User's Manual

Chapter 12 Firewall
B222s User’s Guide
106
12.1.2 What You Need to Know
DoS
Denials of Service ( DoS) at tacks are aim ed at devices and networks wit h a connect ion t o t he
I nt ernet. Their goal is not t o steal inform ation, but to disable a device or net work so users no longer
have access to net work resour ces. The ZyXEL Device is pre- configured t o autom atically detect and
thwart all known DoS at tacks.
Firewall
The LTE Device’s firewall feat ure physically separat es the LAN/ WLAN and the WAN and act s as a
secure gateway for all data passing bet w een t he net works.
I t is designed to prot ect against Denial of Serv ice (DoS) at t acks when act ivat ed. The LTE Device's
purpose is to allow a private Local Area Net work ( LAN) t o be securely connected to t he I nt ernet.
The LTE Device can be used t o prevent t heft , dest ruct ion and m odificat ion of dat a, as well as log
events, which m ay be im portant t o t he securit y of your network.
The LTE Device is installed between t he LAN/ WLAN and a broadband m odem connect ing t o t he
I nt ernet. This allows it to act as a secure gateway for all dat a passing bet ween t he I nt ernet and the
LAN.
The LTE Device has one Et hernet WAN port and four Ethernet LAN port s, which are used t o
physically separate the network int o two areas.The WAN ( Wide Area Net work) port at t aches to t he
broadband (cable or DSL) m odem to t he I nternet .
The LAN (Local Ar ea Networ k) port at taches t o a net w ork of com put ers, which needs securit y from
the out side world. These com put ers will have access t o I nt ernet services such as e- m ail, FTP and
the World Wide Web. However, "inbound access" is not allowed ( by default ) unless t he rem ot e host
is aut horized t o use a specific service.
ICMP
I nt ernet Cont rol Message Protocol ( I CMP) is a m essage control and error- report ing prot ocol
bet ween a host ser ver and a gat eway to t he I nternet . I CMP uses I nternet Prot ocol (I P) dat agram s,
but t he m essages are processed by the TCP/ I P soft ware and dir ectly apparent to t he applicat ion
user.
Finding Out More
See
Section 12.6 on page 112 for advanced technical inform ation on fir ewall.