User`s manual

IA260-261-262 EM-2260 LX User’s Manual Managing Communications
Telnet / FTP
In addition to supporting Telnet client/server and FTP client/server, the
IA260/IA261/IA262/EM-2260 also supports SSH and sftp client/server. To enable or disable the
Telnet/ftp server, you first need to edit the file
/etc/inetd.conf .
Enabling the Telnet/ftp server
The following example shows the default content of the file /etc/inetd.conf. The default is to
enable the Telnet/ftp server:
discard dgram udp wait root /bin/discard
discard stream tcp nowait root /bin/discard
telnet stream tcp nowait root /bin/telnetd
ftp stream tcp nowait root /bin/ftpd -l
Disabling the Telnet/ftp server
Disable the daemon by typing ‘#’ in front of the first character of the row to comment out the line.
DNS
The IA260/IA261/IA262/EM-2260 supports DNS client (but not DNS server). To set up DNS
client, you need to edit three configuration files:
/etc/hosts, /etc/resolv.conf, and
/etc/nsswitch.conf.
/etc/hosts
This is the first file that the Linux system reads to resolve the host name and IP address.
/etc/resolv.conf
This is the most important file that you need to edit when using DNS for the other programs. For
example, before you use #ntpdate time.nist.gov to update the system time, you will need to add the
DNS server address to the file. Ask your network administrator which DNS server address you
should use. The DNS server’s IP address is specified with the “nameserver” command. For
example, add the following line to /etc/resolv.conf if the DNS server’s IP address is 168.95.1.1:
nameserver 168.95.1.1
10.120.53.100 – PuTTY
root@Moxa:/etc# cat resolv.conf
#
# resolv.conf This file is the resolver configuration file
# See resolver(5).
#
#nameserver 192.168.1.16
nameserver 168.95.1.1
nameserver 140.115.1.31
nameserver 140.115.236.10
root@Moxa:/etc#
/etc/nsswitch.conf
This file defines the sequence to resolve the IP address by using /etc/hosts file or /etc/resolv.conf.
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