Extreme Networks ExtremeWare XOS Guide Manual page 67

To configure the virtual router from which you receive a Telnet request, use the following command:
configure telnet vr [all | default | <vr_name>]
To change the default TCP port number, use the following command:
configure telnet port [<portno> | default]
The range for the port number is 1 through 65535. The following TCP port numbers are reserved and
cannot be used for Telnet connections: 22, 80, and 1023. If you attempt to configure a reserved port, the
switch displays an error message.
Using ACLs to Control Telnet Access
By default, Telnet services are enabled on the switch. You can restrict Telnet access by using an access
control list (ACL) and implementing an ACL policy. You configure an ACL policy to permit or deny a
specific list of IP addresses and subnet masks for the Telnet port.
There are two methods to load ACL policies to the switch:
Use the
●
edit policy
directly on the switch.
Use the command to transfer a policy that you created using a text editor on another system to
●
tftp
the switch.
For more information about creating and implementing ACLs and policies, see, see
Manager" and Chapter 13,
Sample ACL Policies. The following are sample policies that you can apply to restrict Telnet access.
In the following example named MyAccessProfile.pol, the switch permits connections from the subnet
10.203.133.0/24 and denies connections from all other addresses:
MyAccessProfile.pol
Entry AllowTheseSubnets {
if {
source-address 10.203.133.0 /24;
}
then
{
permit;
}
}
In the following example named MyAccessProfile_2.pol, the switch does not permit connections from
the subnet 10.203.133.0/24 but accepts connections from all other addresses:
MyAccessProfile_2.pol
Entry dontAllowTheseSubnets {
if {
source-address 10.203.133.0 /24;
}
then
{
deny;
ExtremeWare XOS 11.3 Concepts Guide
command to launch a VI-like editor on the switch. You can create the policy
"Access Lists (ACLs)."
Using Telnet
Chapter 12, "Policy
67