Dell PowerSwitch S4128F-ON EMC SmartFabric OS10 User Guide Release 10.5.1 - Page 1150

● Password-less login is disabled by default. To enable, use the username sshkey or username sshkey filename commands. ● Configure the list of cipher algorithms using the ip ssh server cipher cipher-list command. ● Configure key exchange algorithms using the ip ssh server kex key-exchange-algorithm command. ● Configure hash message authentication code (HMAC) algorithms using the ip ssh server mac hmac-algorithm command. ● Configure the SSH server listening port using the ip ssh server port port-number command. ● Configure the SSH server to be reachable on the management VRF using the ip ssh server vrf command. ● Configure the SSH login timeout using the ip ssh server login-grace-time seconds command, from 0 to 300; default 60. To reset the default SSH prompt timer, use the no ip ssh server login-grace-time command. ● Configure the maximum number of authentication attempts using the ip ssh server max-auth-tries number command, from 0 to 10; default 6. To reset the default, use the no ip ssh server max-auth-tries command. The max-auth-tries value includes all authentication attempts, including public-key and password. If you enable both, public-key based authentication and password authentication, the public-key authentication is the default and is tried first. If it fails, the number of max-auth-tries is reduced by one. In this case, if you configured ip ssh server max-authtries 1, the password prompt does not display. Regenerate public keys When enabled, the SSH server generates public keys by default and uses them for client authentication: ● A Rivest, Shamir, and Adelman (RSA) key using 2048 bits. ● An Elliptic Curve Digital Signature Algorithm (ECDSA) key using 256 bits ● An Ed25519 key using 256 bits NOTE: RSA1 and DSA keys are not supported on the OS10 SSH server. An SSH client must exchange the same public key to establish a secure SSH connection to the OS10 switch. If necessary, you can regenerate the keys used by the SSH server with a customized bit size. You cannot change the default size of the Ed25519 key. The crypto key generate command is available only to the sysadmin and secadmin roles. 1. Regenerate keys for the SSH server in EXEC mode. crypto ssh-key generate {rsa {2048|3072|4096} | ecdsa {256|384|521} | ed25519} 2. Enter yes at the prompt to overwrite an existing key. Host key already exists. Overwrite [confirm yes/no]:yes Generated 2048-bit RSA key 3. Display the SSH public keys in EXEC mode. show crypto ssh-key After you regenerate SSH public keys, disable and re-enable the SSH server to use the new public keys. Restarting the SSH server does not impact current OS10 sessions. RESTCONF API RESTCONF API allows to configure and monitor an OS10 switch using HTTP with the Transport Layer Security (TLS) protocol. For more information about RESTCONF API, see RESTCONF API. Restrict SNMP access To filter SNMP requests on the switch, assign access lists to an SNMP community. Both IPv4 and IPv6 access lists are supported. These points are applicable when you assign an ACL to an SNMP community: ● By default, SNMP requests from all hosts are allowed. ● You can only apply permit ACL rues to an SNMP community. deny ACL rules do not take effect if you apply them. ● To permit SNMP requests for multiple hosts, apply individual permit ACL rules for hosts or prefixes. 1150 Security