pktgen udp doesn't work over freebsd gateway

[Sebastian Mellmann]

Hello everyone!

I'm using 'pktgen' [1] under linux to generate packets.


My topology looks like this:

(linux-box #1) <---> (em0 - freebsd-gateway - em1) <---> (linux-box #2)

I want to send packets from linux-box #1 to linux-box #2 over the free-bsd
gateway.
The problem is that I can see the packets on em0, but not on em1.
I assume there's a configuration missing on the BSD machine, because it
seems it just drops the packets hence doesn't forward them to linux-box
#2.

rc.conf:
gateway_enable="YES"
keymap="german.iso"
sshd_enable="YES"
firewall_enable="YES"
firewall_type="OPEN"
firewall_logging="YES"

Default option for ipfw is to accept packets.

tcpdump em0:
11:42:36.334798 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334802 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334805 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334807 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334810 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334813 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334816 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334819 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334821 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18
11:42:36.334824 IP (tos 0x0, ttl 32, id 129, offset 0, flags [none], proto
UDP (17), length 46) 192.168.5.1.9 > 192.168.7.1.9: [no cksum] UDP, length
18

tcpdump em1:
nothing.


Is there any sysctl variable that needs to be set?

Connectivity between the boxes is definately working (tested with ping,
iperf etc.).


Regards,
Sebastian

[1] http://www.linuxfoundation.org/en/Net:Pktgen