IBM Bridge/ Heritage, User Manual

Page: 75 / 167

7-10
Command Sets for Command Line Interface
7. portfilter
Syntax:
portfilter [<source port> all|<destination ports>]
Description:
The
portfilter
command allows control over the bridge’s
forwarding and broadcasting behavior. By default, when a multicast
or an unknown packet is received on a port (referred to above as the
source port), it will be forwarded to all other bridge ports (referred to
above as the destination ports). Each bridge port may have its
behavior modified separately. The first example below configures the
bridge so that packets arriving on port 2 will only be forwarded to
ports 3, 4 and 5, and packets arriving on port 3 will only be forwarded
to port 1. All other ports retain their default behavior. Note that this
command does not force packets arriving on the source port to be
sent to all specified destination ports. The bridge retains its learning
behavior, so unicast packets, once their destination is known to the
bridge, will still only be sent to one port. Note also that the bridge
itself (for example when attached to the IP router) will always
forward to all ports, and will always be forwarded to by all ports. The
default behavior can be restored by calling this command with the
argument “
all
”, as shown in the second example. The ports are
specified as integers, as displayed by the
device list
command.
When using this command in the
initbridge
configuration file, ports
are numbered in the order in which the
device add
commands are
given, starting from 1. If no arguments are given, the current settings
for each port are displayed.
Example 1:
DSL bridge> portfilter 2 3 4 5
DSL bridge> portfilter 3 1
Example 2:
DSL bridge> portfilter 2 all
DSL bridge> portfilter 3 all