SolarWinds Platform SSH communication uses algorithms and ciphers for device security. These are the list of supported algorithms and ciphers for NPM, NCM, and SolarWinds Platform.

Example errors from Session Traces showing algorithm negotiation or authentication issues between NCM (client) and device (server):

Connection Error : System.Exception: Could not negotiate key exchange algorithm

Connection Error : WeOnlyDo.Exceptions.SSH.AuthorizationException: Authentication with the server failed.

The Session Traces will show what algorithms are supported by NCM (client), as in the example below:

EncryptionList: aes128-ctr,aes128-cbc,3des-cbc,blowfish-cbc,aes192-ctr,aes192-cbc,aes256-ctr,aes256-cbc,chacha20-poly1305@openssh.com,rijndael-cbc@lysator.liu.se
[..]
KeyExchangeList: ecdh-sha2-nistp256,ecdh-sha2-nistp384,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
[..]
HMacList: hmac-sha2-256,hmac-sha2-512,hmac-sha1,hmac-sha1-96

Versions:

• 2026.2 and above
• 2025.2 through 2026.1
• 2024.1.1 through 2025.1
• 2023.1, 2023.2, 2023.3, 2023.4, and 2024.1
• 2022.2, 2022.3, and 2022.4
• 2020.2.6

Notes

• The aes256-ctr encryption algorithm should not be used with hmac-sha1-96. Use hmac-sha1 instead.
• If a device managed by NCM or Hybrid Cloud Availability requires a different set of ciphers/algorithms that are available in the newer release of the product, you will need to upgrade your SolarWinds Platform. Please see the SolarWinds Platform Products Installation and Upgrade Guide for details.

Versions 2026.2 and above

Key Exchange algorithms

• mlkem768x25519-sha256
• curve25519-sha256
• curve25519-sha256@libssh.org
• ecdh-sha2-nistp521
• ecdh-sha2-nistp384
• ecdh-sha2-nistp256
• diffie-hellman-group18-sha512
• diffie-hellman-group16-sha512
• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group14-sha1
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-ed25519
• ecdsa-sha2-nistp256
• ecdsa-sha2-nistp384
• ssh-rsa
• ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• aes128-gcm
• 3des-cbc
• aes192-ctr
• aes192-cbc
• >aes192-gcm
• aes256-ctr
• aes256-cbc
• aes256-gcm
• blowfish-cbc (for no FIPS)
• chacha20-poly130
• rijndael-cbc

MAC algorithms

• hmac-sha2-256-etm@openssh.com
• hmac-sha2-256
• hmac-sha2-512-etm@openssh.com
• hmac-sha1-etm@openssh.com
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96
• mac-md5

Versions 2025.2 through 2026.1

Key Exchange algorithms

• diffie-hellman-group18-sha512
• ecdh-sha2-nistp384
• ecdh-sha2-nistp256
• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group14-sha1
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-ed25519
• ecdsa-sha2-nistp256
• ecdsa-sha2-nistp384
• ssh-rsa
• ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• aes128-gcm
• 3des-cbc
• aes192-ctr
• aes192-cbc
• aes192-gcm
• aes256-ctr
• aes256-cbc
• aes256-gcm
• blowfish-cbc (for no FIPS)
• chacha20-poly130
• rijndael-cbc

MAC algorithms

• hmac-sha2-256-etm@openssh.com 
• hmac-sha2-256
• hmac-sha2-512-etm@openssh.com
• hmac-sha1-etm@openssh.com
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96
• hmac-md5

Versions 2024.1.1 through 2025.1

Key Exchange algorithms

• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1
• diffie-hellman-group14-sha1
• ecdh-sha2-nistp256
• ecdh-sha2-nistp384
• ext-info-c

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-ed25519
• ecdsa-sha2-nistp256
• ecdsa-sha2-nistp384
• ssh-rsa,ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• aes128-gcm
• 3des-cbc
• aes192-ctr
• aes192-cbc
• aes192-gcm
• aes256-ctr
• aes256-cbc
• aes256-gcm
• blowfish-cbc (for no FIPS)
• chacha20-poly130
• rijndael-cbc

MAC algorithms

• hmac-sha2-256-etm
• hmac-sha2-256
• hmac-sha2-512-etm
• hmac-sha1-etm
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96

Versions 2023.1, 2023.2, 2023.3, 2023.4, and 2024.1

Key Exchange algorithms

• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1
• diffie-hellman-group14-sha1
• ecdh-sha2-nistp256
• ecdh-sha2-nistp384
• ext-info-c

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-rsa
• ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• 3des-cbc
• aes192-ctr
• aes192-cbc
• aes256-ctr
• aes256-cbc
• blowfish-cbc (for no FIPS)
• chacha20-poly130
• rijndael-cbc

MAC algorithms

• hmac-sha2-256
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96
• hmac-md5
• none

Versions 2022.2, 2022.3, and 2022.4

Key Exchange algorithms

• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1
• diffie-hellman-group14-sha1
• ecdh-sha2-nistp256
• ecdh-sha2-nistp384
• ext-info-c

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-rsa
• ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• 3des-cbc
• aes192-ctr
• aes192-cbc
• aes256-ctr
• aes256-cbc
• blowfish-cbc (for no FIPS)
• chacha20-poly130
• rijndael-cbc

MAC algorithms

• hmac-sha2-256
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96
• hmac-md5
• none

Version 2020.2.6

Key Exchange algorithms

• diffie-hellman-group14-sha256
• diffie-hellman-group-exchange-sha256
• diffie-hellman-group-exchange-sha1
• diffie-hellman-group1-sha1
• diffie-hellman-group14-sha1
• ecdh-sha2-nistp256
• ecdh-sha2-nistp384
• ext-info-c

Server Host algorithms

• rsa-sha2-512
• rsa-sha2-256
• ssh-rsa,ssh-dss

Encryption algorithms

• aes128-ctr
• aes128-cbc
• 3des-cbc,blowfish-cbc
• aes192-ctr,aes192-cbc
• aes256-ctr,aes256-cbc
• chacha20-poly1305
• rijndael-cbc

MAC algorithms

• hmac-sha2-256
• hmac-sha2-512
• hmac-sha1
• hmac-sha1-96