IP alias/redirect - please help - Cabling-Design.com Forums

Hi,

I've searched the newsgroups for a while, but haven't found a solution for my problem.

Here is the situation:

We have two sites (site1 and site2 in two different countries) and a hosted/colocated server at an ISP.

For some reason, scince last week we have a packet loss of about 10 -

20 % between site1 and the hosted server. However, site1site2 and site2server work without problems. Scince it will take a while until the ISPs find out what the problem is and they don't want to change the routing (on their backbones ;-) ), I need a solution, how to connect site1 with the hosted server again.

I thought about NAT as the simpliest solution.

Both sites are equipped with Cisco 2600 routers. The configuration on both routers is similar:

Site1: Cisco 2651

2 x FastEthernet one FastEthernet is connected to the ISP's router, the other is connected to the LAN

Site2: Cisco 2621

2 x FastEthernet one FastEthernet is connected to the ISP's router, the other is connected to the LAN

On site2 there are some unused public IP addresses.

The idea is to assign an unused IP at site2 to the hosted server, and another unused IP adress also at site2 to site1.

A packet that arrives from site1 at site 2 (at the public IP) would have to be routed through NAT to the hosted server. The other way it would be similar.

If I understand right, the packets would have to be routed "inside" the outside interface.

Is that possible ? Or is there any other solution for my problem ?

Thanks in advence.

Best regards

Alexej Buchholz

In article , wrote: :On site2 there are some unused public IP addresses.

:The idea is to assign an unused IP at site2 to the hosted server, and :another unused IP adress also at site2 to site1.

:A packet that arrives from site1 at site 2 (at the public IP) would :have to be routed through NAT to the hosted server. The other way it :would be similar.

:If I understand right, the packets would have to be routed "inside" the :outside interface.

:Is that possible ?

Yes, what you propose should work.

Alternate methods:

- create a GRE tunnel between the two sites. On site1, route the hosted server via the tunnel. On site2, the tunnel is the "nat inside". You should be able to do GRE with any feature set, I -think-.

- create an IPSec VPN between the two sites, and otherwise proceed as for the GRE tunnel. You would need the IPSec feature (or whatever

Security that got incorporated into in 12.3 / 12.4).

We have a situation of 100% packet loss between some of our offices and our HQ (also known as "ISPs filtering packets they consider unsafe"); we handle it by relaying via our local office in IPSec tunnels and having our local office do the NAT. [We do not happen to be handling it via routers, though: we happen to be handling it via PIX.]