icmp packets on em larger than 1472 [SEC=UNCLASSIFIED]

[Wilkinson, Alex]

    0n Wed, Nov 10, 2010 at 04:21:12AM -0800, Kirill Yelizarov wrote: 

    >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

works fine for me:

FreeBSD 8.1-STABLE #0 r213395

em0 at pci0:0:25:0:class=0x020000 card=0x3035103c chip=0x10de8086 rev=0x02 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = 'Intel Gigabit network connection (82567LM-3 )'
    class      = network
    subclass   = ethernet

#ping -s 1473 host
PING host(192.168.1.1): 1473 data bytes
1481 bytes from 192.168.1.1: icmp_seq=0 ttl=253 time=31.506 ms
1481 bytes from 192.168.1.1: icmp_seq=1 ttl=253 time=31.493 ms
1481 bytes from 192.168.1.1: icmp_seq=2 ttl=253 time=31.550 ms
^C

   -Alex

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