fewminutes. In addition, a host can send a router solicitation, to which the router responds with aunicast router advertisement, unless a multicast or broadcast advertisement is due in a moment.Each router advertisement contains an advertisement lifetime field indicating for how long theadvertised addresses are valid. This lifetime is configured such that another router advertisementis sent before the lifetime expires. A lifetime of zero (0) indicates that one or more addresses areno longer valid.On systems that support IP multicasting, the router advertisements are sent by default to the all-hosts multicast address 224.0.0.1. However, you can specify the use of broadcast. When routeradvertisements are being sent to the all-hosts multicast address, or an interface is configured forthe limited-broadcast address 255.255.255.255, all IP addresses configured on the physicalinterface are included in the router advertisement. When the router advertisements are being sentto a net or subnet broadcast, only the address associated with that net or subnet is included.NoteRouter discovery is not supported when clustering is enabled.Configuring Router DiscoveryTable 29 describes the parameters that you can configure for router discovery.
