This is "pxn2" (please ignore the misleading host name "proxmox1")!

root@proxmox1:~# cat /etc/debian_version
7.7
root@proxmox1:~# uname -a
Linux proxmox1 2.6.32-34-pve #1 SMP Sat Nov 8 09:38:26 CET 2014 x86_64 GNU/Linux
root@proxmox1:~# ifconfig
bond0     Link encap:Ethernet  HWaddr 02:00:0a:01:01:c7
          inet addr:172.16.1.1  Bcast:172.16.1.255  Mask:255.255.255.0
          inet6 addr: fe80::aff:fe01:1c7/64 Scope:Link
          UP BROADCAST RUNNING MASTER MULTICAST  MTU:1462  Metric:1
          RX packets:71 errors:0 dropped:0 overruns:0 frame:0
          TX packets:45 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:3220 (3.1 KiB)  TX bytes:3002 (2.9 KiB)

eth0      Link encap:Ethernet  HWaddr d0:4c:c1:00:2c:7a
          inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::d24c:c1ff:fe00:2c7a/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:6716 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6983 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:748507 (730.9 KiB)  TX bytes:1140597 (1.0 MiB)

eth1      Link encap:Ethernet  HWaddr d0:4c:c1:00:2c:7b
          inet addr:10.1.1.199  Bcast:10.1.1.255  Mask:255.255.255.0
          inet6 addr: fe80::d24c:c1ff:fe00:2c7b/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:39630 errors:0 dropped:0 overruns:0 frame:0
          TX packets:37759 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:8325933 (7.9 MiB)  TX bytes:7964767 (7.5 MiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:14211 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14211 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1426425 (1.3 MiB)  TX bytes:1426425 (1.3 MiB)

venet0    Link encap:UNSPEC  HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
          inet6 addr: fe80::1/128 Scope:Link
          UP BROADCAST POINTOPOINT RUNNING NOARP  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:3 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

vpn_br    Link encap:Ethernet  HWaddr 02:00:0a:01:01:c7
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1462  Metric:1
          RX packets:71 errors:0 dropped:0 overruns:0 frame:0
          TX packets:45 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:3220 (3.1 KiB)  TX bytes:3002 (2.9 KiB)

vpn_gre_pxn1 Link encap:Ethernet  HWaddr 06:c3:29:46:ee:94
          inet6 addr: fe80::4c3:29ff:fe46:ee94/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1462  Metric:1
          RX packets:110 errors:0 dropped:0 overruns:0 frame:0
          TX packets:97 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:7732 (7.5 KiB)  TX bytes:6846 (6.6 KiB)

root@proxmox1:~# ip route show
192.168.1.0/24 dev eth0  proto kernel  scope link  src 192.168.1.1
172.16.1.0/24 dev bond0  proto kernel  scope link  src 172.16.1.1
10.1.1.0/24 dev eth1  proto kernel  scope link  src 10.1.1.199
default via 10.1.1.11 dev eth1
root@proxmox1:~# cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.6.0 (September 26, 2009)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: vpn_br
MII Status: up
MII Polling Interval (ms): 1000
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: vpn_br
MII Status: up
Speed: Unknown
Duplex: Unknown
Link Failure Count: 0
Permanent HW addr: 06:c3:29:46:ee:94
Slave queue ID: 0
root@proxmox1:~# brctl show
bridge name     bridge id               STP enabled     interfaces
vpn_br          8000.02000a0101c7       no              vpn_gre_pxn1