icmp packets on em larger than 1472

[Kirill Yelizarov]

Hi,

All my em cards running 8.1 stable don't reply to icmp echo requests packets larger than 1472 bytes.

On stable 7.2 the same hardware works as expected:
# ping -s 1500 192.168.64.99
PING 192.168.64.99 (192.168.64.99): 1500 data bytes
1508 bytes from 192.168.64.99: icmp_seq=0 ttl=63 time=1.249 ms
1508 bytes from 192.168.64.99: icmp_seq=1 ttl=63 time=1.158 ms

Here is the dump on em interface
15:06:31.452043 IP 192.168.66.65 > *****: ICMP echo request, id 28729, seq 5, length 1480
15:06:31.452047 IP 192.168.66.65 > ****: icmp
15:06:31.452069 IP **** > 192.168.66.65: ICMP echo reply, id 28729, seq 5, length 1480
15:06:31.452071 IP *** > 192.168.66.65: icmp
 
Same ping from same source (it's a 8.1 stable with fxp interface) to em card running 8.1 stable
#pciconf -lv
em0 at pci0:3:4:0:	class=0x020000 card=0x10798086 chip=0x10798086 rev=0x03 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Dual Port Gigabit Ethernet Controller (82546EB)'
    class      = network
    subclass   = ethernet

# ping -s 1472 192.168.64.200
PING 192.168.64.200 (192.168.64.200): 1472 data bytes
1480 bytes from 192.168.64.200: icmp_seq=0 ttl=63 time=0.848 ms
^C

# ping -s 1473 192.168.64.200
PING 192.168.64.200 (192.168.64.200): 1473 data bytes
^C
--- 192.168.64.200 ping statistics ---
4 packets transmitted, 0 packets received, 100.0% packet loss

And here is it's dump on em card
5:11:15.191496 IP 192.168.66.65 > *****: ICMP echo request, id 33593, seq 0, length 1480
15:11:15.191534 IP 192.168.66.65 > *****: icmp
15:11:16.192119 IP 192.168.66.65 > *****: ICMP echo request, id 33593, seq 1, length 1480
15:11:16.192156 IP 192.168.66.65 > ******: icmp

igb cards on 8.1 stable are not affected

Regards,
Kirill