05-28-2013 06:57 PM - edited 03-04-2019 08:02 PM
Hi.
I've got an 887M router which will be configured with two linke - one ADSL, one 3G - both of which will have (obviously) a separately suppplied IP address from the different ISP's being used. The 3G is a backup - plain and simple - for use only when the DSL service flakes out (which it does often)
Routing is pretty simple - I'll either do soemthing with a bit of PBR, or a simple weighted static, but the NAT has me scratching my head a little.
Can I have two outbound NAT pools (ip nat outside) for each interface which will be used ONLY for traffic going out the interface concerned?
For example, I have one for the primary link
ip nat inside source list 2 interface Dialer1 overload
Can I do the same for the second dialer interface like this
ip nat inside source list 2 interface Dialer2 overload
and have them automatically switch to using the dialer 2 IP for the outbound NAT if the dialer 1 link fails?
I don't think I've ever come across this before, so I'm not sure if it can even be done.
Thanks for any input.
Solved! Go to Solution.
05-28-2013 08:24 PM
darren:
Just go:
interface Dialer 1
Description Primary link ISP1
ip address 78.x.x.x 255.255.255.0
ip nat outside
interface Dialer 2
Description Secondary link ISP2 (3G)
ip address 79.x.x.x. 255.255.255.0
ip nat outside
interface FastEthernet1/1
Description Inside LAN segment
ip address 172.168.60.1 255.255.255.0
ip nat inside
access-list 100 permit ip 172.168.60.0 0.0.0.255 any
access-list 100 permit ip 172.168.60.0 0.0.0.255 any
route-map isp1 permit 10
match ip address 100
match interface Dialer 1
route-map isp2 permit 10
match ip address 100
match interface Dialer 2
ip nat inside source route-map isp1 interface Dialer 1 overload
ip nat inside source route-map isp2 interface Dialer 2 overload
ip route 0.0.0.0 0.0.0.0 79.y.y.y -----> Primary Default route pointing towards Next hop ip of ISP1
ip route 0.0.0.0 0.0.0.0 78.y.y.y 10 -----> Backup Default route with higher AD (10) pointing towards Next hop ip of ISP2 (3G)
let me know if it works
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05-28-2013 08:24 PM
darren:
Just go:
interface Dialer 1
Description Primary link ISP1
ip address 78.x.x.x 255.255.255.0
ip nat outside
interface Dialer 2
Description Secondary link ISP2 (3G)
ip address 79.x.x.x. 255.255.255.0
ip nat outside
interface FastEthernet1/1
Description Inside LAN segment
ip address 172.168.60.1 255.255.255.0
ip nat inside
access-list 100 permit ip 172.168.60.0 0.0.0.255 any
access-list 100 permit ip 172.168.60.0 0.0.0.255 any
route-map isp1 permit 10
match ip address 100
match interface Dialer 1
route-map isp2 permit 10
match ip address 100
match interface Dialer 2
ip nat inside source route-map isp1 interface Dialer 1 overload
ip nat inside source route-map isp2 interface Dialer 2 overload
ip route 0.0.0.0 0.0.0.0 79.y.y.y -----> Primary Default route pointing towards Next hop ip of ISP1
ip route 0.0.0.0 0.0.0.0 78.y.y.y 10 -----> Backup Default route with higher AD (10) pointing towards Next hop ip of ISP2 (3G)
let me know if it works
=============================
Please remember to rate useful posts, by clicking on the stars below.
=============================
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