[squid-users] Zero Sized Reply [attn: long post]

Hello,

We use squid 2.5-STABLE-3 (port 3128) to connect to the Internet via
traditional browser proxy configuration. Everything works great except for
specific sites (yahoo mail, aol mail, hotmail, and sometimes mapquest).
These sites return a "Zero Sized Reply" error message. Disabling squid
allows traffic through.

Was this problem ever addressed? HotMail fails with that message every
time. Sometimes mapquest works, but other times it fails as well.

I have looked at http://www.squid-cache.org/Doc/FAQ/FAQ-11.html#ss11.51 to
see if there is any information that can solve my "Zero Sized Reply"
problem. It looks like nobody knows what is going on, as it's full of
speculation. I have deleted cookies, disabled persitance connections, and
ensured that ECN is set to "0". Nothing. The problem is still here.

I think I have read every single post on "Zero Sized Reply" on google. Why
is this problem all over the place and why can't anybody figure it out?
It's a very common problem. Hopefully, someone here can spot what's wrong.
I really would appreciate solving this issue. I'd be happy do document and
post any additional information to the FAQ so that other people in the
future can fix their configurations.

Below is my squid.conf configuration:

acl all src 0.0.0.0/0.0.0.0
acl manager proto cache_object
acl localsrc src 127.0.0.1 10.0.0.0/255.0.0.0 192.0.0.0/255.0.0.0
198.140.0.0/255.255.0.0 66.0.0.0/255.0.0.0
acl localdst dst 127.0.0.1 10.0.0.0/255.0.0.0 192.0.0.0/255.0.0.0
198.140.0.0/255.255.0.0 66.0.0.0/255.0.0.0
acl SSL_ports port 443 563
acl Safe_ports port 80 21 443 563 70 210 1025-65535 980
acl CONNECT method CONNECT
acl webdav method PROPFIND TRACE PURGE PROPPATCH MKCOL COPY MOVE LOCK UNLOCK

append_domain .xxxxxx.org
cache_mgr admin@xxxxxx.org
ftp_user nobody@xxxxxx.org
http_access allow manager localsrc
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localsrc
http_access deny all

httpd_accel_host virtual
httpd_accel_with_proxy on
httpd_accel_uses_host_header on
icp_access allow all
miss_access allow all

redirect_program /usr/bin/squidguard -c /etc/squid/squidguard.conf
redirect_children 14

store_avg_object_size 3 KB

half_closed_clients off
server_persistent_connections off
client_persistent_connections off
cache_mem 20480 KB

uri_whitespace encode
pipeline_prefetch on

always_direct allow webdav
always_direct allow all

---
And a tcpdump of the communication between the squid server and hotmail:
16:24:58.731591 squid.xxxxxx.org.54018 > lc1.law5.hotmail.com.www: F
1681:1681(0) ack 3 win 5840 <nop,nop,timestamp 3
4258074 16290494> (DF)
16:24:58.731736 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: S
3050115030:3050115030(0) win 5840 <mss 1460,sack
OK,timestamp 34258074 0,nop,wscale 0> (DF)
16:24:58.731787 lc1.law5.hotmail.com.www > squid.xxxxxx.org.10438: .
694649172:694649184(12) ack 3057771393 win 4096
(DF)
16:24:58.731805 squid.xxxxxx.org.10438 > lc1.law5.hotmail.com.www: R
3057771393:3057771393(0) win 0 (DF)
16:24:58.811994 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.54019: S
1215809718:1215809718(0) ack 3050115031 win 1656
0 <mss 1380,nop,wscale 0,nop,nop,timestamp 0 0,nop,nop,sackOK>
16:24:58.812026 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: . ack 1
win 5840 <nop,nop,timestamp 34258082 0> (D
F)
16:24:58.812348 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: .
1:1369(1368) ack 1 win 5840 <nop,nop,timestamp 3
4258082 0> (DF)
16:24:58.812366 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: P
1369:1681(312) ack 1 win 5840 <nop,nop,timestamp
 34258082 0> (DF)
16:24:58.901436 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.54019: . ack
1369 win 16560 <nop,nop,timestamp 16304126 3
4258082>
16:24:59.067769 squid.xxxxxx.org.54018 > lc1.law5.hotmail.com.www: F
1681:1681(0) ack 3 win 5840 <nop,nop,timestamp 3
4258108 16290494> (DF)
16:24:59.068155 lc1.law5.hotmail.com.www > squid.xxxxxx.org.54018: R 3:3(0)
ack 1682 win 5840 <nop,nop,timestamp 3425
8108 16290494> (DF)
16:24:59.177767 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: P
1369:1681(312) ack 1 win 5840 <nop,nop,timestamp
 34258119 16304126> (DF)
16:24:59.259100 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.54019: . ack
1681 win 16248 <nop,nop,timestamp 16304129 3
4258119>
16:24:59.317909 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.54019: FP 1:2(1)
ack 1681 win 16248 <nop,nop,timestamp 16
304130 34258119>
16:24:59.318379 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: F
1681:1681(0) ack 3 win 5840 <nop,nop,timestamp 3
4258133 16304130> (DF)
16:24:59.318653 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.54019: F
560:560(0) ack 1681 win 16248 <nop,nop,timestamp
 16304130 34258119>
16:24:59.318922 lc2.bay0.hotmail.com.www > squid.xxxxxx.org.10440: .
1215809721:1215809733(12) ack 3050116712 win 409
6 (DF)
16:24:59.318948 squid.xxxxxx.org.10440 > lc2.bay0.hotmail.com.www: R
3050116712:3050116712(0) win 0 (DF)
16:24:59.597770 squid.xxxxxx.org.54019 > lc2.bay0.hotmail.com.www: F
1681:1681(0) ack 3 win 5840 <nop,nop,timestamp 3
4258161 16304130> (DF)
---
access.log
1070925890.474   8842 192.168.1.116 TCP_MISS/503 1353 GET
http://www.hotmail.msn.com/cgi-bin/sbox? - DIRECT/64.4.52.7 text/html
1070925899.318   7661 192.168.1.116 TCP_MISS/503 1353 GET
http://www.hotmail.msn.com/cgi-bin/sbox? - DIRECT/64.4.33.7 text/html
1070926116.643   7128 192.168.1.116 TCP_MISS/503 1353 GET
http://www.hotmail.msn.com/cgi-bin/sbox? - DIRECT/64.4.32.7 text/html
1070926136.891   7433 192.168.1.116 TCP_MISS/503 1353 GET
http://www.hotmail.msn.com/cgi-bin/sbox? - DIRECT/64.4.52.7 text/html
---
cache.log
2003/12/08 15:40:14| Starting Squid Cache version 2.5.STABLE3 for
i386-redhat-linux-gnu...
2003/12/08 15:40:14| Process ID 13137
2003/12/08 15:40:14| With 1024 file descriptors available
2003/12/08 15:40:14| DNS Socket created at 0.0.0.0, port 32805, FD 4
2003/12/08 15:40:14| Adding nameserver 127.0.0.1 from /etc/resolv.conf
2003/12/08 15:40:14| helperOpenServers: Starting 14 'squidguard' processes
2003/12/08 15:40:14| Unlinkd pipe opened on FD 23
2003/12/08 15:40:14| Swap maxSize 102400 KB, estimated 34133 objects
2003/12/08 15:40:14| Target number of buckets: 1706
2003/12/08 15:40:14| Using 8192 Store buckets
2003/12/08 15:40:14| Max Mem  size: 20480 KB
2003/12/08 15:40:14| Max Swap size: 102400 KB
2003/12/08 15:40:14| Rebuilding storage in /var/spool/squid (CLEAN)
2003/12/08 15:40:14| Using Least Load store dir selection
2003/12/08 15:40:14| Current Directory is /
2003/12/08 15:40:14| Loaded Icons.
2003/12/08 15:40:15| Accepting HTTP connections at 0.0.0.0, port 3128, FD
25.
2003/12/08 15:40:15| Accepting ICP messages at 0.0.0.0, port 3130, FD 26.
2003/12/08 15:40:15| WCCP Disabled.
2003/12/08 15:40:15| Ready to serve requests.
2003/12/08 15:40:15| Store rebuilding is 63.3% complete
2003/12/08 15:40:15| Done reading /var/spool/squid swaplog (6468 entries)
2003/12/08 15:40:15| Finished rebuilding storage from disk.
2003/12/08 15:40:15|      6468 Entries scanned
2003/12/08 15:40:15|         0 Invalid entries.
2003/12/08 15:40:15|         0 With invalid flags.
2003/12/08 15:40:15|      6468 Objects loaded.
2003/12/08 15:40:15|         0 Objects expired.
2003/12/08 15:40:15|         0 Objects cancelled.
2003/12/08 15:40:15|         0 Duplicate URLs purged.
2003/12/08 15:40:15|         0 Swapfile clashes avoided.
2003/12/08 15:40:15|   Took 0.4 seconds (16653.0 objects/sec).
2003/12/08 15:40:15| Beginning Validation Procedure
2003/12/08 15:40:15|   Completed Validation Procedure
2003/12/08 15:40:15|   Validated 6468 Entries
2003/12/08 15:40:15|   store_swap_size = 92148k
2003/12/08 15:40:15| storeLateRelease: released 0 objects
Regards,
Trevor.