CentOS Linux Server Guide

Telnet and FTP Slow Response To CentOS Linux Server

Possible root cause:

Slow telnet or ftp initial session delay to CentOS Linux Server are usually caused by the Linux Server. The delay was caused by CentOS Linux server is performing reverse DNS lookup to the connecting host. If you are not using DNS lookup or reverse lookup at your local network, you can simplt edit the /etc/host. Add in PC that using telnet/ftp to the server .

Solution: Telnet and FTP Slow Response To CentOS Linux Server

Step1: Edit you nsswitch.conf

vi /etc/nsswitch.conf

Step 2: Check host setting the nsswitch.conf line

Scroll down until you see hosts line. Make sure that you have the following configuration line.

hosts: file dns

This is to tell the CentOS Linux box to lookup at /etc/hosts before perform any DNS lookup.

　

#
# Example:
#passwd: db files nisplus nis
#shadow: db files nisplus nis
#group: db files nisplus nis

passwd: files
shadow: files
group: files

#hosts: db files nisplus nis dns
hosts: files dns

Step3: Edit your /etc/hosts file

Edit your /etc/hosts file.

vi /etc/hosts

Add the your pc-name that need to connect to this CentOS Linux server.

# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 localhost
172.16.1.101 your-pc-name

Now, try to telnet/ ftp again to the server and see the different.

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