User`s guide

Setting Up Pipeline Security
Using filters to secure the network
7-16 Preliminary January 30, 1998 Pipeline User’s Guide
6
Close and save the profile.
Expect callback support
If Ping or Telnet attempt to reach a far end that is using callback security, it
causes a problem. Ping and telnet try continuously to open a connection and
reject the return callback because the process is already trying to establish a
connection.
To remedy the situation, set Expect Callback to Yes. This puts the number of any
far end that does not connect (for any reason) on a list that disallows calls to that
destination for 90 seconds. This gives the far end an opportunity to complete the
callback.
Note:
Expect Callback should only be set to Yes in dialout profiles.
Set Expect Callback to Yes by doing the following:
1
Open Ethernet
>
Connections
>
any profile
>
Telco Options.
2
Set Exp Callback to Yes.
Now if an outgoing connect from that profile fails (for any reason), you will be
forced to wait 90 seconds before attempting to connect again.
Using filters to secure the network
Network security is related to packets coming in from any wide-area network
(WAN) connection. The most direct method of securing the network is with
filters.
Note:
For recommendations about ICMP Redirect packets, see “Recommended
security measures” on page 7-1.
Network security filters are data filters, which may be applied to incoming or
outgoing data streams, or both. Data filters can prevent certain packets from
reaching the local network or going out from the local network to the WAN. For
example, you can use data filters to drop packets addressed to particular hosts, or
prevent certain types of packets from reaching the local network.