To fix the issue edit the sshd_config file as mentioned below # cat -n /etc/ssh/sshd_config | grep -i MAcs Their offer: Īug 24 07:15:24 rhellinuxserver sshd: Unable to negotiate with 172.21.112.111 port 33541: no matching MAC found. In centOS/RHEL 7 server while trying to access the server via TMA pulse secure tool and getting the below error on ~]# cat /var/log/secure| grep -iE "no matching"Īug 24 07:02:07 rhellinuxserver sshd: Unable to negotiate with 172.21.112.111 port 16899: no matching MAC found. we take aes128-cbc from the error message and try to connect, and it will be connected $ ssh -c aes128-cbc -A Their offer: aes128-cbc,3des-cbc,aes192-cbc,aes256-cbcĬheck your supported cipher by $ ssh -Q cipher # output would be something now in order to connect to target server with their choice of cipher which your server doesnt support you have to explicitly provide one of the cipher supported by target server. Unable to negotiate with XX.XX.XX.XX port 1234: no matching cipher found. we take hmac-sha2-512 from the error message and try to connect, and it will be connected $ ssh -m hmac-sha2-512 -A Īnother variant of the problem is the mismatch in cipher which looks like below $ ssh -A To see this run in command line on your machine $ ssh -Q mac # output would be something now in order to connect to target server with their choice of mac which your server doesn't support you have to explicitly provide one of the mac supported by target server.
Their root cause of this error is on your source machine the supported MAC doesnt contain the MAC from target server. Unable to negotiate with XX.XX.XX.XX port 1234: no matching MAC found. I was trying to ssh to a target server and getting error like below $ ssh -A Sharing the experience so it can help someone. I have struggled to this problem for decent time before understanding the basics and root cause.