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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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DatagramSocketImplHttpURLConnectionInetAddressMulticastSocketServerSocketSocket
SocketImplURLURLConnectionURLncoderURLStreamHandler
&ce5++
!ind"ceptionConnect"ceptionMal#ormedURL"ception
$oRoute%oHost"ceptionProtocol"ceptionSocket"ceptionUnkno&nHost"ceptionUnkno&nService"ception
Inter#ee
ContentHandler'actor('ile$ameMapSocketImpl'actor(URLStreamHandler'actor(
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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Returneaa adresa e#ectiva repreentat/ de o)iectul respectiv0ntr1un vector de 2 octe+i.Cel mai semni#icativ octet se g/se*te0n getAddress,-*3+."4 *5678 298 :;8 ?d.?d.?d.?d@
"4 >567.29.:;.
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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ers+unea standard de *aKa #ooseLte 5entru +m5ementarea
comun+ca+e+ 5e a\ de cone+un+ 5rotocou 'CP 'ransm+ss+on Contro
5rotoco; unu d+n 5rotocoaee de a\ ae #am++e+ 'CPEIP.
Modu de ucru cu socur+e se ncadrea\ n modeu c+entEserKer de
scr+ere de a5+ca++; mode n care a5+ca++e se m5art n dou\ cate=or++ · 5ro=rame c+ent - cee care +n++a\ conKersa+a
· 5ro=rame serKer - cee care o#er\ serK+c++ 5ro=rameor c+ent
In K+rtutea acestu+ #a5t; or+ce cone+une ntre dou\ 5ro=rame care comun+c\
5r+n reea este determ+nat\ un+c de eemente
1. adresa =ade+ 5e care ruea\ a5+ca+a c+ent
2. num\ru de 5ort a a5+ca+e+ c+ent
3. adresa =ade+ 5e care ruea\ a5+ca+a serKer
. num\ru de 5ort 5e care serKeru 5r+meLte cerer+e
0n socu *aKa 5oate ucra n dou\ modur+ n d+rect - +m5+c+t su#+c+ent 5entru maor+tatea a5+ca++or
n cu #ac++t\+ s5ec+ae 5e socu; #oos+t de a5+ca++e care neces+t\
comun+carea 5este un +d de 5rotec+e #+rewa sau 5r+n
+ntermed+u unu+ serKer 5roD
Im5ementarea unu+ socu c+ent sau serKer se rea+ea\ 5r+n et+nderea
case+ astracte SocketImpl.Metodee aceste+ case 5un a d+5o++e
+nstrumente de comun+ca+e d+rect\. Pentru a crea un socu cu #ac++t\+
s5ec+ae este necesar\ rede#+n+rea metodeeor d+n aceast\ cas\.
Casa SocketImpl
ar+a+e
protected java.io.'ileDescriptor #d%e #ile descriptor o)ject #or tis socket.
protected java.net.InetAddress address
%e IP address o# te remote end o# tis socket.protected int port
%e port num)er on te remote ost to &ic tis socket isconnected.
protected int localport%e local port num)er to &ic tis socket is connected.
Metodeprotected java.io.'ileDescriptor get'ileDescriptor, -protected java.net.InetAddress getInetAddress, -
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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Returnea/ nr de octe+i care pot #i citi+i #/r/ a )loca cone"iuneaprotected a)stract void )ind, java.net.InetAddress ost8 int port -
tro&s java.io.I"ceptionLeag/ cone"iunea de un anumit partener speci#icat prin adresa IPsi port
protected a)stract void close, - tro&s java.io.I"ceptionIncide o cone"iune
protected a)stract void connect, java.net.InetAddress address8 int port- tro&s java.io.I"ceptionRealiea/ o cone"iune cu un anumit partener
protected a)stract void connect, java.lang.String ost8 int port -tro&s java.io.I"ception
protected a)stract void create, )oolean stream - tro&sjava.io.I"ception
protected a)stract void listen, int )acklog - tro&s java.io.I"ceptionSta)ile*te num/rul ma"im de cone"iuni admise
protected native java.lang.)ject clone, - tro&sjava.lang.Clone$otSupported"ception
protected void #inalie, - tro&s java.lang.%ro&a)le
Pro=rame de t+5 c+ent
Casa Socket astract+ea\ no+unea de socu c+ent num+t n
=enera socu L+ este res5onsa+\ de maor+tatea o5era++or necesare
comun+ca+e+ n reea. Pr+n +nstan+erea unu+ o+ect de t+5 Socket;
5ro=ramu c+ent 5oate s\ +n++ee o cone+une 5r+n constructor L+ s\
+m5ementee comun+ca+a 5r+n reea.
/tructura une+ a5+ca++ c+ent aate 5e cone+un+5. Ini+iali/ri6. Are #acilit/+i speciale de soclu F
Da ® Scim)are comportament prin SocketImpl
7. Creare soclu de comunicare *i sta)ilire cone"iune2. )+inere #lu"uri de comunicare cu partenerul9. Prelucr/ri speci#ice aplica+iei client:. ste ultimul utiliator al soclului F
Da ® Incidere soclu;. 'aa #inal/ a e"ecu+iei
Casa Socket
Constructor+protected Socket, -
Creea/ o cone"iune #/r/ nici un partener speci#icatprotected Socket, java.net.SocketImpl impl -
tro&s java.net.Socket"ceptionpu)lic Socket, java.net.InetAddress address8 int port -
tro&s java.io.I"ceptionCreates a socket and connects it to te speci#ied port num)er atte speci#ied IP address.
pu)lic Socket, java.lang.String ost8 int port -tro&s java.net.Unkno&nHost"ception8 java.io.I"ception
pu)lic Socket, java.net.InetAddress ost8 int port8 )oolean stream -tro&s java.io.I"ception
I# te stream argument is true8 tis creates a stream socket. I#te stream argument is #alse8 it creates a datagram socket.
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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java.net.InetAddress getInetAddress, -java.io.InputStream getInputStream, - tro&s java.io.I"ception
)+ine #lu"ul de intrare de la care pot #i citite datele dinacest soclu.
java.net.InetAddress getLocalAddress, -int getLocalPort, -java.io.utputStream getutputStream, - tro&s java.io.I"ception
)+ine #lu"ul de ie*ire prin care pot #i scrise dateleint getPort, -static s(ncronied void setSocketImpl'actor(,
java.net.SocketImpl'actor( #ac - tro&s java.io.I"ception
int getSoLinger, - tro&s java.net.Socket"ceptions(ncronied int getSo%imeout, - tro&s java.net.Socket"ceptions(ncronied void setSo%imeout, int timeout -
tro&s java.net.Socket"ception)oolean get%cp$oDela(, - tro&s java.net.Socket"ceptionvoid set%cp$oDela(, )oolean on - tro&s java.net.Socket"ception
s(ncronied void close, - tro&s java.io.I"ceptionvoid setSoLinger, )oolean on8 int val - tro&s java.net.Socket"ceptionjava.lang.String toString, -
Pro=ramu t+5 serKer
/erKeru este 5ro=ramu care ascut\ cerer+e Ken+te de a c+en+ L+ e o#er\
serK+c+u 5entru care a #ost creat. Ident+#+carea serKereor se #ace 5r+n
+ntermed+u 5ortuu+ 5e care serKeru aLtea5t\ cerer+e de cone+une Ken+te
d+n 5artea c+en+or. Maor+tatea serK+c++or #oarte des #oos+te n Internet au
asoc+ate 5ortur+ standard+ate; 5entru a 5erm+te c+en+or s\ o5eree cu
d+#er+te serKere n Kederea o+ner++ unu+ serK+c+u.
&em5e de numere de 5ortur+ standard+ate
/erK+c+u Port asoc+at
PoLta eectron+c\ 2%
'rans#er de #+L+ere 21
'enet 23
:+n=er "9
8!
&cou "
&ecu+e a d+stan\ reec %12
PP3 Post ##+ce Protoco 11!
Pr+mu ucru 5e care treu+ s\- #ac\ un 5ro=ram serKer este s\ se
asoc+ee 5ortuu+sta++t a momentu 5ro+ect\r++ a5+ca+e+ L+ s\ +n++ee
ascutarea cerer+or de serK+c++ Ken+te de a c+en+. Aceste ucrur+ se
rea+ea\ 5r+n constructoru case+ ServerSocket; casa care +m5ementea\
socu 5ro=ramuu+ serKer.
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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ar=ument a constructoruu+. r+ce cerere nou\ Ka #+ res5+ns\ dac\ num\ru de
cerer+ 5reucrate are Kaoarea ma+m\ s5ec+#+cat\.
/tructura une+ a5+ca++ serKer aate 5e cone+un+5. Ini+iali/ri
6. Are #acilit/+i speciale de soclu FDa ® Scim)are comportament prin SocketImpl
7. Creare soclu server pentru ascultare cereri2. Ascultarea continu/ F
$u ® Incidere soclu'aa #inal/
9. Ascultare cereri cone"iuni:. Acceptare cerere *i o)+inere soclu pentru comunicare;. Creare #ir de e"ecu+ie pentru tratarea cone"iunii
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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In cadru +m5ement\r++ standard *aKa; data=ramee sunt trans5ortate
5r+n reea #oos+nd 5rototcou 0$P 0ser $ata=ram Protoco; unu d+n
5rotocoaee de a\ ae #am++e+ 'CPEIP.
AKantae
·
K+tea de trans#er ma+ mare· ada5tarea a cond+++e de moment ae reee+ con=est++; e=\tur+
tem5orar +nd+s5on++e; etc
$eaKantae ucru ma+ d+#+c+
$+#erena #a\ de comun+carea 5r+ntr-un cana s+=ur o#er+t\ de metoda
comun+ca+e+ 5r+n cone+un+ este c\; #oos+nd data=rame; nu se sta+eLte o
e=\tur\ 5ermanent\ ntre c+ent L+ serKer. $e #a5t; c,+ar no+un+e de c+ent L+
serKer L+ 5+erd semn+#+ca++e; ntrucJt amee #oosesc 5entru comun+care
aceaL+ t+5 de socu; +m5ementat de casa DatagramSocket. C+entu Ka #+
a5+ca+a care nca5suea\ o cant+tate de date cerere ntr-un 5ac,et L+ o
transm+te unu+ 5artener; +ar serKer Ka #+ a5+ca+a care 5r+meLte 5ac,ete de t+5
cerere L+ retr+m+te 5ac,ete cu r\s5unsur+ a cerer+e 5r+m+te. In cau n care
un 5ac,et se 5+erde; c+entu Ka retransm+te cererea du5\ un anum+t +nterKa
de t+m5.
Pentru data=rame nu e+st\ dest+na++ +m5+c+te; aLadar n #+ecare
data=ram\ treu+e s5ec+#+cate
· adresa dest+na+e
· num\ru 5ortuu+ a care se tr+m+te data=rama
· con+nutu data=rame+In *aKa; acese +n#orma++ sunt concentrate n o+ecte de t+5DatagramPacket.
/tructura une+ a5+ca++ aate 5e data=rame5. Ini+iali/ri6. Are #acilit/+i speciale de soclu F
Da ® Scim)are comportament prin DatagramSocketImpl
3. Creare soclu datagrame2. Care este ac+iunea urm/toare F
%ransmisieProducere date
Incapsulare date in pacet%rimitere date
Recep+ieCreare pacet recep+ie dateRecep+ie datePrelucrare date
9. ste ultimul utiliator al soclului F
$u ® G% 2
Da ® Incidere soclu
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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Construie*te un o)iect pentru trimiterea de pacete de lungime ilength spre gada *i portul speci#icate.
Metode
s(ncronied java.net.InetAddress getAddress, -Returnea/ adresa IP la care datagrama este trimis/ sau de lacare a #ost recep+ionat/
s(ncronied void setAddress, java.net.InetAddress iaddr -s(ncronied )(te *+ getData, -
Returnea/ datele care sunt trimise sau care au #ost recep+ionates(ncronied void setData, )(te*+ i)u# -s(ncronied int getLengt, -
Returnea/ lungimea pacetului care va #i trimis sau care a #ostrecep+ionat
s(ncronied void setLengt, int ilengt -s(ncronied int getPort, -
Returnea/ num/rul portului la care datagrama este trimis/ sau dela care a #ost recep+ionat/
s(ncronied void setPort, int iport -
Casa DatagramSocket
Constructor+pu)lic DatagramSocket, - tro&s java.net.Socket"ceptionConstructs a datagram socket and )inds it to an( availa)le port on telocal ost macine.pu)lic DatagramSocket, int port - tro&s java.net.Socket"ceptionConstructs a datagram socket and )inds it to te speci#ied port on telocal ost macine.pu)lic DatagramSocket, int port8 java.net.InetAddress laddr -
tro&s java.net.Socket"ceptionCreates a datagram socket8 )ound to te speci#ied local address. %elocal port must )e )et&een 3 and :9979 inclusive.
Metode
java.net.InetAddress getLocalAddress, -int getLocalPort, -s(ncronied int getSo%imeout, - tro&s java.net.Socket"ceptions(ncronied void setSo%imeout, int timeout -
tro&s java.net.Socket"ception
void close, -s(ncronied void receive, java.net.DatagramPacket p -
tro&s java.io.I"ceptionvoid send, java.net.DatagramPacket p - tro&s java.io.I"ception
16
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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· num\rul de port ; dac\ este d+#er+t #a\ de ce +m5+c+t #oos+t de
5rotoco
· directorul n care se a#\ documentu
· numele fi[ierului n care este 5asat documentu
Ma+ mut; este 5os++\ +dent+#+carea c,+ar a unor sec+un+ d+n documentures5ect+K.
:oos+rea adreseor 0R) se rea+ea\ 5r+n +ntermed+u case+ URL.
Casa URL
Constructor+pu)lic URL, java.lang.String spec -
tro&s java.net.Mal#ormedURL"ception
pu)lic URL, java.lang.String protocol8 java.lang.String ost8 int port8java.lang.String #ile -
tro&s java.net.Mal#ormedURL"ception...
Metode
#inal java.lang.)ject getContent, - tro&s java.io.I"ceptionjava.lang.String get'ile, -java.lang.String getHost, -int getPort, -java.lang.String getProtocol, -java.lang.String getRe#, -static s(ncronied void setURLStreamHandler'actor(,
java.net.URLStreamHandler'actor( #ac -
java.net.URLConnection openConnection, - tro&s java.io.I"ception
#inal java.io.InputStream openStream, - tro&s java.io.I"ception)oolean same'ile, java.net.URL oter -
java.lang.String to"ternal'orm, -java.lang.String toString, -
18
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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-neomo=eneAvantajele folosiri reţelelor sint: -folosirea in coun a resurselor fi!ice -#oos+rea +n comun a dateor
In functie de aria de raspindire a calculatoarelor dintr-o retea exista
urmatoarele tipuri de retele:
- retele locale (lan)
-retele netropolitane (man)
-retele globale (wan)
Pentru o mai buna functionare a reţelelor de calculatoare s-au adoptat anumite
standarde de retea care trebuie respectate de toate calculatoarele.
Pentru realizarea unei retele sin necesare componente hardwere sau
softwere.
Componente hardwere
-calculatoare (nod de retea)
-cabluri de transmisie
-echipamente specifice retelei: adaptoare de retea! modemuri!dispziti" de
atasare la mediu!concentratoare!repetoare!puntile!porti!routere
Componente softwere se refera la sisteme de operare al retelei si la
programele de aplicatie tip retea.
#istemu de operare al retelei numit $%# este o colectie de programe prin
care se controleaza modul de parta&are a resurselor reţelelor.In nodurile
retelei putem a"ea #er"ere sau stati de lucru.
#er"erele sin calculatoarele cu capacitate mare de stocare a informatiilor pe
un disc sau un grup de discuri la care au acces celelalte calculatoare din retea
. #er"erele asigura ser"icii de tiparire si ser"icii de comunicare. #tatiile de
lucru sint calculatoare la care au acces ser"erele din retea. Pot fi unitati de
discuri si fara unitati de discuri.'eţelele pot fi de fisiere sau retele de la egal la egal.
in punct de "edere al modului de lucru putem a"ea
-cu ser"er dedicat
-cu ser"er ne dedicat
% retea de calculatoare este caracter de topologie mediul fizic de transmisie
si standartul de transport.#e pot defini topologii
-o topologie fizica care se refera la modul in care sint legate din punct de
"edere calculatoarele.
-o topologie logica care se refera la modul in care sunt transferate datele.
in punct de "edere al topologiei fizice putem a"ea retele liniare
!inel!stea!stea cu inel.
2!
C
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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. Introducere
NA' 'ransatarea Adreseor de Retea; 5recum s+ acest H' Ka #+ un =,+d reat+K s+=ur 5entru kerne2..! s+ ma+ mut.
In +nu 2.; s-a +ntrodus o +n#rastructura 5t. manu+rea 5ac,eteor; num+ta Bnet#+terB. 0n n+Ke sau strat
deasu5ra aceste+ structur+
da 5os+++tatea de NA'; com5et re+m5ementat d+n kerneee anter+oare.
c 2!!! Pau BRustDB Russe. )+centa su
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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/NA' se #ace +ntotdeauna du5a routare P/'R0'IN
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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U Adau=a o re=ua +na+nte de routare -A PR&R0'IN
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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192.168.1.!E2 sau 192.168.1.!E2%%.2%%.2%%.!.
Pot+ s5ec+#+ca +nter#ata 5e care K+n B-+B sau B--+n-+nter#aceB sau cea 5e care 5eaca B-oB sau B--out-+nter#aceB
5entru care se
ca 5otr+K+; dar +nter#ata s5ec+#+cata de5+nde de antu a care este 5usa re=ua 5entru PR&R0'IN< se
5oate s5ec+#+ca numa+ +nter#ata
5e care K+n 5ac,etee; +ar 5entru P/'R0'IN< s+ 0'P0' cea 5e care 5eaca 5ac,etee. $aca #oosest++nter#ata =res+ta; +5taes Ka da
o eroare.
%.2 Puntce #+ne +n a seecta ce 5ac,ete sa atere+
Am s5us ma+ sus ca 5ot+ s5ec+#+ca o adresa 5entru sursa s+ dest+nat+e. $aca om+t+ o5t+unea 5entru 5entru
adresa surse+; atunc+ or+ce
sursa Ka #+ #oos+ta. Anao= se Ka +ntam5a s+ 5entru adresa dest+nat+e+.
Pot+; de at#e; sa +nd+c+ s+ un 5rotoco anume B-5B sau B--5rotocoB; cum ar #+ 'CP sau 0$PZ numa+ 5ac,etee
de acest t+5 se Kor
5otr+K+ re=u++. Mot+Ku 5r+nc5a 5entru care se #ace acest ucru; este ca atunc+ cand se s5ec+#+ca 5rotocou se
5ot #oos+
o5t+un+ +n 5us; s5e#+c+ce #++nd B--source-5ortB s+ B--dest+nat+on-5ortB areK+ate ca B--s5ortB s+ B--d5ortB.
Aceste o5t+un++ te asa sa s5ec+#+c+ ca numa+ anum+te 5ac,ete cu o anum+ta sursa s+ dest+nat+e se Kor 5otr+K++
re=u++. Acesta
este #oos+tor 5entru a red+recta cerer+e we 'CP; 5ort 8! sau 8!8! s+ a asa ceeate 5ac,ete +n 5ace.
Aceste o5t+un+ treu+e sa #+e du5a B-5B care are ca e#ect secundar +ncarcarea +rar+e 5entru ace 5rotoco.
Pot+ #oos+
numeree 5ortur+or sau un nme d+n #+s+eru EetcEserK+ces.
'oate ca+tat+e d+#er+te 5e care e 5ot+ seecta 5t. un 5ac,et sunt deta+ate +n 5a=+n+e de manua man
+5taes.
6. Cum se atereaa 5ac,etee
$ec+; acum st+m cum sa seectam 5ac,etee 5e care Krem sa e ateram. Pentru a com5eta re=ua treu+e sa-+
s5unem kerneuu+
eact ce Krem sa #acem cu 5ac,etee.
6.1 NA' 5t. sursa /NA'
re+ sa #ac+ /NA'Z sc,+ma adresa surse+ cone+un+or a ceKa d+#er+t. Acest ucru se #ace +n antu
P/'R0'IN
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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Nu treu+e sa 5u+ e5+c+t +n sursa adresa sursa cand #ac+ masOuerad+n=; Ka #oos+ adresa sursa a +nter#ete+ 5e
care 5ac,etu
+ese a#ara. $ar; ce ma+ +m5ortant este ca;daca e=atura 5+ca; cone+un+e care sunt 5+erdute or+cum sunt
u+tate; +nsemnand
ma+ 5ut+ne 5roeme daca ; cone+unea +s+ reK+ne; dar cu un at +5.
UU :acem masOuerad+n= a tot ce +ese 5e 555!. U +5taes -t nat -A P/'R0'IN< -o 555! - MA/V0&RA$&
6.2 NA' 5t. dest+nat+e $NA'
Acest ucru este #acut +n antu PR&R0'IN
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
------------------------------------------------------------------------------------
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+nseamna ca nu Ka rema5a 5ortur+e decat +n cau +n care nu are de aes.
Ma5area +m5+c+ta a 5ortur+or sursa
C,+ar s+ atunc+ cand 5entru o cone+une nu este necesar NA'; transatarea 5ortuu+ sursa 5oate aKea oc
+m5+c+t; daca o cone+une
a #ost ma5ata 5este o noua cone+une. /a cons+deram cau 5entru masOuerad+n=; #++nd un ucru o+snu+t.
1. cone+une we se sta+este de 5e o mas+na 192.1.1.1 5e 5ortu 1!2 a www.netsca5e.com 5e
5ortu 8!.
2. Aceasta adresa este masOueradata de mas+na cu +5-u 1.2.3. 5entru a #oos+ adresa IP a+ e+ ca sursa.
3. Mas+na care #ace masOuerad+n= Ka +ncerca sa sta+easca o cone+une we a www.netsca5e.com
5ort 8! de a 1.2.3. adresa
+nter#ete+ eterne 5ortu 1!2.
. Codu NA' Ka atera 5ortu sursa a a doua cone+une a 1!2%; ast#e +ncat cee 2 cone+un+ sa nu se
oKeasca.
Cand are oc ma5area +m5+c+ta a surse+; 5ortur+e sunt +m5art+te +n 3 cate=or++
Q Portur+ su %12
Q Portur+ +ntre %13 s+ 1!23 Q Portur+ de a 1!2 +n sus
0n 5ort nu Ka #+ ma5at +m5+c+t n+c+oadata +ntr-o casa d+#er+ta.
Ce se +ntam5a cand NA' esueaa (
$aca nu e+sta n+c+ o cae de a ma5a +n mod un+c o cone+une ceruta de ut++ator; aceasta Ka #+ +=norata.
Aceas+ tratament Ka #+
a5+cat s+ 5ac,eteor care nu 5ot #+ cas+#+cate ca #acand 5arte d+ntr-o cone+une; d+n caua ca sunt
ma#ormate; sau mas+na nu
ma+ are memor+e etc.
Ma5ar+ mut+5e; su5ra5une+ s+ c+ocn+r+
Pot+ sa a+ re=u+ NA' care ma5eaa 5ac,etee 5e aceeas+ 5aaZ codu NA' este destu de +nte+=ent ca sa
eK+te c+ocn+r+e. Pot+ sa a+ doua
re=u+ care ma5eaa sursa adres+ 192.168.1.1 s+ 192.168.1.2 a 1.2.3. ... ceea ce este +n ord+ne.
Ma+ mut; 5ot+ sa ma5e+ 5este adrese reae; #oos+te; atata t+m5 cat s+ ee trec 5r+n mas+na care #ace
ma5area. $ec+; daca a+ o retea
as+=nata 1.2.3.!E2; dar a+ o retea +nterna care #ooseste acee adrese s+ una care #ooseste adrese 5r+Kate
192.168.1.!E2 5ot+ sa
#ac+ NA' #oarte s+m5u ma5and adresee sursa d+n 192.168.1.!E2 5este reteaua 1.2.3.!E2 #ara r+scu de a
se c+ocn+
U +5taes -t nat -A P/'R0'IN< -s 192.168.1.!E2 -o et,1 \
- /NA' --to 1.2.3.!E2
Aceeas+ o=+ca se a5+ca s+ adreseor #oos+te c,+ar de mas+na care #ace NA'; asa #unct+oneaa
masOuerad+n=u +m5arte aceeas+ adresa a
+nter#ete+ +nte 5ac,etee masOueradata s+ 5ac,etee BreaeB care K+n de a +nses+ mas+na res5ect+Ka.
C,+ar ma+ mut; 5ot+ ma5a aceeas+ 5ac,ete 5e ma+ mute t+nte; +ar ee Kor #+ +m5art+te. $e eem5u; daca nu
Kre+ sa ma5e+ n+m+c 5este
1.2.3.% a+ 5utea sa #ac+ asa
32
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
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nu ca +n cau ator ma5ar+ ae surse+. In mod natura amee ma5ar+ ae surse+ sunt +nKersate a 5ac,etee de
re5D care K+n.
". Protocoae s5ec+ae
0nee 5rotocoae nu e 5ace sa treaca 5r+n NA'. Pentru #+ecare d+ntre aceste 5rotocoae doua etens++
treu+e scr+seZ unu 5entru urmar+rea cone+un+or; +ar unu c,+ar 5entru NA'.
In +nter+oru d+str+ut+e+ net#+ter; e+sta modue 5entru #t5 +5conntrack#t5.o s+ +5nat#t5.o. $aca
+ntroduc+ aceste
2 modue +n kerne; atunc+ 5entru ut++area or+caru+ t+5 de NA' asu5ra 5rotocuu+ de #t5 Ka #unct+ona
corect. $aca nu
#oosest+ aceste modue; nu Ke+ 5utea sa #ac+ decat #t5 5as+K; sau c,+ar s-ar 5utea sa nu #unct+onee corect
daca #ac+
ma+ mut decat un s+m5u NA'.
8. $e#+c+ente ae NA'
$aca #ac+ NA' 5entru o cone+une; toate 5ac,etee care trec +n amee sensur+ +n s+ d+n +nter+oru retee+treu+e sa treaca 5r+n
mas+na care #ace NA'; at#e nu Ka #unct+ona cores5unator. In 5art+cuar; codu de urmar+re a cone+un+or
reasameaa 5ac,etee;
ceea ce +nseamna ca nu numa+ urmar+rea cone+un+or nu Ka #+ de +ncredere; dar 5ac,etee s-ar 5utea sa nu
treaca deoc; deoarece
#ra=mentee Kor #+ o5r+te.
9. /NA' s+ routarea
$aca #ac+ /NA'; Ke+ Krea sa te as+=ur+ ca #+ecare mas+na a care se duc 5ac,etee care trec 5r+n /NA' tr+m+t
re5DBur+ +na5o+ a mas+na care
#ace /NA'. $e eem5u; daca ma5e+ n+ste 5ac,ete a adresa sursa 1.2.3.; atunc+ routeru d+n a#ara treu+e
sa st+e sa tr+m+ta re5DBur+care Kor aKea dest+nat+a 1.2.3. +na5o+ a aceasta mas+na. ACest ucru se 5oate #ace +n #eu urmator
1. $aca #ac+ /NA' 5entru adresa 5ro5r+e a mas+n++ 5entru care routarea s+ toate ceeate
#unct+oneaa; nu treu+e sa #ac+ n+m+c.
2. $aca #ac+ NA' 5e o adresa ne#oos+ta d+n )AN de e. ma5e+ 5e 1.2.3.99; un IP +er 5e
1.2.3.!E2; mas+na care #ace NA' Ka
treu+ sa st+e sa ras5unda a cerer+ ARP 5entru acea adresa 5recum s+ 5entru a e+ +nses+. Ce ma+ usor ar
#+ crearea unu+ a+as a
+nter#ete+
U +5 address add 1.2.3.99 deK et,!
3. $aca #ac+ /NA' 5e o adresa com5et d+#er+ta; treu+e sa te as+=ur+ ca mas+n+e 5e care 5ac,etee/NA' e Kor oK+ Kor routa
5ac,etee +na5o+ a mas+na care #ace NA'. Acest ucru este dea #acut +n mas+na care #ace NA'; +n
=atewaDBu +m5+c+t; at#e Ka
treu+ sa #ac+ BadKert+eB 5entru o ruta daca #oosest+ un 5rotoco de routare sau sa adau=+ manua
route a #+ecare mas+na +m5+cata.
1!. $NA' 5e aceeas+ retea
3
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Network resource Host name IP-address MAC-address Resource comment
---------------- --------- --------------- ------------ ----------------------------
\\PAN PAN 192.168.123.18 !!!1!2!a"#1
\\A$INA A$INA 192.168.123.1"% !!!"9%cd!2de
\\A$IN&''& ( ( (
\\A)AH ( ( ( *+,ad
\\A)& A)& 192.168.123.33 !!!1!2!2"6
\\A//0R A//0R 192.168.123.16 !!c!268c%"1
\\A'H)NP A'H)NP 192.168.123.12! !!!6#!%298 Ae22
\\4&4I$& ( ( ( Andreea\\4I4A 4I4A 192.168.123.123 !!3!8!a"6%2 4+a
\\CACH CACH 192.168.123.11 !!%!22d39611
\\CRI/'I ( ( ( 'ata 5urade+or
\\CRI/'IAN ( ( ( Cr+st+an 29A sc.C
\\$A)& ( ( ( daecor+na7radu
\\$0M4RAA ( ( (
\\:)RIN :)RIN 192.168.123.32 !!e!"d!2edc6 :or+n; 4.29A; sc.C; a5.11
\\ 29A sc.A\\PI'?@ PI'?@ 192.168.123.29 !!a!d21c3e @R A)>@R 192.168.123.1! !!e!ca!1! Pc-uB uB A+n
\\IR&) IR&) 192.168.123."2 !!e!18212%c
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U +5taes -t nat -A PR&R0'IN< -d 1.2.3. \
-5 tc5 --d5ort 8! - $NA' --to 192.168.1.1
sout+e ar #+ sa rue+ un serKer $N/ +ntern care st+e adresa reaa +nterna a serKeruu+ de we 5u+c; s+ sa
#orwardee toate
ceeate cerer+ unu+ serKer $N/ etern. Asta +nseamna ca urnaee de 5e serKeru we Kor arata adrese IP
+nterne corect.
Ata sout+e ar #+ ca mas+na care #ace NA' sa ma5ee sursa adrese+ IP cu a e+ +nses+ 5entru aceste cone+un+;
5aca+nd serKeru sa
ras5unda 5r+n ea. In acest eem5u; Kom #ace urmatoru ucru st++nd ca adresa +nterna a mas+n++ care #ace
NA' este 192.168.1.2%!
U +5taes -t nat -A P/'R0'IN< -d 192.168.1.1 -s 192.168.1.!E2 \
-5 tc5 --d5ort 8! - /NA' --to 192.168.1.2%!
$eoarece re=ua +n antu PR&R0'IN< Ka #+ eecutata 5r+ma; 5ac,etee Kor #+ dea dest+nate 5entru
serKeru we +ntern 5utem sa ne dam
seama care sunt mod+#+cate +ntern a IP sursa.
11. Mutum+r+
Mutumesc +n 5r+mu rand a atc,