Some IP range can't ping router public IP, need to add static route.

[lamkuokcheng]

Dear all,

i setup two default route for two subnet NAT to internet at a 2801 router, but i found some time it will occur the problem, outside host can not ping the public IP at fa0/1 ADSL interface, problem detail as following:

two outside interface

interface fa0/1-- IP: 202.XXX.XXX.XX  --> IP-A

interface serial 0/3/0 - IP: 202.xxx.xxx.xxx  IP-B

two default gateway

ip route 0.0.0.0 0.0.0.0 202.XXX.XXX.XXX

ip route 0.0.0.0 0.0.0.0 serial 0/3/0

i using route-map at inside interface for the different subnet goes to different default route to the internet

Problem:

Problem is some public IP range, can not ping the public IP- A (202.XXX.XXX.XXX) at interface fa0/1.

when i add a static route for the outside IP (which can not ping our IP-A), after i add the route, the ping become success.

how can i fix this problem?

please help!

best regards

[Sebastian Helmer]

Hi, Did they maybe match your route-map config?

Or is maybe here the problem

     two default gateway

     ip route 0.0.0.0 0.0.0.0 202.XXX.XXX.XXX

     ip route 0.0.0.0 0.0.0.0 serial 0/3/0

Is it not possible to define it more detailed..Two default gateway's are from my point of view always bad. Is the route-map config not enough with one DG.

-Sebastian

[connectone]

Can you provide some more information like what the routemap looks like.  By default, the router will use the

Static route you have the serial interface defined as it has an admin distance of 0 over

the admin distance of 1 for the IP next hop.

When you say outside host, do you mean people in the internet trying to reach your network IP's of your users behind the 2801 trying to reach some IP address out on the internet.

I am going to assume you have two ISP's attached to this router and they are providing the IP's to you and they are statically routing towards your router.  Meaning they are announcing the IP space you are putting on the router to the rest of the internet or are you advertising the IP space to two external ISP's.  Trying to understadn the layout of your network to help with your issue.

If you could provide more information, drawing, config etc it would help make troubleshooting this a little easier.

Thanks

Frank