Mihamina RKTMB wrote: > Hi all, > > I rent a dedicated server where I installed an hypervisor and purchased > failover public IPv4 IPs routed to that server. > > When configuring the Debian VMs to use those failover IPs, I have to > > - set the address to /32: "ip addr add $IP/32 dev eth0" > > - set the traffic to the gateway to go through the NIC: "ip route add $GW > dev eth0" > > - set the default route to go via the gateway: "ip route add default via > $GW" > > As I set the IP address to a /32, the gateway is not (never) in the subnet > of the VM. > > When using the Debian installer, at the networking setup, the installer > refuses that setting: the gateway is not in the subnet of the set IP > address. > > The workaround I use is either to > > - finish the installation without network and then at reboot, setup the > network > > - manually setup the network during installation in another console > > But isn't there a way to make the Debian installer accept that the gateway > is not in the subnet of the set IP address?
No. I presume that your server rental includes an address on an IPv4 or IPv6 network via DHCP or as a static assignment. That is how the server reaches everything else, the default. You can add more IPs to that interface. If your upstream network sends traffic there, your machine can recognize it as appropriate. How should responses go out? If the IPs are v4 /32 each, the response cannot go out that way. There is no "way" there. If your upstream network allows it, your server can use the v4 /32 as the return address, while sending out to the default router. But you must have an interface which sits on the same network as the default router. Note that you are never deleting the IP that your upstream assigned you. Here's what to do after install: ip addr add $IP/32 dev eth0 that should be all you need, unless there are other things you aren't telling us. -dsr-
