user manual

Configuring Data-Link Switching Plus
DLSw+ Configuration Task List
BC-300
Cisco IOS Bridging and IBM Networking Configuration Guide
78-11737-02
To display the contents of the reachability caches, use the following command in privileged EXEC
command mode:
Use the group keyword to display the reachability information for the border peer.
Explorer Firewalls
An explorer firewall permits only a single explorer for a particular destination MAC address or NetBIOS
name to be sent across the WAN. While an explorer is outstanding and awaiting a response from the
destination, subsequent explorers for that MAC address or NetBIOS name are merely stored. When the
explorer response is received at the originating DLSw+, all explorers receive an immediate local
response. This eliminates the start-of-day explorer storm that many networks experience. Configure the
dlsw timer command to enable explorer firewalls. See the “Configuring DLSw+ Timers” section on
page 310 for details of the command.
To enable explorer firewalls, use the following command in global configuration mode:
NetBIOS Dial-on-Demand Routing
This feature allows you to transport NetBIOS in a dial-on-demand routing (DDR) environment by
filtering NetBIOS Session Alive packets from the WAN. NetBIOS periodically sends Session Alive
packets as LLC2 I-frames. These packets do not require a response and are superfluous to the function
of proper data flow. Furthermore, these packets keep dial-on-demand interfaces up and this up time
causes unwanted per-packet charges in DDR networks. By filtering these NetBIOS Session Alive
packets, you reduce traffic on the WAN and you reduce some costs that are associated with
dial-on-demand routing.
To enable NetBIOS DDR, use the following command in global configuration mode:
The following command enables NetBIOS DDR:
dlsw netbios keepalive-filter
Command Purpose
Router# show dlsw reachability [[group [value] |
local | remote] | [mac-address [address]
[netbios-names [name]
Displays content of group, local and remote caches.
Command Purpose
Router(config)# dlsw timer
{icannotreach-block-time | netbios-cache-timeout
| netbios-explorer-timeout | netbios-group-cache
| netbios-retry-interval |
netbios-verify-interval | sna-cache-timeout |
explorer-delay-time | sna-explorer-timeout |
explorer-wait-time | sna-group-cache |
sna-retry-interval | sna-verify-interval} time
Tunes an existing configuration parameter.
Command Purpose
Router(config)# dlsw netbios keepalive-filter
Enables NetBIOS DDR.