[Olsr-dev] Asymmetric ipip not working

[Sven-Ola Tuecke]

Hey,

@henning | @markus: you must have it at least running. I'm too stupid 
obviously. Here's a manual example (without olsrd, two PCs with linux-2.6)

PC-cli has 192.168.65.110 on wlan0, PC-srv has 192.168.65.67 on eth0
No other routes nor interfaces (besides lo), no iptables, olsrd etc.

On PC-srv, I enter:
-------------------
sysctl -w \
  net.ipv4.ip_forward=1 \
  net.ipv4.conf.all.rp_filter=0 \
  net.ipv4.conf.eth0.rp_filter=0 \
  net.ipv4.conf.all.send_redirects=0
ip addr add dev lo 192.168.11.11
# I need a ping target
ping -c 1 192.168.11.11
# works
modprobe ipip
ip link set dev tunl0 up
tcpdump -ni tunl0
# ok - waits and shows nothing

on PC-cli, I enter:
------------------
ping -c 1 192.168.11.11
# unreachable

ip route add 192.168.11.0/24 dev wlan0
ping -c 1 192.168.11.11
ip route del 192.168.11.0/24 dev wlan0
# works, so no firewall in the way

sysctl -w \
  net.ipv4.ip_forward=1 \
  net.ipv4.conf.all.rp_filter=0 \
  net.ipv4.conf.wlan0.rp_filter=0 \
  net.ipv4.conf.all.send_redirects=0
modprobe ipip
ip tunnel add ipip mode ipip local 192.168.65.110 remote 192.168.65.67
ip link set dev ipip up
ip route add 192.168.11.0/24 dev ipip
ping -c 1 192.168.11.11
# I see the ping via ipip on PC-srv(dev tunl0), but no answer packet

So I need to ask again: what's missing?

// Sven-Ola