688 IT Telegram . ?

(Extended ACL)

Cisco

3

Cisco, () . . :

  • IP- - IP- ;
  • - / ;
  • TCP/IP - TCP, UDP, IP ;

?

. :

access list NUMBER permit|deny IP_PROTOCOL SOURCE_ADDRESS WILDCARD_MASK [PROTOCOL_INFORMATION] DESTINATION_ADDRESS WILDCARD_MASK PROTOCOL_INFORMATION

:

  • NUMBER - ;
  • PERMIT/DENY - ;
  • SOURCE/DESTINATION ADDRESS - ;
  • WILDCARD_MASK - ;
  • PROTOCOL_INFORMATION - TCP, UDP, IP ;

, wildcard () , :

( ):

 ip access-group NUMBER out
in out ,
: 100 199 2000 2699

( 1)

, 10.0.0.0/24 S2 ( 192.168.0.1), S1 ( 172.16.0.1/24).

, ACL S2. :

access-list 100 permit ip 10.0.0.0 0.0.0.255 192.168.0.1 0.0.0.0

10.0.0.0 192.168.1.0. , S1:

 access-list 100 deny ip 10.0.0.0 0.0.0.255 172.16.0.1 0.0.0.0

, R1:

int fa0/0
ip access-group 100 in
( 2)

: 10.0.0.0/24 S1, 80. - , - , Telnet.

2

, - 80, 

access-list 100 permit tcp 10.0.0.0 0.0.0.255 172.16.0.1 0.0.0.0 eq 80

TCP, . , 10.0.0.0 172.16.0.1 80 (-).

Telnet 10.0.0.0 172.16.0.1. -, :

access-list 100 deny tcp 10.0.0.0 0.0.0.255 172.16.0.1 0.0.0.0 eq 23

, :

int fa0/0
ip access-group 100 in
, . , .

?

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