Xen VPS with 2 IPs from 2 different subnets

Question

I am new to Xen and I am trying to understand how to add 2 different IPs on the same guest VPS.

First, I am going to explain my node setup, which is a physical server with 32GB RAM and 2 NICs on it. The first NIC has a public IP 82.XXX.YYY.ZZZ and the second NIC is for an internal network that connects to a cPanel server - private IP 192.168.XXX.YYY.

From what I've tested until now, I only managed to create a VPS that uses either the public network or the private network, but not both. If I create the VPS with either the public IP or the private IP, I can ping them and also connect through SSH.

But for example, if I create a VPS that uses some IP from the same subnet as the node (82.XXX.YYY.ZZZ) and then try to add a private IP, I cannot ping the private IP from the internal network, and viceversa, if I create a VPS with private IP (192.168.XXX.YYY), I can connect to it and ping it from the internal network, but if I add a public IP, I cannot ping it or connect to it.

Also, I don't know if this information will help in this issue, but I use SolusVM for VPS administration (create VPS, IP allocation, delete VPS, etc.).

Please let me know what other info do I need to provide to solve this problem.

Answer 1

Configure bridge network:

Edit /etc/network/interfaces
# vi /etc/network/interfaces
...
auto eth0
iface eth0 inet manual

auto br0
iface br0 inet static
        address [ipv4]
        netmask [netmask]
        network [network]
        broadcast [broadcast]
        gateway [ipv4gateway]
        bridge_ports eth0
        bridge_stp on
        bridge_maxwait 0
iface br0 inet6 static
        address [ipv6]
        netmask 64
        dns-nameservers [dnsipv6]
        gateway [ipv6gatewaay]
        autoconf 0
# internal
auto virbr0
iface virbr0 inet static
        address 192.168.0.1
        netmask 255.255.255.0
        broadcast 192.168.0.255
        pre-up brctl addbr virbr0

edit /etc/sysctl.conf.d

net.ipv4.ip_forward = 1
net.ipv6.conf.all.forwarding=1
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0 

Manual adding virbr0

# brctl addbr virbr0
# ifconfig virbr0 192.168.0.1 netmask 255.255.255.0 up  

Install and configure dhcp server for domu Install isc-dhcp-server

# apt-get install isc-dhcp-server 

Edit /etc/default/isc-dhcp-server

INTERFACES="virbr0"
Edit /etc/dhcp/dhcpd.conf
subnet 192.168.0.0 netmask 255.255.255.0 {
  range 192.168.0.10 192.168.0.50;
  option routers 192.168.0.1;
  default-lease-time 600;
  max-lease-time 7200;
}

Restart dhcp server

# service isc-dhcp-server restart

Configuring xen-tool to create domu images edit /etc/xen-tools/xen-tools.conf

#Begin by setting the dir = directive to the directory into which the tools are to create the Xen guest image files:
dir = /home/images
#lvm = myvolgroup -> if using LVM (logical volume management)
install-method = debootstrap
debootstrap-cmd = /usr/sbin/debootstrap
size   = 4G       # Root disk, suffix (G, M, k) required
memory = 512M # Suffix (G, M, k) required
swap   = 1G # Suffix (G, M, k) required
fs     = ext3     # Default file system for any disk
dist   = `jessie` # Default distribution is determined by Dom0's distribution
image  = sparse   # Specify sparse vs. full disk images (file based images only)
# for static
# gateway    = 192.168.1.1
# netmask    = 255.255.255.0
# broadcast  = 192.168.1.255
dhcp=1
bridge = virbr0
genpass_len = 8
passwd = 1
kernel      = /boot/vmlinuz-`uname -r`
initrd      = /boot/initrd.img-`uname -r`
pygrub = 1
mirror = http://debian.mirrors.ovh.net/debian
mirror_jessie = http://http.debian.net/debian
ext4_options     = noatime,nodiratime,errors=remount-ro 
ext3_options     = noatime,nodiratime,errors=remount-ro
ext2_options     = noatime,nodiratime,errors=remount-ro
xfs_options      = defaults
reiserfs_options = defaults
btrfs_options    = defaults
output    = /etc/xen

extension = .cfg

Creating Xen disk image (loopback image) for Xen guest Create xen guest with hostname testa, disk 10G, swap 1G, ram/memory 512M, dhcp, vcpu 3, OS Debiean jessie:

# xen-create-image --hostname testa --size=10Gb --swap=1024Mb --memory=512Mb --vcpu=3  --dist=jessie
Can't exec "jessie": No such file or directory at /usr/share/perl5/Xen/Tools/Common.pm line 100, <FILE> line 134.
Use of uninitialized value $output in scalar chomp at /usr/share/perl5/Xen/Tools/Common.pm line 101, <FILE> line 134.
Use of uninitialized value $output in concatenation (.) or string at /usr/share/perl5/Xen/Tools/Common.pm line 104, <FILE> line 134.

General Information
--------------------
Hostname       :  testa
Distribution   :  jessie
Mirror         :  http://debian.mirrors.ovh.net/debian
Partitions     :  swap            1024Mb (swap)
                  /               10Gb  (ext3)
Image type     :  sparse
Memory size    :  512Mb
Bootloader     :  pygrub

Networking Information
----------------------
IP Address     : DHCP [MAC: 00:16:3E:73:6F:31]


Creating partition image: /home/vmimages/domains/testa/swap.img
Done

Creating swap on /home/vmimages/domains/testa/swap.img
Done

Creating partition image: /home/vmimages/domains/testa/disk.img
Done

Creating ext3 filesystem on /home/vmimages/domains/testa/disk.img
Done
Installation method: debootstrap
Done

Running hooks
Done

No role scripts were specified.  Skipping

Creating Xen configuration file
Done

No role scripts were specified.  Skipping
Setting up root password
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
All done


Logfile produced at:
         /var/log/xen-tools/testa.log

Installation Summary
---------------------
Hostname        :  testa
Distribution    :  jessie
MAC Address     :  00:16:3E:73:6F:31
IP Address(es)  :  dynamic
RSA Fingerprint :  21:12:bb:c3:ad:34:67:6f:cd:a1:7d:d3:ef:ae:95:f5
Root Password   :  N/A

This process take approximate 14 minutes. Run xen guest To run xen guest

# xl create /etc/xen/testa.cfg -c

Routing Internal to internet

# iptables -t nat -A POSTROUTING -o br0 -j MASQUERADE
# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
# iptables -A FORWARD -i virbr0 -o br0 -m state --state RELATED,ESTABLISHED -j ACCEPT
# iptables -A FORWARD -i virbr0 -o br0 -j ACCEPT  
Internet to internal in port xxx into 192.168.0.100 port yyy
# iptables -A PREROUTING -t nat -i br0 -p tcp --dport xxx -j DNAT --to 192.168.0.100:yyy
# iptables -A FORWARD -p tcp -d 192.168.0.100 --dport yyy -j ACCEPT

Make auto-start domu after boot Create symlink into folder /etc/xen/auto

# mkdir /etc/xen/auto
# cd /etc/xen/auto/
# ln -s /etc/xen/testa.cfg

edit /etc/xen/testa.cfg

# vi /etc/xen/testa.cfg
on_xend_stop='shutdown' 
on_xend_start='start'

for complete instruction read: http://www.garasiku.web.id/web/joomla/index.php/debian/80-how-to-install-xen-in-debian-jessie