It is correct. I'm using openwrt and, at the moment, without -M option. 1500byte packets work, with fragmentation. However, my TCP packets are small (about 60bytes). I have verified TCPDump file and packets arrive. It seems that the Linux IP stack does not forward them to the application. Moreover, if I disable batman on B1-GW1 link, it works
andrea
2009/10/5 Sven Eckelmann sven.eckelmann@gmx.de
a wrote:
The ping with 1500 byte packets works.
How can you send 1500 bytes packets with an mtu of 1476? Do the test with `ping -M do -s 1472 IP` (this should create an 1500 bytes packet and disables fragmentation).
The three nodes are connected in this way: B1 --- batman --- GW1 ------- EX1 eth1 on B1 and GW1 is managed by batman. eth2 on gw1 not. The IP configuration is:
B1: # ip a eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 52:54:00:00:20:01 brd ff:ff:ff:ff:ff:ff bat0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1476 qdisc pfifo_fast state UNKNOWN qlen 1000 link/ether 00:ff:ad:e2:6f:dd brd ff:ff:ff:ff:ff:ff inet 192.168.100.2/24 brd 192.168.100.255 scope global bat0 # ip r 192.168.100.0/24 dev bat0 proto kernel scope link src 192.168.100.2 default via 192.168.100.3 dev bat0
Best regards, Sven