On Tue, Mar 17, 2026 at 08:32:25PM +0100, Kisp??l Zsolt wrote: > Hello, > > I try to configure OpenBSD 7.8 to act as DHCP relay with multiple > interfaces. > > I have the following setup: one Internet facing gateway as well as DHCP > server (hostname: apu4d4) and an internal router (hostname:alix2c3) > > ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? ?? vlan4_192 168.4.254/24 > ??/ > ?? ?? ?? ?? ?? ?? ?? +-----------+ ??+------------------+/ > ?? ?? ?? ?? ?? ?? ?? |?? ?? ?? ?? ?? ??|?? ??192.168.1.0/24?? | | > INTERNET------+?? APU4D4?? ??+-------------------+vr1?? ALIX2C3 > ??vr0+----vlan5_192.168.5.126/25 > ?? ?? ?? ?? ?? ?? ?? |GW&DHCPsrv |.254?? ?? ?? ?? ?? ?? ??.1| Internal > router?? | > ?? ?? ?? ?? ?? ?? ?? +-----------+ ??+------------------+\ > ??\ > ?? vlan6_192.168.5.254/25 > > Config looks like this: > > alix2c3$ cat /etc/hostname.vr1 > media autoselect > -inet6 > inet 192.168.1.1 255.255.255.0 192.168.1.255 > description ===VLAN_1=== > !route -n add -nostatic -priority 2 default 192.168.1.254 > up > > alix2c3$ cat /etc/hostname.vr0 > media autoselect > -inet6 > -inet > description ===Virtualization_VLANs=== > up > > alix2c3$ cat /etc/hostname.vlan4 > inet 192.168.4.254 255.255.255.0 192.168.4.255 parent vr0 vnetid 4 > description ===Interface_VLAN4=== > up > > alix2c3$ cat /etc/hostname.vlan5 > inet 192.168.5.126 255.255.255.128 192.168.5.127 parent vr0 vnetid 5 > description ===Interface_VLAN5=== > up > > alix2c3$ cat /etc/hostname.vlan6 > inet 192.168.5.254 255.255.255.128 192.168.5.255 parent vr0 vnetid 6 > description ===Interface_VLAN6=== > up > alix2c3$ > > I would like to use alix2c3 as DHCP relay for the subnets on vlan4, vlan5 > and vlan6. I found forum posts where more interfaces was provided to > dhcrelay but I still get an error message: > > alix2c3$ doas dhcrelay -d -i vlan4 -i vlan5 -i vlan6 192.168.1.254 > usage: dhcrelay [-dor] [-C circuit-id] [-R remote-id] -i interface > ?? ?? ?? ?? destination ... > > Same if I give the interface name instead of the destination DHCP server IP > > alix2c3$ doas dhcrelay -d -i vlan4 -i vlan5 -i vlan6 vr1 > usage: dhcrelay [-dor] [-C circuit-id] [-R remote-id] -i interface > ?? ?? ?? ?? destination ... > alix2c3$ > > If I give only one interface as then there is no issue. > > What do I do wrong? Does OpenBSD dhcrelay support multiple interfaces at > all?
no, you have a run a dhcrelay per interface. cheers, dlg
