Since updating to Yosemite, ssh from my Mac to a DNS alias takes about 7-8 seconds.
I've observed the following on multiple Macs running Yosemite. Assume I have a host name alpha, and a DNS alias to it named aa. The OS of the target doesn't matter.
1) ssh to an unqualified host name alias (CNAME record in DNS), e.g. ssh aa, takes about 7-8 seconds to connect
2) immediately repeating the same ssh command, ssh aa, connects in the "normal" amount of time (< 1s)
3) ssh to a fully qualified host name alias, e.g. ssh aa.example.com, connects in the normal amount of time
4) ssh to a regular host name (A record in DNS), e.g. ssh alpha.example.com, whether qualified or unqualified, connects in the normal amount of time.
When using ssh -vvv, the total delay is in one place:
$ ssh -vv aa OpenSSH_6.2p2, OSSLShim 0.9.8r 8 Dec 2011 debug1: Reading configuration data /etc/ssh_config debug1: /etc/ssh_config line 20: Applying options for * debug2: ssh_connect: needpriv 0 *delay of 7-8 seconds* debug1: Connecting to aa [10.10.1.2] port 22. debug1: Connection established. ...
There is no difference in output between any of the 4 scenarios, except for the host name displayed.
This has happened on every release of Yosemite to the current version 10.10.3.
I have searched the web many times, and not found a single reference to this problem. Ideas?