When A Router Forwards An Ipx Packet - Novell NETWARE 6-DOCUMENTATION Manual

When a Router Forwards an IPX Packet

If the packet is addressed to the router, the appropriate socket process
handles it internally; otherwise, the router forwards the packet.
NOTE:
Packets that must be handled internally are those addressed directly to the
router and those broadcast (destination node = 0xFFFFFFFFFFFF) to any network
segment to which the router is directly connected. Usually, only RIP, SAP, and
diagnostic packets fall into this category.
When forwarding packets, the router can take one of two possible actions. If
the packet is destined for a network number to which the router is directly
connected, the router performs the following tasks:
1. The router places the destination node address from the IPX header in the
Destination Address field of the MAC header.
2. The router places its own node address in the Source Address field of the
MAC header.
3. The router increments the Transport Control field of the IPX header and
forwards the packet to the destination node segment.
IMPORTANT:
If the Transport Control field equals the maximum allowed hop
count before the field is incremented, the router discards the packet. For RIP
routers, the hop count limit is 16; for NLSP routers, this limit can be set to any
number between 8 and 127.
Note also that broadcast packets are never rebroadcast onto the network
segment from which they are received.
If the router is not directly connected to the segment on which the final
destination node resides, it sends the packet to the next router in the path to the
destination node, as follows:
1. The router places the node address of the next router in the Destination
Address field of the MAC header.
The router gets this information from its Routing Information Table.
2. The router places its own node address in the Source Address field of the
MAC header.
3. The router increments the Transport Control field in the IPX header and
forwards the packet to the next router.
23
Understanding