-
8/9/2019 Protecting From Network Threats
1/4
-
8/9/2019 Protecting From Network Threats
2/4
Group wnfaqmufxm;&efjzpfonf/ wpfOD;csif;tvdkuf OD;pGmUser
Account rsm; wnfaqmuf &rnf/ Permissions ^ Rights ( Read, Write,
Execute, Modify, Full Control ) rsm;aqmifGuf ay;&rnf/ ,if; User
Account wlnDolrsm;udkNetwork Operating Systems rsm;rS
oabmwlnDpkzGJYxm;jcif;tm; aygif;pyf^yl;aygif;onf(Combined
)[kac:onf/ xdkodkYUser rsm;rS
Data t&if;tjrpfrsm; tm;
0ifa&mufoHk;pGJEdkifjcif;udkEffective
Permissions [kac:ygonf/Network Operating system rsm;onf
Organization - based Security aqmifGufEdkifygonf/ ,if;udk
Organizational Unit (OU ) [kac:ygonf/ Windows 2000 Server, Windows
2003
Server wdkY jzpfNyD;Computers, Groups, Printers, Users, Shared
Resources rsm;tm; wpfck wnf;wGifBig Directory Tree
tjzpfwnfaqmufxm;Edkifygonf/ Active Directory Users and
Computers [kvnf;ac:ygonf/ xdkodkY aqmifGufjcif;onf MuD;rm;aom
pDrHcefYcGJrIjzpfayonf/ ,cifNetwork
Size MuD;rm;vmaomfvnf;One Big Directory Tree wGifxm;Sdjcif;jzifh
us,fjyefYMu
vmjcif;rSday/Organizational Unit onf xdkodkYtajctaersm;tm;
taxmuftuljyK&efTool yifjzpfygonf/ Organizational Unit onf Users
ESifhGroups rsm;twGuf odrf;qnf;&efae&m
wpfcktjzpfomaqmifGufjcif;jzpfNyD;Rights ^ Permissions rsm;twGuf
&,lEdkifjcif;rSdyg/
Policies
Policy onf User Account, Computer, Group odkYr[kwfOrganizational
Unit rsm;twGuf rsm;pGmtaxmuftyHhjzpfygonf/ odkYaomf(Network
Operating System rsm;ay:wGifwnfrSD
aqmifGuf&jcif;jzpfygonf/Windows 2000 System rsm;ay:wGifLocal
Policies rsm;toHk;jyKyg u Local Security Settings [kac:ygonf/
Protecting a Network from External Threats
Physical Protection
xdkodkUaqmifGuf&mwGif
tydkif;(2)ydkif;jzifhaqmifGufygonf/Servers Site ESifhClients
Site [laqmifGufEdkifygonf/Server ydkif;aqmif&Guf&mwGif
vG,fulpGmaqmifGuUnauthorized Person rsm;twGufLock up
wm;jrpfumuG,faqmifGufxm;&efomjzpfo BuD;rm;aom
tzGJUtpnf;rsm;wGifSpecial Server Room rsm;tjzpfwnf&SdNyD;
jynfhpkHaomCard -
Key Locks rsm;jzifhaqmifGufxm;ygonf/ 0if^xGuf
aqmifGufolrsm;udkvnf; p apmifhMunfhaompepfxm;&Sdygonf/
ao;i,faomtzGJUtpnf;rsm;wGif tNrJwapydw umuG,fxm;ygonf/
rarhravsmhaqmifGuf&efrSmNetwork Switches rsm;\
vkHNcHKa&;jzpf onf/ Hackers rsm;onf Network
twGif;0ifa&mufEdkif&efrSm ,if;Switches yifjzpfojzifh
tvG,fwulcsdwfqufr&Edkif&ef umuG,fxm;&rnfjzpfonf/Server
Protection aqmifGuf&m
wGif wpfcgw&HTechs onf Server Log in aqmifGufxm;csdefwGif
ta0;a&mufaew ojzifh Screensaver tm; Password Protected
aqmifGufxm;&onf/
-
8/9/2019 Protecting From Network Threats
3/4
Clients ydkif;aqmifGuf&mwGifcufcJaomfvnf;Users rsm;rS
tcsdKUaomPhysical Security rsm;udkaqmifGufEdkifayonf/
yxraqmif&Guf&efrSmScreenSaver Password rsm; tokH;jyK&
rnfjzpfonf/ Hacker rS Network twGif;0ifa&muf&ef
BudK;yrf;rI&,lEdkifrnfr[kwfay/ tcsuftaejzifh
okH;pGJaompmGufpmwrf;rsm;tm; rvdktyfonfhtcgtvG,fwultrdIu
pGefUypfonfhtavhtxr&Sdap&ef ESifh
tydkif;tprsm;tjzpfjzwfawmufypfEdkifaomPaper Shedder
xm;&Sd&efvdktyfygonf/ aemufqkH;tcsuftaejzifh
kH;cef;wpfcktwGif;0ifa&m rsm;zGifhMunfhygu t0ga&mifSticky
Notes jzifhUser names ESifhPasswords rsm;tm;awGU&
avh&Sdygonf/Users rsm;taejzifhNote Down aqmifGufygu
vkHNcHKpGmaomhcwf &ayonf/
FireWalls Firewall onf Network tm; umuG,fEdkif&ef
enf;vrf;rsKd;pkHjzifhtokH;jyK
Hiding IP Adresses ESifhBlocking TCP/IP Ports rsm;jzpfygonf/
1. Hiding IP AdressesNetwork rsm;udk umuG,f&ef
trsm;qkH;tokH;jyKaomenf;ynmrSmInternal Network
twGif;wGif trSefwu,ftokH;jyKaeaomReal IP rsm;tm;Internet
rSrjrifap&efHide vkyf xm;jcif;jzpfygonf/Hacker onf Real IP
&&SdyguNetwork System tm; vG,fulpGm&SmazG
EdkifrnfjzpfojzifhReal IP rsm;tm;rjrifEdkif&efHide
vkyfxm;jcif;jzpfonfHacking Techniques rsm;twGuftvG,fulqkH;
umuG,fwm;qD;EdkifrIyifjzpfygonf/ xdkodkUaqmifGufNetwork Address
Translation (odkUr[kwf)Proxy Server rSwqifhInternal Network
wnfaqmuf&ef
jzpfygonf/ Network Address Translation ESifhProxy Server tm;
rnfonfudkaqmifGuf&ef aG;cs,f&onfrSm okH;pGJrnfhNetwork
ay:rIwnfaG;cs,f&onf/ tb,faMumifhqdkaomf wpf csif;pDwGif&Sd
pGrf;aqmif&nfrsm;wGif aumif;usKd;^qdk;usKd;rsm; ,SOfwGJ
onf/
NATs onf IP Addresses udkTranslate
vkyfjcif;omaqmifGufjcif;jzpfNyD;TCP Ports odkUr[kwfInformating
ESifhvkH;0roufqdkifay/Proxy Server onf Port Number ajymif;vJjcif;
ESifhReal IP Address tm; Hide vkyfjcif;aqmifGufEdkifonf/
xdkodkUProxy Server okH;pGJjcif;jzif
Security Level jrifhrm;oGm;rnfjzpfaomfvnf;
wefzdk;jrifhrm;oGm;rnfjzpfonf/ ,if aMumifhNetworks rsm;onf NATs
udkomokH;pGJavh&Sdygonf/Proxy Server onf Web Service om
aqmifGufEdkifNyD;Port ESifhIP ajymif;vJwdkif;Network
twGif;&SdClient Application rsm;Update aqmifGufay;&onf/
2. Port Filtering
'kwd,tokH;trsm;qkH;Firewall Tool rSmPort Filtering jzpfonf/ Port
Blocking [k vnf;ac:ygonf/ Hackers rsm;onf
pkaygif;okH;pGJvQuf&Sdonfhtenf;i,faomPort rsm;rS
0ifa&muf&efBudK;yrf;avh&Sdygonf/Port Filtering
qdkonfrSm rnfonfhTCP odkUr[kwfUDP
Packets onf rvdktyfonfh Port rsm;odkUjzwfoef;jcif;rS
wm;qD;umuG,fNyD; okH;vdPort wpfckodkUomoGm;&efSystem
Administrator rSaqmifGufay;jcif;jzpfonf/Port Filtering onf
-
8/9/2019 Protecting From Network Threats
4/4
rsm;pGmxda&mufrI &Sdygonf/
odkUaomfvkyfief;aqmifGuf&mwGif qDavQmConfiguration
tm;tav;teufxm;jyKvkyf&efvdktyfygonf/
rnfolrqdkjyoemr&SdEdkifonfrSmWell - Known
Port rsm;jzpfonfh80(HTTP) ? 20/21(FTP) ? 25(SMTP) ? 110(POP)
jzpfNyD; tNrJwap xdktenf;i,faom Lesser-known ports rsm;onfNetwork
rsm;wGifyGifhaewwfygonf/
rMumrDu rdrd\Personal Firewall twGif; Port Filtering
udkwnfaqmufcJh&m t&m&m
aumif;rGefpGmvkyfaqmifEdkifcJhygonf/ rdrdrSInternet Game
jzpfonfhHalf - Life udk upm;&ef qkH;jzwfcJh&m ,if;Game
wGifvdktyfaomTCP ports rsm;jzpfaom27010 ESifh27015 rsm;
Internet ay:wGif yGifhaernfjzpfygonf/ xdktjyifMicrosoft
Netmeeting tokH;jyKvdkyguPorts 389 ? 522 ? 1503 ? 1720 ESifh1731
wdkUyGifhrSomaqmifGufEdkifrnfjzpfygonf/
aom Ports rsm;rS0ifa&mufvmEdkifojzifh
apmifhMuyfMunfhIae&rnfjzpfonf/ x udk netstat - an command
jzifhMunfhIUEdkifygonf/Linux wGifIPFILTER/NETFILTER jzifh
Firewall \vkyfaqmifcsufrsm;udkMunfhIEdkifonf/
aemufydkif;Garteway Router rsm;onf NAT ESifhPort Filtering
ESpfckvkH;udk wpfN wnf;aqmifGufvmEdkifNyDjzpfygonf/
3. Packet Filtering
Port Filtering onf Port Number rsm;udkomqufqHaqmifGufNyD;IP
Address tm; vkH;0 tav;*krjyKay/IP Packet
rsm;0ifa&mufvmjcif;udkFiltered vkyfxm;aomPort Number
rsm;ESifhawGUygu ,if;Packet rsm;Block jzpfoGm;rnf/IP Address tm;
tav;*kjyKjcif; awmhr[kwfay/Packet Filtering onf IP Address
wpfckwnf;om apmifhMunfhjcif;jzpfon
xdkaMumifhPacket Filtering udkIP Filtering [kvnf;odMuNyD;
owfrSwfxm;aomIP odkUr[kwfIP Address Range twGif;
0ifvmaom^xGufoGm;aomPacket rsm;tm;Block vkyfEdkifygonf/Packet
Filtering onf Outgoing IP Address rsm;tm;Block vkyf&efNetwork
Administrator rSInternal System rsm;jzpf odNyD;Specific IP
rsm;udkaqmif&Guf&ojzifh usefonfxufFiltering
vkyf&jcif;ydkrdkaumif;rGefygonf/Internet 0ifa&muf&ef
wm;jrpfxm;aomUsers rsm;twGufOutgoing Packet rsm;tm;Block
vkyfxm;jcif;onf aumif;rGefaomenf;vrf;wpfckjzpfygonf/
