NAT Cisco
360: NAT
NAT (Network Address Translation) Cisco.
NAT (Static NAT)
, NAT . .
, - , .
, - IPv4. NAT, -. - IPv4-. NAT IPv4- .
NAT :
- (inside local) (inside global) . , 192.168.1.5 208.165.100.5 NAT .
- , , (inside) (outside) NAT. Serial 0/0/0 , Serial 0/1/0 .
, Serial 0/0/0 IPv4 (192.168.1.5), . , Serial 0/1/0, IPv4 (208.165.100.5), (192.168.1.5) .
:
- . ip nat inside source static [ _IP _IP]. no ip nat inside source static. , , ip nat inside source static [ _IP _ _].
- . , interface[ ] ip nat inside
- , ip nat outside
:
Router(config)# ip nat inside source static 192.168.1.5 208.165.100.5 Router(config)# interface serial0/0/0 Router(config-if)#ip nat inside Router(config-if)#exit Router(config)# interface serial0/1/0 Router(config-if)#ip nat outside
:
- -. -, IPv4- 208.165.100.5. -.
- , NAT, NAT. IPv4 NAT .
- 208.165.100.5 192.168.1.5 -.
- - , 192.168.1.5.
- - NAT -, 192.168.1.5. NAT , 192.168.1.5 208.165.100.5 Serial 0/1/0
- , . .
NAT
NAT show ip nat translations. NAT. , , NAT.
Router#show ip nat translations Pro Inside global Inside local Outside local Outside global --- 208.165.100.5 192.168.1.5 208.165.100.70 208.165.100.70
show ip nat statistics. , NAT, , .
Router#show ip nat statistics Total active translations: 1 (1 static, 0 dynamic; 0 extended) Peak translations: 2, occurred 00:00:21 ago Outside interfaces: Serial0/1/0 Inside interfaces: Serial0/0/0 Hits:7 Misses:0
, NAT , , clear ip nat statistics .
NAT (Dynamic NAT)
NAT , NAT ( IP-). NAT IPv4 . NAT, NAT, , NAT.
. 192.168.1.0/24 192.168.2.0/24 , NAT 208.165.100.5 - 208.165.100.15.
(inside global address pool) . NAT . , . , , .
:
- , ip nat pool [ _ip _ip]. . IP- IP- . netmask prefix-length .
- access-list (ACL), , . access-list [_ACL] permit source [wildcard_]. access-list ( ). ACL , deny all.
- ACL , ip nat inside source list [_ACL] number pool [_]. , () ().
- , , NAT, , .
- , , NAT, , .
:
Router(config)# ip nat pool MerionNetworksPool 208.165.100.5 208.165.100.15 netmask 255.255.255.0 Router(config)# access-list 1 permit 192.168.0.0 0.0.255.255 Router(config)#ip nat inside source list 1 pool MerionNetworksPool Router(config)# interface serial0/0/0 Router(config-if)#ip nat inside Router(config-if)#exit Router(config)# interface serial0/1/0 Router(config-if)#ip nat outside
:
- 192.168.1.10 192.168.2.10 208.165.100.70
- 192.168.1.10. , NAT, NAT, , . ACL , NAT. IP- , , 192.168.1.10 . R2 , 208.165.200.5. IPv4- (192.168.1.10) , (208.165.200.5) NAT. 192.168.2.10 , , - 208.165.200.6.
- .
- , 208.165.200.5. , 208.165.200.6.
- 208.165.200.5, NAT 192.168.1.10 . , .
- , . .
NAT
show ip nat , , , . verbose , , . 24 , ip nat translation timeout [__] .
, clear ip nat translation. NAT. , , . , . . .
show ip nat statistics , NAT, .
ACL, show access-lists.
Port Address Translation (PAT)
PAT ( NAT overload) , . , IPv4- IPv4-. , TCP UDP .
, , 65 536 IP-. , IP-, 4000.
PAT, , IPv4-. - IPv4- , IPv4-, -.
PAT IP-
IPv4-, , PAT. NAT, , . .
NAT, , overload, PAT.
PAT :
- , PAT , ip nat pool [ _ip _ip] netmask [] | prefix-length [_].
- access-list, , . access-list [_ACL] permit source [wildcard_].
- PAT, Overload. ip nat inside source list [_ACL] number pool [_] overload.
- , , NAT, . ip nat inside ip nat outside
, , PAT:
Router(config)# ip nat pool MerionNetworksPool2 208.165.100.5 208.165.100.15 netmask 255.255.255.0 Router(config)# access-list 1 permit 192.168.0.0 0.0.255.255 Router(config)#ip nat inside source list 1 pool MerionNetworksPool2 overload Router(config)# interface serial0/0/0 Router(config-if)#ip nat inside Router(config-if)#exit Router(config)# interface serial0/1/0 Router(config-if)#ip nat outside
PAT IPv4-
PAT IP . 192.168.0.0/16 ( ACL), , IPv4 208.165.99.225 ( IPv4 S0 /1/0). NAT.
:
- access-list , access-list [_ACL] permit source [wildcard_].
- , ip nat inside source list [_ACL] interface [ ] overload
- ip nat inside ip nat outside.
NAT, , IP . NAT .
:Router(config)# access-list 1 permit 192.168.0.0 0.0.255.255 Router(config)# ip nat source list 1 interface serial0/1/0 overload Router(config)# interface serial0/0/0 Router(config-if)#ip nat inside Router(config-if)#exit Router(config)# interface serial0/1/0 Router(config-if)#ip nat outside
PAT , .
PAT :
- -. 192.168.1.10 TCP 1444, 192.168.2.10 TCP 1444
- , PAT, IPv4- 208.165.99.225 (inside global address). NAT 1444, PAT 208.165.101.20.
- , PAT IPv4- - 208.165.99.225. , PAT 208.165.99.225. , PAT , PAT , . NAT 1445 . 208.165.99.225 1444, (1445) NAT . .
- , . , 208.165.99.225, , .
- , NAT . 208.165.99.255 , 1444. , IPv4 192.168.1.10, .
- , . IPv4 208.165.99.225 , 1445, . IPv4 192.168.2.10 1444, NAT.
Port Address Translation (PAT)
PAT , NAT. show ip nat translations IP show ip nat statistics , NAT, .
Router#show ip nat statistics Total active translations: 2 (0 static, 2 dynamic; 2 extended) Peak translations: 2, occurred 00:00:07 ago Outside interfaces: Serial0/1/0 Inside interfaces: Serial0/0/0 Hits:4 Misses:0 CEF Translated packets: 4, CEF Punted packets:0 Expired translations: 0 Dynamic mappings: -- Inside Source [Id: 3] access-list 1 pool MerionNetworksPool2 refcount 2 pool MerionNetworksPool2: netmask 255.255.255.0 start 208.165.100.5 end 208.165.100.15 type generic, total addressers 10, allocated 1(10%), misses 0 Total doors: 0 Appl doors: 0 Normal doors: 0 Queued Packets: 0
, debug ip nat, , . debug ip nat detailed, . , , . .
Router#debug ip nat IP NAT debugging is on Router# *Aug 24 16:20:331:670: NAT*: s=192.168.1.10->208.165.99.225 d=208.165.101.20 [3730] *Aug 24 16:20:331:682: NAT*: s=208.165.101.20 d=208.165.99.225 ->192.168.1.10 [4156] *Aug 24 16:20:331:698: NAT*: s=192.168.1.10->208.165.99.225 d=208.165.101.20 [3731] *Aug 24 16:20:331:702: NAT*: s=192.168.1.10->208.165.99.225 d=208.165.101.20 [3732] *Aug 24 16:20:331:710: NAT*: s=208.165.101.20 d=208.165.99.225 ->192.168.1.10 [4157]
:
- * () NAT , (fast-switched path). , .
- s= - IP
- a.b.c.d ? w.x.y.z - , a.b.c.d w.x.y.z.
- d= - IP
- [xxxx] - - IP.