ICMP packets lost with an interval of 30 packets

ICMP packets lost with an interval of 30 packets

[HouCheng Lee]

Hi,everyone:

I have ported the 2.4.18 kernel to a board of MIPS arch.
When I "make menuconfig", just turn on connection tracking
option,
and let the MIPS board run, 
I got a strange icmp echo and reply pattern.

I config my eth0 of MIPS board "192.168.1.254",
and ping it from my computer with IP,"192.168.1.100".
I got the following messages:
------------------------------------------------------------
PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data.
64 bytes from 192.168.1.254: icmp_seq=1 ttl=255 time=4.80 ms
64 bytes from 192.168.1.254: icmp_seq=31 ttl=255 time=1.62 ms
64 bytes from 192.168.1.254: icmp_seq=61 ttl=255 time=1.94 ms
............................................
-------------------------------------------------------------
And when I change the "ICMP_TIMEOUT" variable in
"ip_conntrack_proto_icmp.c" from (30*Hz) to (20*Hz),
the echo and reply looks like following:
------------------------------------------------------------
PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data.
64 bytes from 192.168.1.254: icmp_seq=1 ttl=255 time=4.80 ms
64 bytes from 192.168.1.254: icmp_seq=21 ttl=255 time=1.62 ms
64 bytes from 192.168.1.254: icmp_seq=41 ttl=255 time=1.94 ms
............................................
------------------------------------------------------------- 

I had done the same thing on x86 arch and everything was ok.
I do not know if there are some arch dependent code in
netfilter,
or I have missed some relevant modules or there are bugs in
the hardware.
Please give me some suggestion. 
Thanks.