
Configuring VINES Services
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If the broadcast packet is a StreetTalk broadcast packet, which propagates
StreetTalk information, or a Time Sync Service broadcast packet, which
propagates time information, the router ignores the hop count. First, the router
checks to see if the interface that provides the best path back to the originating
node received the packet. If it did, the router retransmits the packet on all
other interfaces (without modifying the hop-count field). Otherwise, the
router determines that the packet has looped back, and discards it.
The router recognizes a StreetTalk broadcast packet or a Time Sync Service
broadcast packet by examining the destination port field of the packet’s ICP
header. The router sets the destination port field to 0x0000f for all StreetTalk
packets and 0x0007 for all Time Sync Service packets.
• Nonbroadcast packets
When the router receives a nonbroadcast packet with a different destination
address, the router must forward the packet. First, it reassembles the packet, if
necessary. Then, it refers to its next hop routing table to determine the next
hop. Finally, it forwards the packet to this hop.
VINES Nonsequenced Routing Update Protocol
The VINES Nonsequenced Routing Update Protocol (Nonsequenced RTP)
maintains a local routing table that VINES IP can refer to when it selects paths.
Nonsequenced RTP also distributes this information about the network topology
among the servers and clients in the network. Nonsequenced RTP packets have a
4-byte header that immediately follows the VINES IP header (F
igure 1-6).
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