3120 has high CPU with FFE enabled and IP firewall disabled

[redbarron]

ADTRAN, Inc. OS version R12.2.0.SA

  Mainline Version: ENM.16.93

  P4 Changelist: 268653

  Checksum: 9C1988B5

  Built on: Wed Nov 16 11:29:53 2016

Boot ROM version 17.02.01.00

  Checksum: D2C8

  Built on: Fri Apr 04 07:22:20 2008

  Compatibility Version: 0

Copyright (c) 1999-2016, ADTRAN, Inc.

Platform: NetVanta 3200, part number 1203860G1

Task Id    Task Name        PRI STA   (count)     (usec)     (usec)     (1sec)

1          Idle               0 W   138862470        993          0       0.00

3          PC Config          7 S   209541485        936     951405      95.14

4          PacketRouting     44 W    38371951         34       4171       0.42

The config is a PPP 1 interface cross connected to a single T1 and Eth0/1 connected to a firewall.  Added the FFE  to eth0/1 and disabled the Firewall and no change.  Any help would be greatly appreciated.

[redbarron]

I have 11 devices that are doing the exact same thing.  Any assistance would be greatly appreciated. 

[jayh · Accepted solution]

Is the device connected to the Internet? If so, have you locked down administrative access to trusted networks? It could very well be brute-force attacks against telnet, ssh, http, https.

ip access-list standard management-list

permit [list of trusted networks and wildcard mask]

line telnet 0 4

access-class management-list in

line ssh 0 4

access-class management-list in

http ip access-class management-list in

http ip secure-access-class management-list in

[redbarron]

The above with also limiting SNMP access has gotten the CPU utilization down to an acceptable performance.  TY.