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. WIKIMERIONET
Merion Mertics , ,

CRM

DHCP Cisco

2. Dynamic Host Configuration Protocol

8

NAT/PAT Cisco.

DHCP.


1

, :

  • - , NAT inside.
  • - , NAT outside.
  • , - 192.168.12.2.
  • NAT ISP.
  • ISP 172.16.1.0 / 24, NAT.
  • BGP NAT ISP 192.168.34.0/24.
  • , - TCP- 80 192.168.34.3 .

, -. NAT:

show ip nat translations

, :

  • Inside local IP- .
  • Inside global IP- 172.16.1.0/24.
  • Outside local and global IP- -

, IP- .

show ip route | include 192.168.34.0

, NAT 192.168.34.0 / 24 BGP.

telnet

NAT- -, . . IP, NAT, :

 IP,    NAT,

IP- -, . IP- - 192.168.23.2, , , ISP , 192.168.23.0 / 24. , 192.168.23.0 / 24 ISP.

, - -, - NAT IP- 172.16.1.0/24. IP :

 IP

, IP- NAT ISP:

  1. ISP IP- , , 192.168.34.0 / 24.
  2. 192.168.34.0/24 ISP, ARP MAC- -, ARP IP- -.
  3. - , IP- IP- 172.16.1.
  4. - ISP , IP- ISP.
  5. ISP , , , 172.16.1.0 / 24.
  6. ISP , 172.16.1.0 / 24, IP-.

, ISP. , , !

ISP#debug ip packet 1
IP packet debugging is on for access list 1
ISP#conf t
ISP(config)#access-list 1 permit host 192.168.34.4

IP- , IP- -.

, -.

 ISP

, ISP. , , IP- 172.16.1.1 to...it .

? ISP- 172.16.1.0 /24 . BGP NAT:

NAT(config)#ip route 172.16.1.0 255.255.255.0 null 0
NAT(config)#router bgp 1
NAT(config-router)#network 172.16.1.0 mask 255.255.255.0

, 172.16.1.0 / 24 null0. , , . - BGP.

!

: , , translated .

2

. - DHCP-, - DHCP-. , , IP- ... ?

     DHCP      DHCP

, DHCP DHCP. .

     DHCP      DHCP

, DHCP / IP-. ...

debug dhcp detail

, , debug dhcp detail, , DHCP DHCP.

, . , DHCP- DHCP Discover. , , .

DHCPServer#show ip dhcp pool
show ip dhcp pool

show ip dhcp pool, , DHCP. , DHCP "MYPOOL", 192.168.12.0 / 24. .

show ip dhcp server statistics

show ip dhcp server statistics, , DHCP. , ... ?

show ip sockets

. show ip sockets , . , ... 67 (DHCP), , DHCP .

DHCPServer(config)#service dhcp

.

show ip sockets

- ! , 67, , DHCP .

  IP-  DHCP

DHCP , , IP- DHCP ... !

: , , DHCP .

3

   3

. 3 ; DHCP- FastEthernet0/0. DHCP-. , DHCP- , . ip helper , relay. , IP- DHCP

show ip interface brief

, DHCP. show ip interface brief.

DHCPClient(config)#interface fastEthernet 0/0
DHCPClient(config-if)#shutdown
DHCPClient(config-if)#no shutdown

up down , DHCP Discover.

show ip dhcp server statistics

, DHCP Discover DHCP-. , IP helper, . DHCP , DHCPACK (Acknowledgment). , - ...

DHCPServer#debug ip dhcp server packet

, , .

DHCP-   IP- 192.168.12.2

, DHCP- IP- 192.168.12.2, FastEthernet0/0 . DHCP-, IP-?

show ip route

, , , IP- 192.168.12.2 .

debug ip packet

,

IP-  192.168.12.2

, IP- 192.168.12.2 , IP- . .

DHCPServer(config)#ip route 192.168.12.0 255.255.255.0 192.168.23.2

, .

, IP- DHCP.

  IP-  DHCP

"debug ip dhcp server packet" , DHCP:

  1. DHCP Discover
  2. DHCP Offer
  3. DHCP Request
  4. DHCP ACK

... !

: IP helper, , DHCP- , , .

3 FHRP Cisco .