Lantronix MPS100 EPS Reference Manual - Page 48

Using the Security Table

Page 48 highlights

Security Server Configuration The IP address must be four segments of 0-255 each. A 255 in any segment applies to all numbers in that range such that 192.0.1.255 includes all addresses of 192.0.1.n. A trailing zero in any address is shorthand for "all addresses in this range are disabled, for both directions and for all ports." The following two commands are equal. Figure 4-22: Set IPsecurity Command Local> SET IPSECURITY 192.0.1.0 Local> SET IPSECURITY 192.0.1.255 OUT DISABLED IN DISABLED Parameters can be added after the address term to change the defaults. Incoming and Outgoing Disabled are the default settings for any Set/Define IPsecurity command. Incoming refers to users on other hosts attempting to log into the Server. Outgoing refers to local users connecting to other TCP/IP hosts. Port number 0 corresponds to the virtual ports (that is, users who log into the Server from the network). If no ports are specified on the command line, all ports, both physical and virtual, are included by default. Individual entries can be removed by entering Clear/Purge IPsecurity with no parameters other than the address. This command form is not valid for any addresses with zeros in any segment. Figure 4-23: Clear IPsecurity Command Local> CLEAR IPSECURITY 192.1.1.102 The entire security table can be cleared with one command: Figure 4-24: Clearing Security Table Local> CLEAR IPSECURITY ALL 4.7.2.1 Using the Security Table There are two basic rules for checking a TCP/IP connection for legality. First, a more specific rule takes precedence over a less specific one. For example, if connections to 192.0.1.255. are disabled but connections to 192.0.1.78 are enabled, a connection to 192.0.1.78 will succeed. Second, in the absence of any rule that restricts a connection, access is allowed. If this behavior is not desired, include an entry of the following form: Figure 4-25: Setting IPsecurity Local> SET IPSECURITY 255.255.255.255 IN DISABLED OUT DISABLED This is the least specific rule in the table, and will ensure that connections fail unless otherwise allowed by another entry (recall that all ports are included in the rule by default). If no entries are defined in the table, all connection attempts will succeed. Also, if the connecting user has privileged status, the connection will be allowed regardless of the entries in the table. Note: Managers should try enabling and disabling certain addresses on their local network to see what they can and cannot do if they are unclear as to the rules on the use of the security table. 4-12

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Security
Server Configuration
4-
12
The IP address must be four segments of 0-255 each. A 255 in any segment applies to all numbers in that
range such that 192.0.1.255 includes all addresses of 192.0.1.
n
. A trailing zero in any address is shorthand
for “all addresses in this range are disabled, for both directions and for all ports.” The following two
commands are equal.
Figure 4-22:
Set IPsecurity Command
Parameters can be added after the address term to change the defaults. Incoming and Outgoing Disabled are
the default settings for any
Set/Define IPsecurity
command. Incoming refers to users on other hosts
attempting to log into the Server. Outgoing refers to local users connecting to other TCP/IP hosts.
Port number 0 corresponds to the virtual ports (that is, users who log into the Server from the network). If
no ports are specified on the command line, all ports, both physical and virtual, are included by default.
Individual entries can be removed by entering
Clear/Purge IPsecurity
with no parameters other than the
address. This command form is not valid for any addresses with zeros in any segment.
Figure 4-23:
Clear IPsecurity Command
The entire security table can be cleared with one command:
Figure 4-24:
Clearing Security Table
4.7.2.1
Using the Security Table
There are two basic rules for checking a TCP/IP connection for legality. First, a more specific rule takes
precedence over a less specific one. For example, if connections to 192.0.1.255. are disabled but
connections to 192.0.1.78 are enabled, a connection to 192.0.1.78 will succeed. Second, in the absence of
any rule that restricts a connection, access is allowed. If this behavior is not desired, include an entry of the
following form:
Figure 4-25:
Setting IPsecurity
This is the least specific rule in the table, and will ensure that connections fail unless otherwise allowed by
another entry (recall that all ports are included in the rule by default).
If no entries are defined in the table, all connection attempts will succeed. Also, if the connecting user has
privileged status, the connection will be allowed regardless of the entries in the table.
Note:
Managers should try enabling and disabling certain addresses on their local
network to see what they can and cannot do if they are unclear as to the rules on
the use of the security table.
Local> SET IPSECURITY 192.0.1.0
Local> SET IPSECURITY 192.0.1.255 OUT DISABLED IN DISABLED
Local> CLEAR IPSECURITY 192.1.1.102
Local> CLEAR IPSECURITY ALL
Local> SET IPSECURITY 255.255.255.255 IN DISABLED OUT DISABLED