NMIS supports using SNMPv3 for securing the collection of sensitive network information. This is especially important from core switches and routers which if compromised could have a considerable business impact. This configuration note does not include details about the SNMPv3 protocol, and assumes that people are wanting to use the authPriv (Authentication and Privilege) mode which is the most secure.
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The first step is to enable SNMPv3 on in the /etc/snmp/snmpd.conf file, then restart the daemon.
Required Linux SNMPD Configuration for SNMPv3 communication to
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NMIS9
Add the following configuration to the top, edit the /etc/snmp/snmpd.conf file as the root user, e.g.
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| NMIS9 name | Name | OID | Notes |
|---|---|---|---|
| des | usmDESPrivProtocol | 1.3.6.1.6.3.10.1.2.1 | RFC3411 |
| 3des | usm3DESPrivProtocol | 1.3.6.1.4.1.14832.1 | RFC3411 |
| aes (or aes128) | usmAESCfb128PrivProtocol | 1.3.6.1.4.1.14832.2 | Blumenthal implementation of SNMPv3 |
| aes192 | usmAESCfb192PrivProtocol | 1.3.6.1.4.1.14832.3 | Blumenthal implementation of SNMPv3 |
| aes256 | usmAESCfb256PrivProtocol | 1.3.6.1.4.1.14832.4 | Blumenthal implementation of SNMPv3 |
| aes192c | cusmAESCfb192PrivProtocol | 1.3.6.1.4.1.9.12.6.1.1 | Cisco implementation of SNMPv3 AES192 |
| aes256c | cusmAESCfb256PrivProtocol | 1.3.6.1.4.1.9.12.6.1.2 | Cisco implementation of SNMPv3 AES256 |
| aes192c2 | usmAES192Cisco2PrivProtocol | 1.3.6.1.4.1.9.12.6.1.101 | A mysterious version 2 of the Cisco implementation, possibly related to pysnmp |
| aes256c2 | usmAES256Cisco2PrivProtocol | 1.3.6.1.4.1.9.12.6.1.102 | A mysterious version 2 of the Cisco implementation, possibly related to pysnmp |
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Many Cisco devices will support SHA256 but only AES128 (which given the entropy is reasonable "AES-128 would take about 2.61*10^12 years to crack" https://www.ubiqsecurity.com/128bit-or-256bit-encryption-which-to-use/).
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