http://serverfault.com/questions/566198/transparent-ethernet-over-gre-not-forwarding-traffic

http://backreference.org/2013/07/23/gre-bridging-ipsec-and-nfqueue/

I am running on Linux 2.6.30.9 and have been trying to setup a transparent ethernet over GRE tunnel. The network topology used is as follows:

I want to bridge PC1 and PC2 using Transparent Ethernet over GRE. RouterA is connected to internet via ppp0 as RouterB. Both internet connections are PPPOE (PPPoEoA PVCs).

So i do:

In RouterA (linux 2.6.30.9):

ip link add testgre type gretap remote 193.152.243.206 local 95.121.205.77 ttl 255
brctl addif br0 testgre
ip link set testgre up

In RouterB (linux 2.6.30.9):

ip link add testgre type gretap remote 95.121.205.77 local 193.152.243.206 ttl 255
brctl addif br0 testgre
ip link set testgre up

Some commands output:

In RouterA (similar output in RouterB):

# ip link show testgre
36: testgre: <BROADCAST,MULTICAST,PROMISC,UP,LOWER_UP> mtu 1442 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 5f:79:cd:4d:c6:57 brd c1:98:f3:ce:ff:ff

# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.5f79cd4dc657       no              eth0.5
                                                        eth0.4
                                                        eth0.3
                                                        eth0.2
                                                        wlan0
                                                        testgre

Then i do PING request from PC1 to PC2:

ping 192.168.1.33