Administrator Guide

● SNMP traps for the spanning tree protocol (STP) and multiple spanning tree protocol (MSTP) state changes are based on
BRIDGE MIB (RFC 1483) for STP and IEEE 802.1 draft ruzin-mstp-mib-02 for MSTP.
SNMPv3 Compliance With FIPS
This functionality is supported on the Z9000 platform.
SNMPv3 is compliant with the Federal information processing standard (FIPS) cryptography standard. The Advanced
Encryption Standard (AES) Cipher Feedback (CFB) 128-bit encryption algorithm is in compliance with RFC 3826. SNMPv3
provides multiple authentication and privacy options for user configuration. A subset of these options are the FIPS-approved
algorithms: HMAC-SHA1-96 for authentication and AES128-CFB for privacy. The other options are not FIPS-approved
algorithms because of known security weaknesses. The AES128-CFB privacy option is supported and is compliant with RFC
3826.
The SNMPv3 feature also uses a FIPS-validated cryptographic module for all of its cryptographic operations when the system
is configured with the fips mode enable command in Global Configuration mode. When the FIPS mode is enabled on the
system, SNMPv3 operates in a FIPS-compliant manner, and only the FIPS-approved algorithm options are available for SNMPv3
user configuration. When the FIPS mode is disabled on the system, all options are available for SNMPv3 user configuration.
The following table describes the authentication and privacy options that can be configured when the FIPS mode is enabled or
disabled:
FIPS Mode Privacy Options Authentication Options
Disabled des56 (DES56-CBC)
aes128 (AES128-CFB)
md5 (HMAC-MD5-96)
sha (HMAC-SHA1-96)
Enabled aes128 (AES128-CFB) sha (HMAC-SHA1-96)
To enable security for SNMP packets transferred between the server and the client, you can use the snmp-server user
username group groupname 3 auth authentication-type auth-password priv aes128 priv-password
command to specify that AES-CFB 128 encryption algorithm needs to be used.
Dell(conf)#snmp-server user snmpguy snmpmon 3 auth sha AArt61wq priv aes128 jntRR59a
In this example, for a specified user and a group, the AES128-CFB algorithm, the authentication password to enable the server
to receive packets from the host, and the privacy password to encode the message contents are configured.
SHA authentication needs to be used with the AES-CFB128 privacy algorithm only when FIPS is enabled because SHA is then
the only available authentication level. If FIPS is disabled, you can use MD5 authentication in addition to SHA authentication with
the AES-CFB128 privacy algorithm
You cannot modify the FIPS mode if SNMPv3 users are already configured and present in the system. An error message is
displayed if you attempt to change the FIPS mode by using the fips mode enable command in Global Configuration mode.
You can enable or disable FIPS mode only if SNMPv3 users are not previously set up. If previously configured users exist on the
system, you must delete the existing users before you change the FIPS mode.
Keep the following points in mind when you configure the AES128-CFB algorithm for SNMPv3:
1. SNMPv3 authentication provides only the sha option when the FIPS mode is enabled.
2. SNMPv3 privacy provides only the aes128 privacy option when the FIPS mode is enabled.
3. If you attempt to enable or disable FIPS mode and if any SNMPv3 users are previously configured, an error message is
displayed stating you must delete all of the SNMP users before changing the FIPS mode.
4. A message is logged indicating whether FIPS mode is enabled for SNMPv3. This message is generated only when the first
SNMPv3 user is configured because you can modify the FIPS mode only when users are not previously configured. This log
message is provided to assist your system security auditing procedures.
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Simple Network Management Protocol (SNMP)