Difference between revisions of "Cisco NAT"
Helikopter (talk | contribs) |
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Testa om NAT funkar | Testa om NAT funkar | ||
debug ip nat | debug ip nat | ||
| + | |||
telnet 1.1.1.1 /source lo0 | telnet 1.1.1.1 /source lo0 | ||
who | who | ||
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access-list 10 permit [ip-address] [wildcard-mask] | access-list 10 permit [ip-address] [wildcard-mask] | ||
ip nat inside source list 10 interface [outside-interface] overload | ip nat inside source list 10 interface [outside-interface] overload | ||
| + | Man kan även skapa en pool med endast en ip adress och köra overload på den. | ||
| + | |||
Verify | Verify | ||
show ip nat translations | show ip nat translations | ||
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==Static NAT== | ==Static NAT== | ||
interface Gi0/1 | interface Gi0/1 | ||
| − | ip address | + | ip address 100.10.10.10 255.255.255.0 |
ip nat outside | ip nat outside | ||
interface Gi0/2 | interface Gi0/2 | ||
| Line 29: | Line 32: | ||
ip nat inside | ip nat inside | ||
NAT | NAT | ||
| − | ip nat inside source static 192.168.0.20 | + | ip nat inside source static 192.168.0.20 100.10.10.20 [no-alias] |
''Med no-alias besvaras inte ARP-förfrågningar för den IP-adressen.'' | ''Med no-alias besvaras inte ARP-förfrågningar för den IP-adressen.'' | ||
| Line 40: | Line 43: | ||
===Static PAT=== | ===Static PAT=== | ||
interface Gi0/1 | interface Gi0/1 | ||
| − | ip address | + | ip address 100.10.10.10 255.255.255.0 |
ip nat outside | ip nat outside | ||
interface Gi0/2 | interface Gi0/2 | ||
ip address 192.168.0.1 255.255.255.0 | ip address 192.168.0.1 255.255.255.0 | ||
ip nat inside | ip nat inside | ||
| − | PAT / port forward | + | PAT / port forward. |
| − | ip nat inside source static tcp 192.168.0.55 80 | + | ip nat inside source static tcp 192.168.0.55 80 100.10.10.10 80 |
Verify | Verify | ||
show ip nat translations | show ip nat translations | ||
| + | show ip aliases | ||
===Static Extendable NAT=== | ===Static Extendable NAT=== | ||
| Line 57: | Line 61: | ||
==Dynamic NAT== | ==Dynamic NAT== | ||
interface Gi0/1 | interface Gi0/1 | ||
| − | ip address | + | ip address 100.10.10.10 255.255.255.0 |
ip nat outside | ip nat outside | ||
interface Gi0/2 | interface Gi0/2 | ||
| Line 65: | Line 69: | ||
ip access-list standard CLIENT-LIST | ip access-list standard CLIENT-LIST | ||
permit 192.168.0.0 0.0.0.15 | permit 192.168.0.0 0.0.0.15 | ||
| − | ip nat pool DYNAMIC | + | |
| + | ip nat pool DYNAMIC 100.10.10.15 100.10.10.19 prefix-length 29 | ||
ip nat inside source list CLIENT-LIST pool DYNAMIC | ip nat inside source list CLIENT-LIST pool DYNAMIC | ||
| + | |||
Verify | Verify | ||
show ip nat translations | show ip nat translations | ||
| Line 72: | Line 78: | ||
==Static Policy NAT== | ==Static Policy NAT== | ||
| − | Policy NAT använder route-maps. | + | Policy NAT använder route-maps. Med match interface kan man bestämma vilket interface paketen ska skickas ut på och därmed natas. |
ip access-list extended TO_OUTSIDE | ip access-list extended TO_OUTSIDE | ||
permit ip 192.168.0.0 0.0.0.255 any | permit ip 192.168.0.0 0.0.0.255 any | ||
| + | |||
route-map TO_ISP1 permit 10 | route-map TO_ISP1 permit 10 | ||
match ip address TO_OUTSIDE | match ip address TO_OUTSIDE | ||
match interface Gi0/0 | match interface Gi0/0 | ||
| + | |||
ip nat inside source route-map TO_ISP1 interface Gi0/0 overload | ip nat inside source route-map TO_ISP1 interface Gi0/0 overload | ||
| + | |||
| + | ==Reversible NAT== | ||
| + | Man kan konfigurera nat som endast funkar efter att ha blivit initierad från andra hållet. | ||
| + | ip nat pool POOL 100.10.10.15 100.10.10.19 netmask 255.255.255.0 | ||
| + | ip nat inside source route-map ROUTE-MAP pool POOL reversible | ||
==Overlapping Subnets== | ==Overlapping Subnets== | ||
| Line 84: | Line 97: | ||
===Dubbel-NAT=== | ===Dubbel-NAT=== | ||
| − | 172.20.0.10 kommunicerar mot 172.20.0.50 som natas till 30.0.0.5 | + | 172.20.0.10 kommunicerar mot 172.20.0.50 som natas till 30.0.0.5 medans 30.0.0.5 ser trafik från 30.0.0.50. |
ip nat inside source static 172.20.0.10 30.0.0.50 | ip nat inside source static 172.20.0.10 30.0.0.50 | ||
ip nat outside source static 30.0.0.5 172.20.0.50 add-route | ip nat outside source static 30.0.0.5 172.20.0.50 add-route | ||
| Line 95: | Line 108: | ||
address 10.0.0.10 10.0.0.10 | address 10.0.0.10 10.0.0.10 | ||
address 10.0.0.11 10.0.0.11 | address 10.0.0.11 10.0.0.11 | ||
| + | address 10.0.0.12 10.0.0.12 | ||
| + | |||
ip nat inside destination list DISTRIBUTE_LOAD pool ROTARY | ip nat inside destination list DISTRIBUTE_LOAD pool ROTARY | ||
| Line 120: | Line 135: | ||
interface Gi0/2 | interface Gi0/2 | ||
ip nat enable | ip nat enable | ||
| + | |||
| + | ip nat source static 192.168.0.1 100.10.10.10 | ||
Show | Show | ||
show ip nat nvi translations | show ip nat nvi translations | ||
| − | |||
| − | |||
| − | |||
==IPv6== | ==IPv6== | ||
Revision as of 20:13, 2 November 2016
Network Address Translation används för att skriva om adresser i IP-paket. Det är inte säkert att NAT fungerar tillsammans med ACL:er som använder log så det bör man ha i åtanke. För att accelerera NAT-processen finns ip nat create flow-entries som är påslaget default i IOS-routrar.
Testa om NAT funkar
debug ip nat telnet 1.1.1.1 /source lo0 who
Contents
Overload
access-list 10 permit [ip-address] [wildcard-mask] ip nat inside source list 10 interface [outside-interface] overload
Man kan även skapa en pool med endast en ip adress och köra overload på den.
Verify
show ip nat translations show ip nat statistics
Default Interface
NAT Default interface innebär att all trafik som initieras utifrån och natas in går till en och samma IP men däremot kan trafik som initieras inifrån natas till interface IP (nat overload).
ip access-list standard ALL permit any ip nat inside source list ALL interface Gi2 overload ip nat inside source static 172.16.0.20 interface Gi2
Static NAT
interface Gi0/1 ip address 100.10.10.10 255.255.255.0 ip nat outside interface Gi0/2 ip address 192.168.0.1 255.255.255.0 ip nat inside
NAT
ip nat inside source static 192.168.0.20 100.10.10.20 [no-alias]
Med no-alias besvaras inte ARP-förfrågningar för den IP-adressen.
Verify
show ip nat translations show ip nat statistics show ip alias
DYNAMIC är IP-adresser som används för NAT.
Static PAT
interface Gi0/1 ip address 100.10.10.10 255.255.255.0 ip nat outside interface Gi0/2 ip address 192.168.0.1 255.255.255.0 ip nat inside
PAT / port forward.
ip nat inside source static tcp 192.168.0.55 80 100.10.10.10 80
Verify
show ip nat translations show ip aliases
Static Extendable NAT
Om man vill ha flera ip-adresser som ska natas till samma IP.
ip nat inside source static 10.1.1.1 20.0.0.20 extendable ip nat inside source static 10.1.1.1 20.0.0.30 extendable
Dynamic NAT
interface Gi0/1 ip address 100.10.10.10 255.255.255.0 ip nat outside interface Gi0/2 ip address 192.168.0.1 255.255.255.0 ip nat inside
NAT
ip access-list standard CLIENT-LIST permit 192.168.0.0 0.0.0.15 ip nat pool DYNAMIC 100.10.10.15 100.10.10.19 prefix-length 29 ip nat inside source list CLIENT-LIST pool DYNAMIC
Verify
show ip nat translations show ip nat pool name DYNAMIC
Static Policy NAT
Policy NAT använder route-maps. Med match interface kan man bestämma vilket interface paketen ska skickas ut på och därmed natas.
ip access-list extended TO_OUTSIDE permit ip 192.168.0.0 0.0.0.255 any route-map TO_ISP1 permit 10 match ip address TO_OUTSIDE match interface Gi0/0 ip nat inside source route-map TO_ISP1 interface Gi0/0 overload
Reversible NAT
Man kan konfigurera nat som endast funkar efter att ha blivit initierad från andra hållet.
ip nat pool POOL 100.10.10.15 100.10.10.19 netmask 255.255.255.0 ip nat inside source route-map ROUTE-MAP pool POOL reversible
Overlapping Subnets
Antingen får man NATa på båda sidorna eller bara ena.
Dubbel-NAT
172.20.0.10 kommunicerar mot 172.20.0.50 som natas till 30.0.0.5 medans 30.0.0.5 ser trafik från 30.0.0.50.
ip nat inside source static 172.20.0.10 30.0.0.50 ip nat outside source static 30.0.0.5 172.20.0.50 add-route
Utan add-route måste en statisk route användas för att peka 172.20.0.50 till outside interface.
show ip nat translations
TCP Load Distribution
Rotary address pool
ip nat pool ROTARY prefix-length 24 type rotary address 10.0.0.10 10.0.0.10 address 10.0.0.11 10.0.0.11 address 10.0.0.12 10.0.0.12 ip nat inside destination list DISTRIBUTE_LOAD pool ROTARY
HSRP
Stateful NAT with HSRP. During failovers, NAT translated IP addresses on devices may be different from the IP address before the failover, because no state information is exchanged between active and standby devices. HSRP Virtual IP Address (VIP) cannot be used by NAT pools.
interface gi2 standby 100 name SNAT ip nat stateful id 1 redundancy SNAT mapping-id 10 ip nat pool SNATPOOL 10.1.1.1 10.1.1.9 prefix-length 24 ip nat inside source route-map ROUTE-MAP pool SNATPOOL mapping-id 10 overload
Primary
ip nat stateful id 1 primary 10.10.10.10 peer 10.22.22.22 mapping-id 10
Backup
ip nat stateful id 1 backup 10.2.2.2 peer 10.10.10.10 mapping-id 10
Verify
show ip snat distributed verbose
NVI
Med Nat Virtual Interface kan man adressöversätta mellan VRF:er och man använder inte inside och outside med denna metod.
interface Gi0/1 ip nat enable interface Gi0/2 ip nat enable ip nat source static 192.168.0.1 100.10.10.10
Show
show ip nat nvi translations
IPv6
NAT – Protocol Translation kan användas vid IPv4 till IPv6 migreringar och ger bi-directional connectivity mellan domänerna.
interface gi 0/0 ipv6 nat interface gi 0/1 ipv6 nat ipv6 nat v6v4 source 3001:11:0:1::1 150.11.3.1 ipv6 nat v4v6 source static 150.11.2.2 2000::960b:0202 ipv6 nat prefix 2000::/96
NAT-PT kräver ett /96 prefix
Verify
show ipv6 nat translations
