[lug] can ping the host, but can't ssh for a few seconds

[Vishal Verma]

Hi,

I was about to suggest the same. Try -vvv for lots of debug, but it
will surely tell you at which point it fails.
You can also look at the server side log, in something like /var/log/auth.log

--
Vishal


On Tue, Jul 10, 2012 at 10:01 AM, Stephen Queen <svqueen at gmail.com> wrote:
> Maybe try the -v option of ssh on the first iteration, see if it gives
> you a hint why it is failing.
> [software at saratoga build-jaws-svn]$ date; ping -c 1 warsaw;
> /sbin/route; ssh -v software at warsaw
>
> Steve
>
> On 7/10/12, Michael Hirsch <mdhirsch at gmail.com> wrote:
>> On Mon, Jul 9, 2012 at 1:29 PM, Ebben Aries <earies at dscp.org> wrote:
>>
>>> You are sending an echo req -> saratoga (localhost eth0 by the looks of
>>> it), yet following that w/ a connection attempt to warsaw - have a look
>>> at
>>> your arp cache for warsaw's address if it is on the same segment or your
>>> gw (192.168.1.1) if not.  Alter your ping statement to target warsaw
>>> rather
>>> to trigger an arp request prior to connection attempt. (which looks like
>>> what you were attempting to do in the first place)
>>>
>>
>> OMG, duh!  Don't know how I did that.  Obviously I should be pinging
>> warsaw.  Thanks for pointing it out.
>>
>> Unfortunately, it still behaves like that.  Here is the output of pinging
>> warsaw, then trying to ssh there.  Then I wait a short time and try again.
>> The second time it connects.  The route hasn't changed.
>>
>> [software at saratoga build-jaws-svn]$ date; ping -c 1 warsaw; /sbin/route;
>> ssh software at warsaw
>> Tue Jul 10 09:15:12 MDT 2012
>> PING warsaw.stirlingsystems.net (192.168.1.21) 56(84) bytes of data.
>> 64 bytes from warsaw.stirlingsystems.net (192.168.1.21): icmp_seq=0 ttl=64
>> time=4.54 ms
>>
>> --- warsaw.stirlingsystems.net ping statistics ---
>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>> rtt min/avg/max/mdev = 4.546/4.546/4.546/0.000 ms, pipe 2
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags Metric Ref    Use
>> Iface
>> 172.16.30.0     *               255.255.255.0   U     0      0        0
>> vmnet8
>> 192.168.137.0   *               255.255.255.0   U     0      0        0
>> vmnet1
>> 192.168.8.0     192.168.1.51    255.255.255.0   UG    0      0        0
>> eth0
>> 192.168.0.0     *               255.255.252.0   U     0      0        0
>> eth0
>> 169.254.0.0     *               255.255.0.0     U     0      0        0
>> eth0
>> default         192.168.1.1     0.0.0.0         UG    0      0        0
>> eth0
>> ssh: connect to host warsaw port 22: No route to host
>> [software at saratoga build-jaws-svn]$ date; ping -c 1 warsaw; /sbin/route;
>> ssh software at warsaw
>> Tue Jul 10 09:15:17 MDT 2012
>> PING warsaw.stirlingsystems.net (192.168.1.21) 56(84) bytes of data.
>> 64 bytes from warsaw.stirlingsystems.net (192.168.1.21): icmp_seq=0 ttl=64
>> time=0.196 ms
>>
>> --- warsaw.stirlingsystems.net ping statistics ---
>> 1 packets transmitted, 1 received, 0% packet loss, time 0ms
>> rtt min/avg/max/mdev = 0.196/0.196/0.196/0.000 ms, pipe 2
>> Kernel IP routing table
>> Destination     Gateway         Genmask         Flags Metric Ref    Use
>> Iface
>> 172.16.30.0     *               255.255.255.0   U     0      0        0
>> vmnet8
>> 192.168.137.0   *               255.255.255.0   U     0      0        0
>> vmnet1
>> 192.168.8.0     192.168.1.51    255.255.255.0   UG    0      0        0
>> eth0
>> 192.168.0.0     *               255.255.252.0   U     0      0        0
>> eth0
>> 169.254.0.0     *               255.255.0.0     U     0      0        0
>> eth0
>> default         192.168.1.1     0.0.0.0         UG    0      0        0
>> eth0
>> software at warsaw's password:
>>
>>
>> Thanks,
>>
>> Michael
>>
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