Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #262963

Re: Debian installer refuses to setup IP address if gateway is no in the same subnet

Show all headers | View raw

On 10/31/23 01:18, Dan Ritter wrote:
> 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.


Here you find an example of ISP documentation describing the fact the IP 
address is not in the same subnet as the gateway: 
https://help.ovhcloud.com/csm/en-dedicated-servers-network-bridging?id=kb_article_view&sysparm_article=KB0043731#step-4-configure-the-virtual-machines

|ADDITIONAL_IP can be any single IP you purshased, and you see the 
netmask set to|

|255.255.255.255 There is no mention to the host (VMWare) IP address in 
the VM|

Back to linux.debian.user | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

Debian installer refuses to setup IP address if gateway is no in the  same subnet Mihamina RKTMB <mihamina@atscom.io> - 2023-10-30 23:00 +0100
  Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Jeffrey Walton <noloader@gmail.com> - 2023-10-30 23:10 +0100
    Re: Debian installer refuses to setup IP address if gateway is no  in the same subnet "Marco M." <mm@dorfdsl.de> - 2023-10-31 11:20 +0100
      Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Reco <recoverym4n@enotuniq.net> - 2023-10-31 15:10 +0100
  Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Dan Ritter <dsr@randomstring.org> - 2023-10-30 23:40 +0100
    Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Mihamina RKTMB <mihamina@atscom.io> - 2023-10-31 14:20 +0100
      Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Dan Ritter <dsr@randomstring.org> - 2023-10-31 15:10 +0100
        Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Mihamina RKTMB <mihamina@atscom.io> - 2023-10-31 15:40 +0100
  Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Henning Follmann <hfollmann@itcfollmann.com> - 2023-10-31 13:40 +0100
    Re: Debian installer refuses to setup IP address if gateway is no  in the same subnet "Marco M." <mm@dorfdsl.de> - 2023-10-31 14:20 +0100
    Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Mihamina RKTMB <mihamina@atscom.io> - 2023-10-31 15:00 +0100
      Re: Debian installer refuses to setup IP address if gateway is no in  the same subnet Henning Follmann <hfollmann@itcfollmann.com> - 2023-10-31 16:10 +0100

csiph-web