Question about HSRP, NAT and route-map?

[jones.brandao]

Dear Firends,

I need help with HSRP with NAT. I have problem in some situations.

See attached image for example.

Situations:

1° If interface Gi0/0 is down, then the HSRP changes to router 2, but Gi 0/1 continues in router 1. When the packet leaves network B for network A, the packet dies in router A, because there is no have connection to network A.

2° If the packet leaves network A for network B, when the packet returns to the source, the packet dies in router 1, because there is no connection to network A.

[Kyle McKay]

You would typically want to implement some form of HSRP tracking mechanism to mitigate this problem.

HSRP tracking allows you to lower the HSRP priority of one router based on certain criteria. In this case, you could say that if Router 1 interface Gig0/1 goes down, lower the HSRP priority to a value lower than the priority of Router 2 (you need preemption for this to work correctly).

With this technology, if Router 1 interface Gig0/1 goes down, traffic is NOT routed from Network A to router #1, it would instead be sent to Router 2.

You would of course implement this for both HSRP instances to protect from this happening in either direction.

Please see this link for the configuration details:

http://www.cisco.com/en/US/tech/tk648/tk362/technologies_tech_note09186a0080094e8c.shtml

[paul driver]

Hello,

Please note I have not managed to testbed this.

RTRX

int gig0/1

Description Facing Network B

ip address 10.0.0.1 255.255.255.0

ip nat outside

standby 10 ip 10.0.0.3

standby 10 priority 115

standby 10 preempt

standby 10 name HRSP2

standby 10 track gig0/0 50

int gig0/0

Description Facing Network A

ip address 192.168.0.1 255.255.255.0

ip nat inside

standby 20 ip 192.168.0.3

standby 20 priority 115

standby 20 preempt

standby 20 name HRSP1

standby 20 track gig0/1 50

ip nat inside source static xxxx yyyy redundancy HRSP2

RTRX

int gig0/1

Description Facing Network B

ip address 10.0.0.2 255.255.255.0

ip nat outside

standby 10 ip 10.0.0.3

standby 10 priority 120

standby 10 preempt

standby 10 name HRSP2

standby 10 track gig0/0 50

int gig0/0

Description Facing Network A

ip address 192.168.0.2 255.255.255.0

ip nat inside

standby 20 ip 192.168.0.3

standby 20 priority 120

standby 20 preempt

standby 20 name HRSP1

standby 20 track gig0/1 50

ip nat inside source static xxxx yyyy redundancy HRSP2

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.