Slow diagnosis and resolution of Solaris Linux SSH

1. Use the following steps to diagnose

Ssh-v username@ipaddrssh-vv username@ipaddrssh-vvv username@ipaddr/* found that GSSAPI verification was slow in the verification phase. Use man sshd_config to find the relevant parts of Authentication, and found that GSSAPI authentication can be disabled by setting the following options: / * sshd_config file is the ssh server configuration file, ssh_config is the client configuration file # vi / etc/ssh/sshd_config GSSAPIAuthentication no/* restart ssh service: / * if ssh refuses to connect after restart Generally speaking, sshd_config has options to configure syntax errors. You can use svcs-l ssh to see that you are in maintenance status, modify the configuration, restart the service, and svcadm clear ssh can # svcadm restart ssh.

two。 Found that ssh connection is still slow

/ * next, use the windows wireshark software to capture the network packet, and find that at the moment of slow jam, the server side is doing reverse parsing through DNS client IP/* if it is a Linux client, you can use the tool strace to track the ssh process 8211 7019.583584 192.168.204.244 192.168.204.100 DNS 88 Standard query 0x5755 PTR 100.204.168.192.in-addr.arpa

3. Determine that DNS reverse parsing is slow, disable sshd_config parsing client IP

/ * in Linux, configure UseDNS no in the sshd_config file to disable parsing, and disable it in Solaris using the following configuration: / * you can view the detailed configuration instructions through man sshd_config # vi / etc/ssh/sshd_config LookupClientHostnames no

4. Refer to other possible situations of the network

(1) after entering the password using Kerberos/*, it takes a long time to succeed. Modify / etc/pam.conf file, comment or delete the following entries: other auth sufficient pam_krb5.so.1 (2) when NFS,NFS is not available, it may cause SSH root to be very fast and su very slow