Moxa ioPAC 5542-C-T — настройка портов и PPP для удаленного доступа в сети [34/52]

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ioPAC RTU Software RTU Communications

4-9

Port Forwarding (DNAT)

Port forwarding allows remote computers (e.g., computers on the Internet) to connect to a specific computer

or service within a private local-area network (LAN). The following is an FTP port forwarding example.

echo 1 >/proc/sys/net/ipv4/ip_forward

modprobe ip_tables

modprobe nf_conntrack

modprobe nf_conntrack_ftp

modprobe nf_conntrack_irc

modprobe iptable_nat

modprobe nf_nat_ftp

modprobe nf_nat_irc

iptables -t nat -A PREROUTING -p tcp --dport 99 -i eth0 -j DNAT --to-destination 192.168.126.100:

PPP Dial-up Service

PPP (Point to Point Protocol) is used to run IP (Internet Protocol) and other network protocols over a serial link.

PPP can be used for direct serial connections (using a null-modem cable) over a Telnet link, and links

established using a modem over a telephone line.

Modem/PPP access is almost identical to connecting directly to a network through the ioPAC RTU controller

Ethernet port. Since PPP is a peer-to-peer system, the ioPAC RTU controller can also use PPP to link two

networks (or a local network to the Internet) to create a Wide Area Network (WAN).

NOTE

ore information about PPP is available at:

http://tldp.org/HOWTO/PPP

-HOWTO/index.html

http://axion.physics.ubc.ca/ppp

-linux.html

The pppd daemon is used to connect to a PPP server from a Linux system. For more detailed information about

pppd, use pppd --help.