Some nice folks on the port-macppc list have helped me interpret the
tcpdump output that I have gathered[2].  Apparently, the slow
downloads are because many packets are being lost.  Any ideas what
could cause this type of problem?

-russ


[2] The data I originally included is not sufficient to do a
diagnosis.  I have gathered a better data set which is available at
http://thelonious.dyndns.org/tcpdump.txt


Russell McManus <russell_mcmanus@yahoo.com> writes:

> I've got 1.5.2 installed on a powermac 7300.  Most things are working
> beautifully, but I seem to be getting very slow downloads in the
> territory of 1KB/s[1].  Others on the port-macppc list have reported
> getting nearly 100 times this speed with identical hardware.
> 
> Everything works, it's just really slow.  The powermac is behind a
> Linksys firewall/router combo device.  Other machines behind the same
> firewall, in particular a i386 NetBSD 1.5.2 machine, achieve normal
> download speeds.  Transfers are slow both from the powermac to
> machines on the far side of the firewall, and from the powermac to
> other machines behind the firewall.
> 
> Someone on port-macppc suggested swapping cables between the powermac
> and the router.  I've done this with no effect.
> 
> I don't know how to make sense of things like tcpdump, but clearly
> something relatively simple is wrong with my setup, and I haven't been
> able to figure it out so far.  Any ideas about how to debug this
> problem are appreciated.  I've included some output from tcpdump and
> ifconfig below.
> 
> -russ
> 
> 
> [1] An email similar to this one was previously sent to the
> port-macppc list.  I reposted to netbsd-help in the hopes that more
> people read netbsd-help, and I'm doubtful that the problem is macppc
> specific.
> 
> 
> Here is the output if ifconfig:
> 
> /export/russe 2$ ifconfig  mc0
> ifconfig  mc0
> mc0: flags=8863<UP,BROADCAST,NOTRAILERS,RUNNING,SIMPLEX,MULTICAST> mtu 1500
>         address: 00:05:02:ce:73:66
>         media: Ethernet manual
>         inet 192.168.1.3 netmask 0xffffff00 broadcast 192.168.1.255
>         inet6 fe80::205:2ff:fece:7366%mc0 prefixlen 64 scopeid 0x1 
> 
> Here is some tcpdump output captured before and during an ftp
> transfer:
> 
> # /usr/sbin/tcpdump -n -i mc0 port ftp
> tcpdump: listening on mc0
> 18:59:03.211732 192.168.1.3.65430 > 204.152.184.75.21: S 150795642:150795642(0) win 16384 <mss 1460,nop,wscale 0,nop,nop,timestamp 664747 0>
> 18:59:03.304256 204.152.184.75.21 > 192.168.1.3.65430: S 1697308607:1697308607(0) ack 150795643 win 32768 <mss 1460,nop,wscale 0,nop,nop,timestamp 0 664747>
> 18:59:03.304426 192.168.1.3.65430 > 204.152.184.75.21: . ack 1 win 17520 <nop,nop,timestamp 664747 0>
> 18:59:03.405677 204.152.184.75.21 > 192.168.1.3.65430: P 1:62(61) ack 1 win 33580 <nop,nop,timestamp 0 0>
> 18:59:03.412502 192.168.1.3.65430 > 204.152.184.75.21: P 1:17(16) ack 62 win 17520 <nop,nop,timestamp 664748 0> [tos 0x10]
> 18:59:03.509096 204.152.184.75.21 > 192.168.1.3.65430: P 62:111(49) ack 17 win 33580 <nop,nop,timestamp 0 664748>
> 18:59:03.514799 192.168.1.3.65430 > 204.152.184.75.21: P 17:39(22) ack 111 win 17520 <nop,nop,timestamp 664748 0> [tos 0x10]
> 18:59:03.610659 204.152.184.75.21 > 192.168.1.3.65430: P 111:117(6) ack 39 win 33580 <nop,nop,timestamp 0 664748>
> 18:59:03.611993 204.152.184.75.21 > 192.168.1.3.65430: . 117:617(500) ack 39 win 33580 <nop,nop,timestamp 0 664748>
> 18:59:03.612191 192.168.1.3.65430 > 204.152.184.75.21: . ack 617 win 17020 <nop,nop,timestamp 664748 0> [tos 0x10]
> 18:59:03.613009 204.152.184.75.21 > 192.168.1.3.65430: . 1117:1617(500) ack 39 win 33580 <nop,nop,timestamp 0 664748>
> 18:59:03.613170 192.168.1.3.65430 > 204.152.184.75.21: . ack 617 win 17020 <nop,nop,timestamp 664748 0> [tos 0x10]
> 18:59:05.201876 204.152.184.75.21 > 192.168.1.3.65430: . 617:1117(500) ack 39 win 33580 <nop,nop,timestamp 4 664748>
> 18:59:05.202178 192.168.1.3.65430 > 204.152.184.75.21: . ack 1617 win 16520 <nop,nop,timestamp 664751 4> [tos 0x10]
> 18:59:05.297071 204.152.184.75.21 > 192.168.1.3.65430: . 1617:2117(500) ack 39 win 33580 <nop,nop,timestamp 4 664748>
> 18:59:05.400152 192.168.1.3.65430 > 204.152.184.75.21: . ack 2117 win 17520 <nop,nop,timestamp 664752 4> [tos 0x10]
> 18:59:05.494039 204.152.184.75.21 > 192.168.1.3.65430: P 2117:2301(184) ack 39 win 33580 <nop,nop,timestamp 4 664748>
> 18:59:05.600125 192.168.1.3.65430 > 204.152.184.75.21: . ack 2301 win 17520 <nop,nop,timestamp 664752 4> [tos 0x10]
> 18:59:05.661752 192.168.1.3.65430 > 204.152.184.75.21: P 39:45(6) ack 2301 win 17520 <nop,nop,timestamp 664752 4> [tos 0x10]
> 18:59:05.778995 204.152.184.75.21 > 192.168.1.3.65430: P 2301:2350(49) ack 45 win 33580 <nop,nop,timestamp 5 664752>
> 18:59:05.790645 192.168.1.3.65430 > 204.152.184.75.21: P 45:50(5) ack 2350 win 17520 <nop,nop,timestamp 664752 5> [tos 0x10]
> 18:59:05.883775 204.152.184.75.21 > 192.168.1.3.65430: P 2350:2385(35) ack 50 win 33580 <nop,nop,timestamp 5 664752>
> 18:59:05.884764 192.168.1.3.65430 > 204.152.184.75.21: P 50:58(8) ack 2385 win 17520 <nop,nop,timestamp 664753 5> [tos 0x10]
> 18:59:05.980672 204.152.184.75.21 > 192.168.1.3.65430: P 2385:2405(20) ack 58 win 33580 <nop,nop,timestamp 5 664753>
> 18:59:05.986607 192.168.1.3.65430 > 204.152.184.75.21: P 58:67(9) ack 2405 win 17520 <nop,nop,timestamp 664753 5> [tos 0x10]
> 18:59:06.078818 204.152.184.75.21 > 192.168.1.3.65430: P 2405:2434(29) ack 67 win 33580 <nop,nop,timestamp 5 664753>
> 18:59:06.084952 192.168.1.3.65430 > 204.152.184.75.21: P 67:72(5) ack 2434 win 17520 <nop,nop,timestamp 664753 5> [tos 0x10]
> 18:59:06.187074 204.152.184.75.21 > 192.168.1.3.65430: P 2434:2472(38) ack 72 win 33580 <nop,nop,timestamp 6 664753>
> 18:59:06.187685 192.168.1.3.65430 > 204.152.184.75.21: P 72:84(12) ack 2472 win 17520 <nop,nop,timestamp 664753 6> [tos 0x10]
> 18:59:06.284639 204.152.184.75.21 > 192.168.1.3.65430: P 2472:2478(6) ack 84 win 33580 <nop,nop,timestamp 6 664753>
> 18:59:06.285989 204.152.184.75.21 > 192.168.1.3.65430: . 2478:2978(500) ack 84 win 33580 <nop,nop,timestamp 6 664753>
> 18:59:06.286185 192.168.1.3.65430 > 204.152.184.75.21: . ack 2978 win 17020 <nop,nop,timestamp 664753 6> [tos 0x10]
> 18:59:06.286450 204.152.184.75.21 > 192.168.1.3.65430: . 2978:3478(500) ack 84 win 33580 <nop,nop,timestamp 6 664753>
> 18:59:06.400118 192.168.1.3.65430 > 204.152.184.75.21: . ack 3478 win 17520 <nop,nop,timestamp 664754 6> [tos 0x10]
> 18:59:06.492106 204.152.184.75.21 > 192.168.1.3.65430: P 3478:3524(46) ack 84 win 33580 <nop,nop,timestamp 6 664753>
> 18:59:06.600104 192.168.1.3.65430 > 204.152.184.75.21: . ack 3524 win 17474 <nop,nop,timestamp 664754 6> [tos 0x10]
> 18:59:06.638275 192.168.1.3.65430 > 204.152.184.75.21: P 84:89(5) ack 3524 win 17520 <nop,nop,timestamp 664754 6> [tos 0x10]
> 18:59:06.730774 204.152.184.75.21 > 192.168.1.3.65430: P 3524:3569(45) ack 89 win 33580 <nop,nop,timestamp 7 664754>
> 18:59:06.731607 192.168.1.3.65430 > 204.152.184.75.21: P 89:107(18) ack 3569 win 17520 <nop,nop,timestamp 664754 7> [tos 0x10]
> 18:59:06.823126 204.152.184.75.21 > 192.168.1.3.65430: P 3569:3575(6) ack 107 win 33580 <nop,nop,timestamp 7 664754>
> 18:59:07.000126 192.168.1.3.65430 > 204.152.184.75.21: . ack 3575 win 17520 <nop,nop,timestamp 664755 7> [tos 0x10]
> 18:59:07.092258 204.152.184.75.21 > 192.168.1.3.65430: P 3575:3713(138) ack 107 win 33580 <nop,nop,timestamp 7 664754>
> 18:59:07.109489 192.168.1.3.65430 > 204.152.184.75.21: P 107:112(5) ack 3713 win 17520 <nop,nop,timestamp 664755 7> [tos 0x10]
> 18:59:07.207819 204.152.184.75.21 > 192.168.1.3.65430: P 3713:3771(58) ack 112 win 33580 <nop,nop,timestamp 8 664755>
> 18:59:07.208561 192.168.1.3.65430 > 204.152.184.75.21: P 112:124(12) ack 3771 win 17520 <nop,nop,timestamp 664755 8> [tos 0x10]
> 18:59:07.329709 204.152.184.75.21 > 192.168.1.3.65430: P 3771:3800(29) ack 124 win 33580 <nop,nop,timestamp 8 664755>
> 18:59:07.335759 192.168.1.3.65430 > 204.152.184.75.21: P 124:129(5) ack 3800 win 17520 <nop,nop,timestamp 664756 8> [tos 0x10]
> 18:59:07.432091 204.152.184.75.21 > 192.168.1.3.65430: P 3800:3865(65) ack 129 win 33580 <nop,nop,timestamp 8 664756>
> 18:59:07.439256 192.168.1.3.65430 > 204.152.184.75.21: P 129:147(18) ack 3865 win 17520 <nop,nop,timestamp 664756 8> [tos 0x10]
> 18:59:07.531733 204.152.184.75.21 > 192.168.1.3.65430: P 3865:3877(12) ack 147 win 33580 <nop,nop,timestamp 8 664756>
> 18:59:07.532354 192.168.1.3.65430 > 204.152.184.75.21: P 147:153(6) ack 3877 win 17520 <nop,nop,timestamp 664756 8> [tos 0x10]
> 18:59:07.664693 204.152.184.75.21 > 192.168.1.3.65430: P 3877:3925(48) ack 153 win 33580 <nop,nop,timestamp 9 664756>
> 18:59:07.759828 192.168.1.3.65430 > 204.152.184.75.21: P 153:171(18) ack 3925 win 17520 <nop,nop,timestamp 664756 9> [tos 0x10]
> 18:59:08.033501 204.152.184.75.21 > 192.168.1.3.65430: P 3925:4000(75) ack 171 win 33580 <nop,nop,timestamp 9 664756>
> 18:59:08.200050 192.168.1.3.65430 > 204.152.184.75.21: . ack 4000 win 17520 <nop,nop,timestamp 664757 9> [tos 0x10]
> 18:59:49.500993 192.168.1.3.65430 > 204.152.184.75.21: P 171:174(3) ack 4000 win 17520 urg 3 <nop,nop,timestamp 664840 9> [tos 0x10]
> 18:59:49.501182 192.168.1.3.65430 > 204.152.184.75.21: P 174:181(7) ack 4000 win 17520 <nop,nop,timestamp 664840 9> [tos 0x10]
> 18:59:49.599260 204.152.184.75.21 > 192.168.1.3.65430: . ack 181 win 33573 <nop,nop,timestamp 92 664840>
> 18:59:49.599675 204.152.184.75.21 > 192.168.1.3.65430: P 4000:4042(42) ack 181 win 33580 <nop,nop,timestamp 92 664840>
> 18:59:49.610148 192.168.1.3.65430 > 204.152.184.75.21: . ack 4042 win 17520 <nop,nop,timestamp 664840 92> [tos 0x10]
> 18:59:49.701493 204.152.184.75.21 > 192.168.1.3.65430: P 4042:4072(30) ack 181 win 33580 <nop,nop,timestamp 93 664840>
> 18:59:49.810100 192.168.1.3.65430 > 204.152.184.75.21: . ack 4072 win 17490 <nop,nop,timestamp 664840 93> [tos 0x10]
> 18:59:49.840714 192.168.1.3.65430 > 204.152.184.75.21: P 181:187(6) ack 4072 win 17520 <nop,nop,timestamp 664841 93> [tos 0x10]
> 18:59:49.968958 204.152.184.75.21 > 192.168.1.3.65430: P 4072:4078(6) ack 187 win 33580 <nop,nop,timestamp 93 664841>
> 18:59:49.969890 204.152.184.75.21 > 192.168.1.3.65430: FP 4078:4267(189) ack 187 win 33580 <nop,nop,timestamp 93 664841>
> 18:59:49.970076 192.168.1.3.65430 > 204.152.184.75.21: . ack 4268 win 17331 <nop,nop,timestamp 664841 93> [tos 0x10]
> 18:59:50.147410 192.168.1.3.65430 > 204.152.184.75.21: F 187:187(0) ack 4268 win 17520 <nop,nop,timestamp 664841 93> [tos 0x10]
> 18:59:50.241631 204.152.184.75.21 > 192.168.1.3.65430: . ack 188 win 33580 <nop,nop,timestamp 94 664841>
> 
> 225 packets received by filter
> 0 packets dropped by kernel

--
The whole aim of practical politics is to keep the populace alarmed
[and hence clamorous to be led to safety] by menacing it with an
endless series of hobgoblins, all of them imaginary.  
             -- H.L. Mencken