Hi all,

Imagine a domain D1 and a domain D2 are connected to a domain DA. But these two domains are also connected to a domain DB.

When message is routed from D1 to D2, it goes: D1 -> DA -> D2.
With link configuration tool, we can see that there is an indirect link between D1 and D2.
When DA is down, or when MTA on DA is not responding anymore:
- does the message automatically goes from D1 to D2 using DB ?
- do we have to perform any manual operation with the link configuration tool or other way, in order to achieve that feature ?
- To perform fault-tolerance, are we obliged to have direct link from D1 to D2 so when this direct link is down, messages go automatically through DA because it is kept as an indirect link between D1 and D2 ?

Load balancing
For load balancing, we can play with routing domain at the domain level in order for D1 to route evenything through DA and for D2 to route everything through DB.
In such situation it is not possible to do fault-tolerance anymore, correct ?