Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

Weird Question

If the configuration between two sites is like below, how can i tell the routes to the routers?

Please don't mind if it is silly or i'm missing some basics.

weird question.PNG

Regards,

Chandu

Regards, Chandu
Everyone's tags (1)
2 ACCEPTED SOLUTIONS

Accepted Solutions

Weird Question

Hi,

NAT for overlapping subnets might be a solution for you?

See

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f30.shtml

for details.

Best regards,

Milan

Weird Question

There are no such thing as silly questions

You seem to have the same subnet (10.0.1.0 /24) on both sides which will not work as they are separated by a router...or two routers in this case.

When a Router recieves a packet, it does a lookup in its routing table for the destination IP address.

In your example, how would the Router know where to forward the packet if the 10.0.1.0 /24 subnet exists on both sides?

4 REPLIES

Weird Question

Hi,

NAT for overlapping subnets might be a solution for you?

See

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a0080093f30.shtml

for details.

Best regards,

Milan

Weird Question

There are no such thing as silly questions

You seem to have the same subnet (10.0.1.0 /24) on both sides which will not work as they are separated by a router...or two routers in this case.

When a Router recieves a packet, it does a lookup in its routing table for the destination IP address.

In your example, how would the Router know where to forward the packet if the 10.0.1.0 /24 subnet exists on both sides?

New Member

Weird Question

Got it.

So with the help of natting this is possible.

Regards,

Chandu

Regards, Chandu

Weird Question

Yes,

that's possible.

But I'd use this solution as a last chance only in a case it's absolutely impossible to readdress one of those subnets.

IMHO, it's much easier to change an address of one /24 subnet than to run two subnets with overlapping addresses for a long time.

Users will totally be confused by the same addresses on both sites and any troubleshooting would be a nightmare.

Best regards,

Milan

129
Views
9
Helpful
4
Replies