Bridging Public Clouds with CloudRouter

Owned by Chandrasekar Kannan
Last updated: Apr 28, 2015
5 min read

 

The goal of this article is to showcase how to utilize CloudRouter to setup a secure Virtual Private Network (VPN) IPsec tunnel between two public clouds environments one in AWS EC2 and one in Google Cloud.

 

Topology

 

Setup in AWS EC2

Launch CloudRouter

Find the CloudRouter image and launch it in AWS EC2. Instructions to launch are here - http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/launching-instance.html

Edit Firewall Rules

We have to allow traffic on ports 500 and 4500 for the ipsec tunnel.

Installing libreswan

yum -y install libreswan

 

Editing /etc/ipsec.conf

## general configuration parameters ##
 
config setup
        plutodebug=all
        plutostderrlog=/var/log/pluto.log
        protostack=netkey
        nat_traversal=yes
        virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/16
        ## disable opportunistic encryption ##
        oe=off
 
## connection definition ##
conn demo-connection
        authby=secret
        auto=start
        ike=3des-md5
        ## phase 1 ##
        keyexchange=ike
        ## phase 2 ##
        phase2=esp
        phase2alg=3des-md5
        compress=no
        pfs=yes
        type=tunnel
        left=172.31.13.92 ## EC2 internal IP Address
        leftsourceip=52.8.28.128 ## EC2 external IP Address
        leftsubnet=172.31.0.0/16 ## EC2 Internal subnet/mask
        leftnexthop=%defaultroute
        right=104.199.167.94 ## Google Cloud External IP Address
        rightsubnet=10.240.0.0/16 ## Google Cloud Internal Subnet/mask
        rightsourceip=10.240.155.115 ## Google Cloud Internal IP Address
        forceencaps=yes

 

Editing /etc/ipsec.secrets

52.8.28.128 %any : PSK "this is my pre shared key"
172.31.13.92 %any : PSK "this is my pre shared key"
include /etc/ipsec.d/*.secrets


Start ipsec daemon

# systemctl start ipsec

 

Setup in Google Cloud

Launching CloudRouter

Find the raw image of CloudRouter provided here - https://cloudrouter.org/getting-started/ and launch it on Google Cloud. Instructions to import your image to Google Cloud are located here - https://cloud.google.com/compute/docs/images#import_an_image

Edit Firewall Rules

We have to open up traffic on ports 500 and 4500 for IPsec tunnel.

Editing /etc/ipsec.conf

## general configuration parameters ##
 
config setup
        plutodebug=all
        plutostderrlog=/var/log/pluto.log
        protostack=netkey
        nat_traversal=yes
        virtual_private=%v4:10.0.0.0/8,%v4:192.168.0.0/16,%v4:172.16.0.0/16
        ## disable opportunistic encryption ##
        oe=off
 
## connection definition ##
conn demo-connection
        authby=secret
        auto=start
        ike=3des-md5
        ## phase 1 ##
        keyexchange=ike
        ## phase 2 ##
        phase2=esp
        phase2alg=3des-md5
        compress=no
        pfs=yes
        type=tunnel
        left=10.240.155.115 ## Internal Google IP address
        leftid=104.199.167.94 ## External Google IP address
        leftsubnet=10.240.0.0/16 ## Internal Google Subnet/mask
        leftnexthop=%defaultroute
        right=52.8.28.128 ## External EC2 IP Address
        rightsubnet=172.31.0.0/20 ## Internal EC2 Subnet/mask
        rightid=172.31.13.92 ## Internal EC2 IP address
        forceencaps=yes

 

Editing /etc/ipsec.secrets

104.199.167.94 %any : PSK "this is my pre shared key"
10.240.155.115 %any : PSK "this is my pre shared key"
include /etc/ipsec.d/*.secrets

 

Start ipsec daemon

# systemctl start ipsec

Test Connectivity between AWS EC2 and Google Cloud

Check Status of IPsec Tunnel

/var/log/pluto.log
[root@ip-172-31-13-92 ~]# grep -i established /var/log/pluto.log 
"demo-connection" #1: STATE_MAIN_I4: ISAKMP SA established {auth=PRESHARED_KEY cipher=oakley_3des_cbc_192 integ=md5 group=MODP2048}
"demo-connection" #2: STATE_QUICK_I2: sent QI2, IPsec SA established tunnel mode {ESP/NAT=>0x3d420cd3 <0x94844801 xfrm=3DES_0-HMAC_MD5 NATOA=none NATD=104.199.167.94:4500 DPD=passive}
"demo-connection" #3: STATE_MAIN_R3: sent MR3, ISAKMP SA established {auth=PRESHARED_KEY cipher=oakley_3des_cbc_192 integ=md5 group=MODP2048}
"demo-connection" #4: STATE_QUICK_R2: IPsec SA established tunnel mode {ESP/NAT=>0x9ed968b4 <0xa0c6cbbc xfrm=3DES_0-HMAC_MD5 NATOA=none NATD=104.199.167.94:4500 DPD=passive}
"demo-connection" #5: STATE_MAIN_R3: sent MR3, ISAKMP SA established {auth=PRESHARED_KEY cipher=oakley_3des_cbc_192 integ=md5 group=MODP2048}

 

Check availability of routes

 

[root@ip-172-31-13-92 ~]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         172.31.0.1      0.0.0.0         UG    0      0        0 eth0
10.240.0.0      172.31.0.1      255.255.0.0     UG    0      0        0 eth0
172.31.0.0      0.0.0.0         255.255.240.0   U     0      0        0 eth0

 

Ping Test from EC2 to Google Cloud

[root@ip-172-31-13-92 log]# ping 10.240.155.115
PING 10.240.155.115 (10.240.155.115) 56(84) bytes of data.
64 bytes from 10.240.155.115: icmp_seq=1 ttl=64 time=273 ms
64 bytes from 10.240.155.115: icmp_seq=2 ttl=64 time=272 ms
64 bytes from 10.240.155.115: icmp_seq=3 ttl=64 time=272 ms
^C
--- 10.240.155.115 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 272.920/273.111/273.455/0.243 ms