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I have a Linux network set up with three sub networks (chaos), (chaos-hs), and (ute-netz) with three machines casimir, ute, raspberry, a nas server nas and a router speedport:   casimir.chaos (serves as gateway for all local machines)  speedport.chaos (internet router)   casimir-hs.chaos-hs (dhcp server for chaos-hs and chaos)   ute.chaos-hs  nas.chaos-hs   ute.ute-netz (dhcp-server for ute-netz)  raspberry.ute-netz

The routing on casimir is set up as

Target          Router          Genmask         Flags Metric Ref    Use Iface         UG    0      0        0 eth1   U     0      0        0 eth1   U     0      0        0 eth0   UG    0      0        0 eth0

The routing on ute is set up as

Target          Router          Genmask         Flags Metric Ref    Use Iface         UG    0      0        0 eth0   U     0      0        0 eth0   U     0      0        0 eth1

There is no firewall setup on casimir or ute.

All normal connections work, e.g. I can ssh and ping from ute, casimir and raspberry into any of the other machines. I can also ping the nas from casimir and from ute.

But I cannot ping the nas from raspberry.

My assumption is the problem is caused by the fact that the nas which gets its IP from casimir via DHCP installs a default route with gateway but does not have an explicit routing for the ute-netz network. So, any requests from raspberry goto ute, then to the nas, but on their way back they go to casimir via chaos-hs and then would have to go back on the same interface chaos-hs to go to ute to eventually end up with raspberry.

I cannot log into the nas to control the routing. I can only supply configuration through DHCP.

Is there any way to further debug / fix this?

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