Configuring System Administrator Settings : Configuring SNMP settings : SNMP authentication and access control
  
SNMP authentication and access control
The features in this page apply to SNMPv1, v2c, and v3 unless noted otherwise:
• Security Names—Identify an individual user (v1 or v2c only).
• Secure Groups—Identify a security-name, security model by a group, and referred to by a group-name.
• Secure Views—Create a custom view using the VACM that controls who can access which MIB objects under agent management by including or excluding specific OIDs. For example, some users have access to critical read-write control data, while some users have access only to read-only data.
• Security Models—A security model identifies the SNMP version associated with a user for the group in which the user resides.
• Secure Access Policies—Defines who gets access to which type of information. An access policy is composed of <group-name, security-model, security-level, read-view-name>.
An access policy is the configurable set of rules, based on which the entity decides how to process a given request.
To set secure usernames
1. Choose Administration > System Settings: SNMP ACLs to display the SNMP ACLs page.
SNMP ACLs page - security names
2. Under Security Names, complete the configuration as described in this table.
Control
Description
Add a New Security Name
Displays the controls to add a security name.
Security Name
Specify a name to identify a requestor allowed to issue gets and sets (v1 and v2c only). The specified requestor can make changes to the view-based access-control model (VACM) security name configuration.
This control doesn’t apply to SNMPv3 queries. To restrict v3 USM users from polling a particular subnet, use the RiOS Management ACL feature, located in the Administration > Security: Management ACL page.
Traps for v1 and v2c are independent of the security name.
Community String
Specify the password-like community string to control access. Use a combination of uppercase, lowercase, and numerical characters to reduce the chance of unauthorized access to the SteelHead.
Community strings don’t allow printable 7-bit ASCII characters, except for white spaces. Also, the community strings can’t begin with a pound sign (#) or a hyphen (-).
If you specify a read-only community string (located in the SNMP Basic page under SNMP Server Settings), it takes precedence over this community name and allows users to access the entire MIB tree from any source host. If this is not desired, delete the read-only community string.
To create multiple SNMP community strings on a SteelHead, leave the default public community string and then create a second read-only community string with a different security name. You can also delete the default public string and create two new SNMP ACLs with unique names.
Source IP Address and Mask Bits
Specify the host IPv4 or IPv6 address and mask bits to which you permit access using the security name and community string.
Add
Adds the security name.
Remove Selected
Select the check box next to the name and click Remove Selected.
3. Click Apply to apply your changes to the running configuration.
4. Click Save to Disk to save your settings permanently.
To set secure groups
1. Choose Administration > System Settings: SNMP ACLs to display the SNMP ACLs page.
2. Under Groups, complete the configuration as described in this table.
Control
Description
Add a New Group
Displays the controls to add a new group.
Group Name
Specify a group name.
Security Models and Name Pairs
Click the + button and select a security model from the drop-down list:
• v1 or v2c—Displays another drop-down menu. Select a security name.
• v3 (usm)—Displays another drop-down menu. Select a user.
To add another Security Model and Name pair, click the plus sign (+).
Add
Adds the group name and security model and name pairs.
Remove Selected
Select the check box next to the name and click Remove Selected.
3. Click Apply to apply your changes to the running configuration.
4. Click Save to Disk to save your settings permanently.
To set secure views
1. Choose Administration > System Settings: SNMP ACLs to display the SNMP ACLs page.
2. Under Views, complete the configuration as described in this table.
Control
Description
Add a New View
Displays the controls to add a new view.
View Name
Specify a descriptive view name to facilitate administration.
Includes
Specify the Object Identifiers (OIDs) to include in the view, separated by commas. For example, .1.3.6.1.4.1. By default, the view excludes all OIDs.
You can specify .iso or any subtree or subtree branch.
You can specify an OID number or use its string form. For example, .iso.org.dod.internet.private.enterprises.rbt.products.steelhead.system.model
Excludes
Specify the OIDs to exclude in the view, separated by commas. By default, the view excludes all OIDs.
Add
Adds the view.
Remove Selected
Select the check box next to the name and click Remove Selected.
3. Click Apply to apply your changes to the running configuration.
4. Click Save to Disk to save your settings permanently.
To add an access policy
1. Administration > System Settings: SNMP ACLs to display the SNMP ACLs page.
2. Under Access Policies, complete the configuration as described in this table.
Control
Description
Add a New Access Policy
Displays the controls to add a new access policy.
Group Name
Select a group name from the drop-down list.
Security Level
Determines whether a single atomic message exchange is authenticated. Select one of these from the drop-down list:
• No Auth—Doesn’t authenticate packets and doesn’t use privacy. This is the default setting.
• Auth—Authenticates packets but doesn’t use privacy.
• AuthPriv—Authenticates packets using AES or DES to encrypt messages for privacy.
A security level applies to a group, not to an individual user.
Read View
Select a view from the drop-down list.
Add
Adds the policy to the policy list.
Remove Selected
Select the check box next to the name and click Remove Selected.
3. Click Apply to apply your changes to the running configuration.
4. Click Save to Disk to save your settings permanently.