Re: Diagnose co-location networking problem

Ok, this is a little unfortunate: I can't run traceroute from the client PC (the service provider doesn't seem to like it). (Nor can I use ping)

The server FreeBSD kernel doesn't support tcpdump. I should recompile it then, but not now.

So I ran the netstat tests, seeing no other suggestion. Below is the output before and after "failed" accesses. If I understand, there seems no indication of lost packets.

At least the problem is rather reproducible: run 'lynx -dump http://stbgo.org > /dev/null' in a loop, 15 times and a failure occurs. I also thought maybe the ssh session might be interfering, rather than showing a live connection; but without it the same occurs.

Thanks a lot to all for now.

Stephan

# Both on client and server:
$ netstat -i > /tmp/before
$ netstat -s | grep -i ret >> /tmp/before
... run test .... recognize failure ...
$ netstat -i > /tmp/after
$ netstat -s | grep -i ret >> /tmp/after

Client first.

$ cat /tmp/before
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 012471498 0 0 0 8604916 36 0 1 BMRU
eth0: 1500 0 - no statistics available - BMRU
eth0: 1500 0 - no statistics available - BMRU
lo 16436 0 429696 0 0 0 429696 0 0 0 LRU
66656 segments retransmited
TCPLostRetransmit: 0
TCPFastRetrans: 1233
TCPForwardRetrans: 18
TCPSlowStartRetrans: 476
$ cat /tmp/after
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 012471903 0 0 0 8605107 36 0 1 BMRU
eth0: 1500 0 - no statistics available - BMRU
eth0: 1500 0 - no statistics available - BMRU
lo 16436 0 429786 0 0 0 429786 0 0 0 LRU
66665 segments retransmited
TCPLostRetransmit: 0
TCPFastRetrans: 1233
TCPForwardRetrans: 18
TCPSlowStartRetrans: 476

Now server
$ cat /tmp/before_server
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
bge0 1500 <Link#1> 00:0b:cd:4e:40:00 156342 3 146739 0 599 bge0 1500 65.110.18.136 df1 144448 - 145988 - - bge1* 1500 <Link#2> 00:0b:cd:4e:41:11 0 0 0 0 0 pflog 33208 <Link#3> 0 0 0 0 0 lo0 16384 <Link#4> 34545 0 34545 0 0 lo0 16384 your-net localhost.stephan 34454 - 34454 - - pfsyn 2020 <Link#5> 0 0 0 0 0 565 data packets (372083 bytes) retransmitted
38 data packets unnecessarily retransmitted
540 retransmit timeouts
156 retransmitted
0 invalid return addresses
0 no return routes
$ cat /tmp/after_server
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
bge0 1500 <Link#1> 00:0b:cd:4e:40:00 156579 3 146957 0 599 bge0 1500 65.110.18.136 df1 144671 - 146206 - - bge1* 1500 <Link#2> 00:0b:cd:4e:41:11 0 0 0 0 0 pflog 33208 <Link#3> 0 0 0 0 0 lo0 16384 <Link#4> 34685 0 34685 0 0 lo0 16384 your-net localhost.stephan 34594 - 34594 - - pfsyn 2020 <Link#5> 0 0 0 0 0 565 data packets (372083 bytes) retransmitted
38 data packets unnecessarily retransmitted
540 retransmit timeouts
156 retransmitted
0 invalid return addresses
0 no return routes
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