GRE Tunnel routing issue in Linux CentOS

1
votes

I am creating GRE Tunnel between two Linux (CentOS6) servers using below steps.

On the master server:

chkconfig iptables off

service iptables stop

sysctl -w net.ipv4.conf.default.rp_filter=0

modprobe ip_gre

ip tunnel add tun1 mode gre remote 98.123.87.97 local 106.61.58.98 ttl 255

ip addr add 10.0.1.0/24 dev tun1

ip link set dev tun1 up

ip addr add 98.123.87.95/27 dev eth0

On the slave server:

chkconfig iptables off

service iptables stop

sysctl -w net.ipv4.ip_forward=1

sysctl -w net.ipv4.conf.all.forwarding=1

sysctl -w net.ipv4.conf.proxy_arp=1

sysctl -w net.ipv4.conf.all.proxy_arp=1

sysctl -w net.ipv4.conf.eth0.rp_filter=0

sysctl -w net.ipv4.conf.default.rp_filter=0

modprobe ip_gre

ip tunnel add tunx mode gre remote 106.61.58.98 local 98.123.87.97 ttl 255

ip addr add 10.0.2.0/24 dev tun0

ip link set tunx up

ip route add 98.123.87.95/27 dev tun0

I need to add slave server's IP into the on my master server, I am getting the ping response form tunnelled IPs (Slave Server's IP) and when I am trying to SSH the tunnelled IP (Slave IP) I am reaching to Masters(this is what I want).

Problem is when I am trying to send outgoing traffic like DNS query by Tunnelled IP(Slave IP) I am getting time out request.

I guess this is routing issue of one of my server. Any idea what should i do to get through my outgoing traffic by tunnelled IPs?

Thanks,

1
linuxnetworkingroutingtunneltunneling

1 Answers

1
votes

Are you really adding 10.0.1.0/24 address? This is a network address, looks like mistake. Also, you shuold add default route(or route to dns servers or whatever you want) on client machine through your tunnel with gateway=another_end_of_tunnel. Don't forget to add static route to your machine if you don't want to loose connection, before adding default route!