Building a whitelist through QoS

Managing the device securely

On AT-8948, AT-9900, AT-9900s, and x900 Series switches, use classifiers to build a whitelist and QoS to apply it.

Configuration 1. Create classifiers to match telnet traffic from permitted IP addresses to the switch’s IP address.

2.Create a classifier to match all telnet traffic to the switch’s IP address.

3.Create a flow group and add the classifiers for permitted traffic to it.

4.Create a second flow group with a higher ID number and add the classifier that matches all telnet traffic to it.

Products

AT-8948

x900-48 Series

AT-9900 Series

AT-9924Ts x900-24 Series

Software Versions

2.7.3 and later

5.Create the rest of the QoS framework—traffic class and policy.

6.Apply the policy to all ports to stop telnet from all directions.

QoS is an incredibly versatile hardware-level packet filtering mechanism. For more information about setting up QoS on these switches, see How To Configure QoS On AT-8948,AT-9900,AT-9900s And x900 Series Switches. This How To Note is available from www.alliedtelesis.com/resources/literature/howto.aspx.

Example To permit only the host with IP address 172.30.1.144 to telnet to the switch 172.28.40.70:

create classifier=1 ipsa=172.30.1.144/32 ipda=172.28.40.70/32 tcpd=23

create classifier=2 ipda=172.28.40.70/32 tcpd=23 create qos flowgroup=1 action=forward

create qos flowgroup=2 action=discard create qos trafficclass=1

create qos policy=1

add qos flowgroup=1 classifier=1 add qos flowgroup=2 classifier=2 add qos trafficclass=1 flowgroup=1 add qos trafficclass=1 flowgroup=2 add qos policy=1 trafficclass=1 set qos port=all policy=1

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