Setting Up
89
Internetwork Packet Exchange
103-000176-001
August 29, 2001
Novell Confidential
Manual
99a
38
July 17, 2001
3
Press Esc and save your changes.
4
Press Esc to return to the Internetworking Configuration menu.
Controlling the Propagation of Type 20 Packets
Novell Internet Access Server 4.1 enables you to control the propagation of
type 20 packets with the Advanced Packet Type 20 Flooding parameter. Type
20 is an IPX packet type that refers to any propagated packet. NetBIOS
packets, for example, are type 20 packets.
The Advanced Packet Type 20 Flooding parameter can be set to one of the
following options:
0
—Router discards, rather than propagates, any type 20 packet it
receives. This option completely disables type 20 packet propagation.
1
—Router receives and propagates type 20 packets through
all
its
interfaces, regardless of whether some of the interfaces are
equal-cost
routes
to the same source.
2
—Router propagates type 20 packets only through interfaces that do not
lead back to the source of the packets. For example, if Router A receives
a type 20 packet from Router B, Router A forwards the packet only
through interfaces that do not lead back to Router B. This is a packet
forwarding mechanism known as
reverse path forwarding
.
The router does not propagate type 20 packets through the same interface
from which it receives them. This is known as
split horizon
, a technique
used with RIP and other distance vector routing protocols.
3
—Router propagates type 20 packets the same way as option 2, but
does
not
forward them across WAN connections.
If you use FILTCFG to configure NetBIOS packet filters, be aware of the
following interactions between these filters and the Advanced Packet Type 20
Flooding parameter:
Setting Advanced Packet Type 20 Flooding to 1 (disabled) overrides the
effect of NetBIOS packet filters operating on any network interface.
Conversely, the action of NetBIOS packet filters on any network interface
overrides the effect of setting the Advanced Packet Type 20 Flooding
parameter to 2 (enabled).