Solaris

many thanks for the fast replaies, my last question
can I configure 2 different DGW to each interface

I think it is possible for example if each interface is in its own zone.

(Get the PDF : SystemAdministration Guide: Solaris Containers-Resource Management and Solaris Zones)

And read in Chapter/subsection :
-> Solaris Zone Administration
-> Using IP Network Multipathing on a Solaris system With Zones Installed
-> Solaris 10 8/07: How to Use IP Network Multipathing in Exclusive-IP Non-Global Zones
-> How to Extend IP Network Multipathing Functionality to Shared-IP Non-Global Zones

No, generally not.

TCP/IP routing is above the link layer. That means that you can generally have only one default gateway per host.

Default mean "if there are no routes in the routing table, send the packet here" which means that there should only be one default gateway.

i had same problem. and had to leave just one default gw. iirc, it was possible to define two of them, but then some packets would get lost (presumably sent to wrong one).

If you need more granularity on routing, based on interface, you should either add more static routes or run a dynamic routing protocol on your network.

For special cases where you might want to direct a subset of traffic to a particular interface, it is easier to do this by configuring static routes. A "default route" means "if there is no entry in the routing table, send the packet here". There should not be two "defaults". There should be only one. If you need more specific routing, add more static routes to your routing table.