First question here on serverfault, so kind of a newbie, all feedback is welcome.
I have a dedicated server running Debian GNU/Linux 8.4 (jessie) with one public IP and multiple additional public IPs assigned to it. Server has two NICs, eth0 and eth1, server main public IP is routed to eth1). All additional public IPs are assigned to alias interfaces (eth1:0, eth1:1, eth1:2 etc) except for 1 IP, which I want to assign to a KVM guest, but in a routed networking configuration (the datacenter does not allow multiple MAC addresses to connect to the switch ports, so I have no option but to use routing instead of bridging).
I have set up the interface aliases, and I can assign the corresponding public IPs to different virtualhosts under Apache 2.4 (through the use of ISPConfig 3 web hosting control panel). The virtualhosts work fine in this configuration. Yet, when I try to add a routed network bridge (vmbr0) and route the KVM guest traffic through it, I lose connectivity and have to reboot the server. After reboot, the server works for some time (minutes), and loses connectivity again. I can't seem to figure out what is wrong.
Note: I have followed the Hetzner guide [https://wiki.hetzner.de/index.php/Netzkonfiguration_Debian/en#Routed_.28brouter.29] on another host system, and the KVM guests work alright. Only difference is the aliased interfaces I also need to have in this case.
I have created the bridge interface with:
brctl addbr vmbr0
prior to restarting networking with
Network configuration for the host system:
auto lo iface lo inet loopback auto eth0 iface eth0 inet manual auto eth1 iface eth1 inet static address AAA.AAA.AAA.AAA netmask 255.255.255.0 gateway AAA.AAA.AAA.1 pointopoint AAA.AAA.AAA.1 auto eth1:1 iface eth1:1 inet static address BBB.BBB.BBB.BBB netmask 255.255.255.255 auto eth1:2 iface eth1:2 inet static address CCC.CCC.CCC.CCC netmask 255.255.255.255 auto eth1:3 iface eth1:3 inet static address DDD.DDD.DDD.DDD netmask 255.255.255.255 auto eth1:4 iface eth1:4 inet static address EEE.EEE.EEE.EEE netmask 255.255.255.255 auto eth1:5 iface eth1:5 inet static address FFF.FFF.FFF.FFF netmask 255.255.255.255 auto eth1:6 iface eth1:6 inet static address GGG.GGG.GGG.GGG netmask 255.255.255.255 auto eth1:7 iface eth1:7 inet static address HHH.HHH.HHH.HHH netmask 255.255.255.255 auto eth1:8 iface eth1:8 inet static address III.III.III.III netmask 255.255.255.255 auto eth1:9 iface eth1:9 inet static address JJJ.JJJ.JJJ.JJJ netmask 255.255.255.255 auto eth1:10 iface eth1:10 inet static address KKK.KKK.KKK.KKK netmask 255.255.255.255 # KVM VM routed (bridge) interface for single IPs auto vmbr0 iface vmbr0 inet static address AAA.AAA.AAA.AAA netmask 255.255.255.0 bridge_ports none bridge_stp off bridge_fd 0 # up ip route add ip1_goes_here/32 dev vmbr0 # up ip route add ip2_goes_here/32 dev vmbr0 # up ip route add ip3_goes_here/32 dev vmbr0
I haven't yet created the KVM guest machine. Perhaps I should have a running VM and traffic routed to it BEFORE bringing the vmbr0 bridge up for some reason? If I can make this work, I'll add additional KVM guests with additional public IPs assigned to them.
Last thing to add is, this is a server already running some websites, so if what I need can be done and with minimum downtime that'd be great!