Watchdog Packet Spoofing - Novell NETWARE 6-DOCUMENTATION Manual

Watchdog Packet Spoofing

30
Internetwork Packet Exchange
To configure static routes and services for permanent and on-demand calls,
you can use either of the following utilities:
NIASCFG, which you also use for configuring boards and network
interfaces, and for enabling protocols and bindings on the router. If you
use NIASCFG, you must configure all routes and services manually.
STATICON, the static routes and services configuration utility for IPX.
STATICON discovers which routes and services are available through a
remote router and then adds them automatically to the static routing table
on a local router. Because STATICON gathers and exchanges the
information automatically, it is essential for configuring large numbers of
static routes and services.
NetWare servers use the Watchdog protocol to validate workstation
connections periodically. When a workstation is logged in to a server but has
not transmitted a packet for some period of time (the default is 5 minutes), the
server sends a watchdog query packet to the workstation. If the workstation
does not reply with a watchdog response packet after 5 minutes, the server
sends additional queries at specified intervals until 15 minutes have elapsed.
If the workstation still has not replied, the server terminates the connection.
With several workstations operating over an on-demand call, the exchange of
watchdog packets can keep the connection active most of the time. Depending
on the telecommunications carrier you use for the connection, this can become
expensive.
You can avoid this problem by configuring your router to perform watchdog
spoofing . This means that the router captures watchdog query packets on their
way to a workstation and responds on behalf of the workstation without
activating the on-demand call. Because of the spoofing, however, the
workstation's server connection remains occupied unless it logs out. A way to
avoid this is for the remote server to execute a forced logout of all
workstations at a predetermined time (midnight, for example), so that all
server connections are freed for the next day.
Figure 4 on page 31
call.
shows how watchdog spoofing works over an on-demand