SSH connection from RHEL 6 to RHEL 8(fips) fails with messages "no hostkey alg"

Solution Verified - Updated -


  • SSH from RHEL6 to RHEL8 is failing while running RHEL8 in FIPS mode.
  • Getting below SSH debug output :
debug2: mac_setup: found hmac-sha1
debug1: kex: server->client aes128-ctr hmac-sha1 none
debug2: mac_setup: found hmac-sha1
debug1: kex: client->server aes128-ctr hmac-sha1 none
no hostkey alg
  • SSH interoperability of RHEL8 in FIPS mode.


  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 8
  • openssh

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