Hello,
I have a FreeBSD 4.6-STABLE system. 256MB RAM. My NIC is 3C905b-tx. My kernel includes
only this nic driver compiled in. Hardware is 200mmx, IDE disk system. My switch is
10/100 and non-managable.
My problem was first slow samba performance. After I tried ftp upload and download. I
see that my download speeds are reasonable but not fast enough. And, don't mention
about uploads. 40kb/sec average.
I decided to tcpdump during my upload and downloads. My command line was: tcpdump -i
xl0 -l -vv
I myself do not understand this type of outputs usually. But, one thing is very
interesting that there is a lot of bad checksum errors. So, I decided to post it to
the list for somebody's advice.
I do not think the problem is ethernet card. My subsustem is completely 3c905b or c
class NICs. I can copy 650mb over ms network really very fast. Also, I do not think
this is because of bad cabling. As I said above I have fast speeds. And, I changed
this cable time to time for another reasons.
I just want to ask where should I look? What should I change? I read about complains
about 3c905 NICs. On the other hand I read very proudy words about that NICs, too.
Here is some part of my ftp upload dump. There are bad checksum messages during
download, but not that much.
If anyone interests. I can post the complete dumps seperately. Two files are 200kb in
tarred gzipped format.
Thanks in advance.
08:59:40.863211 ertank.1700 ozlerplastik.com.telnet: . [tcp sum ok]
2115353:2115353(0) ack 3548812291 win 64773 (DF) (ttl 128, id 20291, len 40)
08:59:40.863411 ozlerplastik.com.telnet ertank.1700: P [bad tcp cksum a310!]
1:28(27) ack 0 win 65535 (DF) [tos 0x10] (ttl 64, id 57149, len 67, bad cksum 0!)
08:59:40.929785 ozlerplastik.com.squid halil.1170: P 50714828:50716276(1448) ack
1080811 win 65535 (DF) (ttl 64, id 57151, len 1488, bad cksum 0!)
08:59:41.032874 ozlerplastik.com.squid halil.1170: P 1448:2896(1448) ack 1 win 65535
(DF) (ttl 64, id 57153, len 1488, bad cksum 0!)
08:59:41.033360 halil.1170 ozlerplastik.com.squid: . [tcp sum ok] 1:1(0) ack 2896
win 8760 (DF) (ttl 128, id 35588, len 40)
08:59:41.073165 ertank.1700 ozlerplastik.com.telnet: . [tcp sum ok] 0:0(0) ack 28
win 64746 (DF) (ttl 128, id 20547, len 40)
08:59:41.345335 halil.1170 ozlerplastik.com.squid: F [tcp sum ok] 1:1(0) ack 6769
win 7783 (DF) (ttl 128, id 36100, len 40)
08:59:41.345468 ozlerplastik.com.squid halil.1170: . [bad tcp cksum db27!]
6769:6769(0) ack 2 win 65535 (DF) (ttl 64, id 57160, len 40, bad cksum 0!)
08:59:41.345814 ozlerplastik.com.squid halil.1170: F [bad tcp cksum da27!]
6769:6769(0) ack 2 win 65535 (DF) (ttl 64, id 57161, len 40, bad cksum 0!)
08:59:41.346002 halil.1170 ozlerplastik.com.squid: . [tcp sum ok] 2:2(0) ack 6770
win 7783 (DF) (ttl 128, id 36356, len 40)
08:59:41.351478 64.12.25.28.aol halil.1072: . [tcp sum ok] 1363979447:1363979447(0)
ack 506585 win 16384 (DF) (ttl 43, id 24233, len 40, bad cksum 0!)
08:59:41.351654 halil.1072 64.12.25.28.aol: . [tcp sum ok] 1:1(0) ack 1 win 8186
(DF) (ttl 128, id 36612, len 40)
08:59:43.163120 11aec257.00:50:8b:8b:9f:f3.9001 0.ff:ff:ff:ff:ff:ff.9001: ipx-#9001
43
08:59:44.261756 11aec257.00:50:8b:8b:9f:f3.9001 0.ff:ff:ff:ff:ff:ff.9001: ipx-#9001
99
08:59:44.261774 4c574182.00:50:8b:8b:9f:f3.9001 0.ff:ff:ff:ff:ff:ff.9001: ipx-#9001
99
08:59:44.828932 4c574182.00:00:21:4e:89:e8.553 70001600.88:09:65:04:70:00.553:
ipx-nwlink-dgm 197
08:59:45.319779 ertank.1075 ozlerplastik.com.ftp: S [tcp sum ok]
77680920:77680920(0) win 65535 mss 1460,nop,nop,sackOK (DF) (ttl 128, id 26179, len
48)
08:59:45.319974 ozlerplastik.com.ftp ertank.1075: S [bad tcp cksum e914!]
1215290833:1215290833(0) ack 77680921 win 65535 mss 1460 (ttl 64, id 57163, len 44,
bad cksum 0!)
08:59:45.320118 ertank.1075 ozlerplastik.com.ftp: . [tcp sum ok] 1:1(0) ack 1 win
65535 (DF) (ttl 128, id 26435, len 40)
08:59:45.353331 ozlerplastik.com.ftp ertank.1075: P 1:52(51) ack 1 win 65535 (DF)
(ttl 64, id 57164, len 91, bad cksum 0!)
08:59:45.525091 4c574182.00:50:8b:8b:9f:f3.9001 0.ff:ff:ff:ff:ff:ff.9001: ipx-#9001
43
08:59:45.532519 ertank.1075 ozlerplastik.com.ftp: . [tcp sum ok] 1:1(0) ack 52 win
65484 (DF) (ttl 128, id 26691, len 40)
08:59:46.818751 ertank.1075 ozlerplastik.com.ftp: P [tcp sum ok] 1:11(10) ack 52 win
65484 (DF) (ttl 128, id 26947, len 50)
08:59:46.819211 ozlerplastik.com.ftp ertank.1075: P [bad tcp cksum ffe4!] 52:86(34)
ack 11 win 65535 (DF) (ttl 64, id 57165, len 74, bad cksum 0!)
08:59:46.937788 ertank.1075 ozlerplastik.com.ftp: . [tcp sum ok] 11:11(0) ack 86 win
65450 (DF) (ttl 128, id 27203, len 40)
08:59:47.694187 ozlerplastik.com.gds_db zeynep.1066: P [bad tcp cksum c72f!]
1280308047:1280308051(4) ack 2174202 win 65535 (DF) (ttl 64, id 57166, len 44, bad
cksum 0!)
08:59:47.834264 zeynep.1066 ozlerplastik.com.gds_db: . [tcp sum ok] 1:1(0) ack 4 win
8456 (DF) (ttl 128, id 32260, len 40)
08:59:48.640388 ertank.1075