slow ssh connection

If you are experiencing slow ssh connections, then possibly your system is trying to do reverse lookup of the IP address. If that is the case, then you can add the below to “hosts” line in /etc/nsswitch.conf file.

‘[NOTFOUND=return]’

The other cause for slow connections can be GSSAPI authentication. If that is the case, then the simplest solution is to add the following in your “~/.ssh/config” file:

GSSAPIAuthentication no

 

Enhanced by Zemanta

Allow incoming/outgoing ports on iptables

Schematic for the packet flow paths through Li...
Schematic for the packet flow paths through Linux networking and Xtables (Photo credit: Wikipedia)

Last couple of years, I just used to disable iptables on my system, this time I decided not to disable it and keep it enabled.

So far so good, now comes the tricky part, I have http server enabled on my system and since this is on local network with already firewall and other security in place so I can allow all incoming to my system and similarly I need to enable XDMCP outgoing. So, I can add the rules like this :

iptables -A INPUT -p tcp –dport 22 -j ACCEPT
iptables -A OUTPUT -p udp -s 0/0 -d 0/0 --dport 177 -j ACCEPT for XDMCP

This works only till I reboot my system and is not persistent. Okay, so I can put this in rc.local file. But why I should do that, there should be more elegnant way. So, I searched and finally found that I can simply put the rules in /etc/sysconfig/iptables as follows:

-A INPUT -p tcp –dport 22 -j ACCEPT
-A OUTPUT -p udp -s 0/0 -d 0/0 --dport 177 -j ACCEPT for XDMCP
Enhanced by Zemanta

unable to browse windows network with samba4

I use Fedora 17 on my work laptop and thus need to connect to windows share sometimes. After I upgraded to Fedora 17 some time, I was unable to browse the windows network. I would get all kind of errors and warnings and tried everything that I knew about Samba to fix the issue. Tried searching through all the forums to figure out what was wrong but nothing helped. And suddenly today I resolved it and guess how:

Samba4 packages still are not able to mount the windows shares.

So, the solution was simple, remove samba 4 and go back to samba 3 current version in the repos. That sounded easy, until I started doing it. There are lot of dependencies on the samba-client so unless you are ready to remove them all and add them again, it’s not going to be that easy. Finally I had to do it the old fashioned way, using rpm command rather that yum, and here is how I did it:

rpm -e --nodeps samba4*
sudo yum install samba*

Since, I wanted all the samba4 packages to go away so removed them all at one go and then added the samba packages with yum :).

Enhanced by Zemanta