Yes, that was perfect, thx you !
On Wed, Jan 15, 2014 at 5:05 PM, Jay Nugent <[email protected]> wrote: > Greetings, > > > On Wed, 15 Jan 2014, Micka wrote: > > Hi, >> >> I'm curious to know why it takes 10 second to login with ssh when >> /etc/resolv.conf is empty . And when there is something, it takes less >> than >> 1 second to login ! >> > > It is due to DNS lookups and Logging. > > When you log in, a record of your login attempt is logged into > /var/log/secure (or some equivelent log file). The log entry will show the > hostname which you are coming FROM. Hence, a DNS lookup must take place to > resolve the IP address you came from into a fully qualified domain name > (FQDN) - 216.86.85.226 --> k2.nuge.com. > > If /etc/resolv.conf has a 'nameserver' entry, and that DNS server is > indeed reachable and responding to querries, then the DNS lookup and > subsequent logging occurs VERY rapidly. If there is no 'nameserver' entry, > or the listed nameserver is not reachable, then the DNS reverse lookup has > to time out (which takes several seconds), and the log entry will then ONLY > contain the IP address instead of the FQDN. There is your 10 second delay > :( > > If you are not going to have a valid DNS server listed in > /etc/resolv.conf, then I highly recommend that you create a list of the > most common IP addresses you will be SSHing in from, and add them to your > /etc/hosts file. /etc/hosts is tested FIRST before /etc/resolve.conf and > any matching entry there will be used rather than attempt to perform a DNS > lookup. > > So... if you most commonly log in from a couple hosts on your local > LAN, and maybe a workstation at work, entries such as shown below could be > entered into your /etc/hosts file: > > 192.168.1.100 workstation-1 > 192.168.1.101 workstation-2 > 216.86.85.226 PC-at-work > > > Hope this helps, > --- Jay Nugent WB8TKL > Instructor, Washtenaw Community College - Ann Arbor, MI > CIS-121, 206, 208 UNIX/Linux System Administration > > > -- > For more options, visit http://beagleboard.org/discuss > --- You received this message because you are subscribed to the Google > Groups "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/groups/opt_out. > -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
