[OpenIndiana-discuss] Slow ssh login?

[Gary Gendel]

Well, my problem seems to be exactly opposite.  If I restart sshd, I get 
really good response at first and then it deteriorates to a several 
second login delay. dig and dig -x is always fast. I even disabled 
reverse DNS on sshd with no difference.  Every once in a while I get 
fast response.  The sshd debug output doesn't show anything 
interesting.  This has been a real head-scratcher.

On 10/19/12 7:02 PM, Richard Elling wrote:
> On Oct 19, 2012, at 3:51 PM, "Dan Swartzendruber" <dswartz at druber.com> wrote:
>
>> Hi, all.  I've got an issue that is bugging me.  I've got an OI 151a7 VM and
>> ssh to it takes 15 seconds or so, then I get a prompt.  It's not the usual
>> reverse dns or gssapi stuff, since my backup node is also OI 151a7 and it
>> responds instantly to the ssh request.
> 15 seconds is a magic number -- the default timeout for a DNS lookup.
> Use getent to verify that lookups (forward and reverse) are fast. Use nscd -i
> to make sure the cached name lookups are flushed.
>
> Another quick test, if the first ssh takes a while, but soon afterwards a second
> completes quickly, then the nscd cache is working properly.
>   -- richard
>
>
>>   Google has not turned up anything
>> useful except for the usual suspects that are innocent in this case.  The
>> only hint I can see is if I give '-v' on the client, I see this:
>>
>> OpenSSH_5.9p1 Debian-5ubuntu1, OpenSSL 1.0.1 14 Mar 2012
>> debug1: Reading configuration data /etc/ssh/ssh_config
>> debug1: /etc/ssh/ssh_config line 19: Applying options for *
>> debug1: Connecting to nas [10.0.0.4] port 22.
>> debug1: Connection established.
>> debug1: identity file /home/dswartz/.ssh/id_rsa type -1
>> debug1: identity file /home/dswartz/.ssh/id_rsa-cert type -1
>> debug1: identity file /home/dswartz/.ssh/id_dsa type -1
>> debug1: identity file /home/dswartz/.ssh/id_dsa-cert type -1
>> debug1: identity file /home/dswartz/.ssh/id_ecdsa type -1
>> debug1: identity file /home/dswartz/.ssh/id_ecdsa-cert type -1
>> debug1: Remote protocol version 2.0, remote software version Sun_SSH_1.5
>> debug1: no match: Sun_SSH_1.5
>> debug1: Enabling compatibility mode for protocol 2.0
>> debug1: Local version string SSH-2.0-OpenSSH_5.9p1 Debian-5ubuntu1
>> debug1: SSH2_MSG_KEXINIT sent
>> (the delay is here)
>> debug1: SSH2_MSG_KEXINIT received
>> debug1: kex: server->client aes128-ctr hmac-md5 none
>> debug1: kex: client->server aes128-ctr hmac-md5 none
>> debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
>> debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
>> debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
>> debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
>> debug1: Server host key: RSA 8c:78:a0:17:6b:17:1b:bf:83:69:a3:bf:59:df:18:07
>> debug1: Host 'nas' is known and matches the RSA host key.
>> debug1: Found key in /home/dswartz/.ssh/known_hosts:9
>> debug1: ssh_rsa_verify: signature correct
>> debug1: SSH2_MSG_NEWKEYS sent
>> debug1: expecting SSH2_MSG_NEWKEYS
>> debug1: SSH2_MSG_NEWKEYS received
>> debug1: Roaming not allowed by server
>> debug1: SSH2_MSG_SERVICE_REQUEST sent
>> debug1: SSH2_MSG_SERVICE_ACCEPT received
>> debug1: Authentications that can continue:
>> publickey,password,keyboard-interactive
>> debug1: Next authentication method: publickey
>> debug1: Trying private key: /home/dswartz/.ssh/id_rsa
>> debug1: Trying private key: /home/dswartz/.ssh/id_dsa
>> debug1: Trying private key: /home/dswartz/.ssh/id_ecdsa
>> debug1: Next authentication method: keyboard-interactive
>>
>> Any thoughts where to look?  It's got to be something that is different
>> between the two OI hosts, but offhand, I'm not sure where to look.
>> Thanks...
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>> OpenIndiana-discuss at openindiana.org
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> --
>
> Richard.Elling at RichardElling.com
> +1-760-896-4422
>
>
>
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