1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
<HTML>
<HEAD>
<TITLE>Apache module mod_proxy</TITLE>
</HEAD>
<!-- Background white, links blue (unvisited), navy (visited), red (active) -->
<BODY
BGCOLOR="#FFFFFF"
TEXT="#000000"
LINK="#0000FF"
VLINK="#000080"
ALINK="#FF0000"
>
<!--#include virtual="header.html" -->
<H1 ALIGN="CENTER">Apache module mod_proxy</H1>
This module is contained in the <CODE>mod_proxy.c</CODE> file for Apache 1.1.x,
or the <CODE>modules/proxy</CODE> subdirectory for Apache 1.2, and
is not compiled in by default. It provides for an <STRONG>HTTP
1.0</STRONG> caching proxy
server. It is only available in Apache 1.1 and later. Common configuration
questions are addressed <A HREF="#configs">after the directive
descriptions</A>.
<H3>Note:</H3>
<P>This module was experimental in Apache 1.1.x. As of Apache 1.2, mod_proxy
stability is <EM>greatly</EM> improved.<P>
<H2>Summary</H2>
This module implements a proxy/cache for Apache. It implements
proxying capability for
<CODE>FTP</CODE>,
<CODE>CONNECT</CODE> (for SSL),
<CODE>HTTP/0.9</CODE>, and
<CODE>HTTP/1.0</CODE>.
The module can be configured to connect to other proxy modules for these
and other protocols.
<H2>Directives</H2>
<UL>
<LI><A HREF="#proxyrequests">ProxyRequests</A>
<LI><A HREF="#proxyremote">ProxyRemote</A>
<LI><A HREF="#proxypass">ProxyPass</A>
<LI><A HREF="#proxypassreverse">ProxyPassReverse</A>
<LI><A HREF="#proxyblock">ProxyBlock</A>
<LI><A HREF="#allowconnect">AllowCONNECT</A>
<LI><A HREF="#proxyreceivebuffersize">ProxyReceiveBufferSize</A>
<LI><A HREF="#noproxy">NoProxy</A>
<LI><A HREF="#proxydomain">ProxyDomain</A>
<LI><A HREF="#proxyvia">ProxyVia</A>
<LI><A HREF="#cacheroot">CacheRoot</A>
<LI><A HREF="#cachesize">CacheSize</A>
<LI><A HREF="#cachemaxexpire">CacheMaxExpire</A>
<LI><A HREF="#cachedefaultexpire">CacheDefaultExpire</A>
<LI><A HREF="#cachelastmodifiedfactor">CacheLastModifiedFactor</A>
<LI><A HREF="#cachegcinterval">CacheGcInterval</A>
<LI><A HREF="#cachedirlevels">CacheDirLevels</A>
<LI><A HREF="#cachedirlength">CacheDirLength</A>
<LI><A HREF="#cacheforcecompletion">CacheForceCompletion</A>
<LI><A HREF="#nocache">NoCache</A>
</UL>
<HR>
<H2><A NAME="proxyrequests">ProxyRequests</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyRequests <EM>on/off</EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>ProxyRequests Off</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyRequests is only available in
Apache 1.1 and later.<P>
This allows or prevents Apache from functioning as a proxy
server. Setting ProxyRequests to 'off' does not disable use of the <A
HREF="#proxypass">ProxyPass</A> directive.
<HR>
<H2><A NAME="proxyremote">ProxyRemote</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyRemote <EM><match> <remote-server></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyRemote is only available in
Apache 1.1 and later.<P>
This defines remote proxies to this proxy. <match> is either the
name of a URL-scheme that the remote server supports, or a partial URL
for which the remote server should be used, or '*' to indicate the
server should be contacted for all requests. <remote-server> is a
partial URL for the remote server. Syntax:
<PRE>
<remote-server> = <protocol>://<hostname>[:port]
</PRE>
<protocol> is the protocol that should be used to communicate
with the remote server; only "http" is supported by this module.
<P>
Example:
<PRE>
ProxyRemote http://goodguys.com/ http://mirrorguys.com:8000
ProxyRemote * http://cleversite.com
ProxyRemote ftp http://ftpproxy.mydomain.com:8080
</PRE>
In the last example, the proxy will forward FTP requests, encapsulated
as yet another HTTP proxy request, to another proxy which can handle
them.
<HR>
<H2><A NAME="proxypass">ProxyPass</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyPass <EM><path> <url></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyPass is only available in
Apache 1.1 and later.<P>
This directive allows remote servers to be mapped into the space of the local
server; the local server does not act as a proxy in the conventional sense,
but appears to be a mirror of the remote server. <path> is the name of
a local virtual path; <url> is a partial URL for the remote server.
<P>
Suppose the local server has address <SAMP>http://wibble.org/</SAMP>; then
<PRE>
ProxyPass /mirror/foo/ http://foo.com/
</PRE>
will cause a local request for the
<<SAMP>http://wibble.org/mirror/foo/bar</SAMP>> to be
internally converted into a proxy request to
<<SAMP>http://foo.com/bar</SAMP>>.
<HR>
<H2><A NAME="proxypassreverse">ProxyPassReverse</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyPassReverse <EM><path> <url></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyPassReverse is only available in
Apache 1.3b6 and later.<P>
This directive lets Apache adjust the URL in the <TT>Location</TT> header on
HTTP redirect responses. For instance this is essential when Apache is used as
a reverse proxy to avoid by-passing the reverse proxy because of HTTP
redirects on the backend servers which stay behind the reverse proxy.
<P>
<path> is the name of a local virtual path.<BR>
<url> is a partial URL for the remote server - the same way they are
used for the <TT>ProxyPass</TT> directive.
<P>
Example:<BR>
Suppose the local server has address <SAMP>http://wibble.org/</SAMP>; then
<PRE>
ProxyPass /mirror/foo/ http://foo.com/
ProxyPassReverse /mirror/foo/ http://foo.com/
</PRE>
will not only cause a local request for the
<<SAMP>http://wibble.org/mirror/foo/bar</SAMP>> to be internally
converted into a proxy request to <<SAMP>http://foo.com/bar</SAMP>> (the
functionality <SAMP>ProxyPass</SAMP> provides here). It also takes care of
redirects the server foo.com sends: when <SAMP>http://foo.com/bar</SAMP> is
redirected by him to <SAMP>http://foo.com/quux</SAMP> Apache adjusts this to
<SAMP>http://wibble.org/mirror/foo/quux</SAMP> before forwarding the HTTP
redirect response to the client.
<P>
Note that this <SAMP>ProxyPassReverse</SAMP> directive can also be used in
conjunction with the proxy pass-through feature ("<SAMP>RewriteRule ...
[P]</SAMP>") from
<A
HREF="mod_rewrite.html#RewriteRule"
><TT>mod_rewrite</TT></A> because its doesn't depend on a corresponding
<SAMP>ProxyPass</SAMP> directive.
<HR>
<H2><A NAME="allowconnect">AllowCONNECT</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> AllowCONNECT <EM><port list></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM><SAMP>AllowCONNECT</SAMP> 443 563</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> <SAMP>AllowCONNECT</SAMP> is only
available in Apache 1.3.2 and later.<P>
The <SAMP>AllowCONNECT</SAMP> directive specifies a list of port numbers
to which the proxy <SAMP>CONNECT</SAMP> method may connect.
Today's browsers use this method when a <EM>https</EM> connection
is requested and proxy tunneling over <EM>http</EM> is in effect.<BR>
By default, only the default https port (443) and the default
snews port (563) are enabled. Use the <SAMP>AllowCONNECT</SAMP>
directive to overrride this default and allow connections to the
listed ports only.
<HR>
<H2><A NAME="proxyblock">ProxyBlock</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyBlock <EM><word/host/domain list></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyBlock is only available in
Apache 1.2 and later.<P>
The ProxyBlock directive specifies a list of words, hosts and/or domains,
separated by spaces. HTTP, HTTPS, and FTP document requests to matched words,
hosts or domains are <EM>blocked</EM> by the proxy server. The proxy module
will also attempt to determine IP addresses of list items which may be
hostnames during startup, and cache them for match test as well. Example:
<PRE>
ProxyBlock joes-garage.com some-host.co.uk rocky.wotsamattau.edu
</PRE>
'rocky.wotsamattau.edu' would also be matched if referenced by IP address.<P>
Note that 'wotsamattau' would also be sufficient to match 'wotsamattau.edu'.<P>
Note also that
<PRE>
ProxyBlock *
</PRE>
blocks connections to all sites.
<HR>
<H2><A NAME="proxyreceivebuffersize">ProxyReceiveBufferSize</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyReceiveBufferSize <EM><bytes></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyReceiveBufferSize is only available in
Apache 1.3 and later.<P>
The ProxyReceiveBufferSize directive specifies an explicit network buffer size
for outgoing HTTP and FTP connections, for increased throughput. It has to be
greater than 512 or set to 0 to indicate that the system's default buffer size
should be used.
<P>
Example:
<PRE>
ProxyReceiveBufferSize 2048
</PRE>
<HR>
<H2><A NAME="noproxy">NoProxy</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> NoProxy { <A HREF="#domain"><EM><Domain></EM></A>
| <A HREF="#subnet"><EM><SubNet></EM></A>
| <A HREF="#ipaddr"><EM><IpAddr></EM></A>
| <A HREF="#hostname"><EM><Hostname></EM></A>
} <BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> NoProxy is only available in
Apache 1.3 and later.<P>
This directive is only useful for Apache proxy servers within intranets.
The NoProxy directive specifies a list of subnets, IP addresses, hosts
and/or domains, separated by spaces. A request to a host which matches
one or more of these is always served directly, without forwarding to
the configured ProxyRemote proxy server(s).
<P>
Example:
<PRE>
ProxyRemote * http://firewall.mycompany.com:81
NoProxy .mycompany.com 192.168.112.0/21
</PRE>
The arguments to the NoProxy directive are one of the following type list:
<DL>
<!-- ===================== Domain ======================= -->
<A NAME="domain">
<DT><EM>Domain</EM></A>
<DD>A <EM>Domain</EM> is a partially qualified DNS domain name, preceded
by a period.
It represents a list of hosts which logically belong to the same DNS
domain or zone (<EM>i.e.</EM>, the suffixes of the hostnames are all ending in
<EM>Domain</EM>).<BR>
Examples: <SAMP>.com</SAMP> <SAMP>.apache.org.</SAMP><BR>
To distinguish <EM>Domain</EM>s from <A HREF="#hostname"><EM>Hostname</EM></A>s (both
syntactically and semantically; a DNS domain can have a DNS A record,
too!), <EM>Domain</EM>s are always written
with a leading period.<BR>
Note: Domain name comparisons are done without regard to the case,
and <EM>Domain</EM>s are always assumed to be anchored in the root
of the DNS tree, therefore two domains <SAMP>.MyDomain.com</SAMP> and
<SAMP>.mydomain.com.</SAMP> (note the trailing period) are
considered equal. Since a domain comparison does not involve a DNS
lookup, it is much more efficient than subnet comparison.
<!-- ===================== SubNet ======================= -->
<A NAME="subnet">
<DT><EM>SubNet</EM></A>
<DD>A <EM>SubNet</EM> is a partially qualified internet address in
numeric (dotted quad) form, optionally followed by a slash and the
netmask, specified as the number of significant bits in the
<EM>SubNet</EM>. It is used to represent a subnet of hosts which can
be reached over a common network interface. In the absence of the
explicit net mask it is assumed that omitted (or zero valued)
trailing digits specify the mask. (In this case, the netmask can
only be multiples of 8 bits wide.)<BR>
Examples:
<DL>
<DT><SAMP>192.168</SAMP> or <SAMP>192.168.0.0</SAMP>
<DD>the subnet 192.168.0.0 with an implied netmask of 16 valid bits
(sometimes used in the netmask form <SAMP>255.255.0.0</SAMP>)
<DT><SAMP>192.168.112.0/21</SAMP>
<DD>the subnet <SAMP>192.168.112.0/21</SAMP> with a netmask of 21
valid bits (also used in the form 255.255.248.0)
</DL>
As a degenerate case, a <EM>SubNet</EM> with 32 valid bits is the
equivalent to an <EM>IPAddr</EM>, while a <EM>SubNet</EM> with zero
valid bits (<EM>e.g.</EM>, 0.0.0.0/0) is the same as the constant
<EM>_Default_</EM>, matching any IP address.
<!-- ===================== IPAddr ======================= -->
<A NAME="ipaddr">
<DT><EM>IPAddr</EM></A>
<DD>A <EM>IPAddr</EM> represents a fully qualified internet address in
numeric (dotted quad) form. Usually, this address represents a
host, but there need not necessarily be a DNS domain name
connected with the address.<BR>
Example: 192.168.123.7<BR>
Note: An <EM>IPAddr</EM> does not need to be resolved by the DNS
system, so it can result in more effective apache performance.
<P><STRONG>See Also:</STRONG>
<A HREF="../dns-caveats.html">DNS Issues</A></P>
<!-- ===================== Hostname ======================= -->
<A NAME="hostname">
<DT><EM>Hostname</EM></A>
<DD>A <EM>Hostname</EM> is a fully qualified DNS domain name which can
be resolved to one or more <A
HREF="#ipaddr"><EM>IPAddrs</EM></A> via the DNS domain name service.
It represents a logical host (in contrast to
<A HREF="#domain"><EM>Domain</EM></A>s, see
above) and must be resolvable to at least one <A
HREF="#ipaddr"><EM>IPAddr</EM></A> (or often to a list of hosts
with different <A HREF="#ipaddr"><EM>IPAddr</EM></A>'s).<BR>
Examples: <SAMP>prep.ai.mit.edu</SAMP>
<SAMP>www.apache.org.</SAMP><BR>
Note: In many situations, it is more effective to specify an
<A HREF="#ipaddr"><EM>IPAddr</EM></A> in place of a
<EM>Hostname</EM> since a DNS lookup
can be avoided. Name resolution in Apache can take a remarkable deal
of time when the connection to the name server uses a slow PPP
link.<BR>
Note: <EM>Hostname</EM> comparisons are done without regard to the case,
and <EM>Hostname</EM>s are always assumed to be anchored in the root
of the DNS tree, therefore two hosts <SAMP>WWW.MyDomain.com</SAMP>
and <SAMP>www.mydomain.com.</SAMP> (note the trailing period) are
considered equal.<BR>
<P><STRONG>See Also:</STRONG>
<A HREF="../dns-caveats.html">DNS Issues</A></P>
</DL>
<HR>
<H2><A NAME="proxydomain">ProxyDomain</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyDomain <EM><Domain></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyDomain is only available in
Apache 1.3 and later.<P>
This directive is only useful for Apache proxy servers within intranets.
The ProxyDomain directive specifies the default domain which the apache
proxy server will belong to. If a request to a host without a domain name
is encountered, a redirection response to the same host
with the configured <EM>Domain</EM> appended will be generated.
<P>
Example:
<PRE>
ProxyRemote * http://firewall.mycompany.com:81
NoProxy .mycompany.com 192.168.112.0/21
ProxyDomain .mycompany.com
</PRE>
<HR>
<H2><A NAME="proxyvia">ProxyVia</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> ProxyVia { <EM>off</EM>
| <EM>on</EM>
| <EM>full</EM>
| <EM>block</EM>
}<BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>ProxyVia off</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> ProxyVia is only available in
Apache 1.3.2 and later.<P>
This directive controls the use of the <SAMP>Via:</SAMP> HTTP header
by the proxy. Its intended use is to control the flow of of proxy
requests along a chain of proxy servers.
See RFC2068 (HTTP/1.1) for an explanation of <SAMP>Via:</SAMP> header lines.<UL>
<LI>If set to <EM>off</EM>, which is the default, no special
processing is performed. If a request or reply contains a <SAMP>Via:</SAMP> header,
it is passed through unchanged.
<LI>If set to <EM>on</EM>, each request and reply will get a <SAMP>Via:</SAMP> header
line added for the current host.
<LI>If set to <EM>full</EM>, each generated <SAMP>Via:</SAMP> header line will
additionally have the Apache server version shown as a <SAMP>Via:</SAMP> comment field.
<LI>If set to <EM>block</EM>, every proxy request will have all its
<SAMP>Via:</SAMP> header lines removed. No new <SAMP>Via:</SAMP> header will be generated.
</UL>
<HR>
<H2><A NAME="cacheforcecompletion">CacheForceCompletion</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheForceCompletion <EM><percentage></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>90</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheForceCompletion is only available in
Apache 1.3.1 and later.<P>
If an http transfer that is being cached is cancelled, the proxy module will
complete the transfer to cache if more than the percentage specified has
already been transferred.<P>
This is a percentage, and must be a number between 1 and 100, or 0 to use
the default. 100 will cause a document to be cached only if the transfer
was allowed to complete. A number between 60 and 90 is recommended.
<HR>
<H2><A NAME="cacheroot">CacheRoot</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheRoot <EM><directory></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheRoot is only available in
Apache 1.1 and later.<P>
Sets the name of the directory to contain cache files; this must be
writable by the httpd server.
(see the <A HREF="core.html#user"><CODE>User</CODE></A> directive).<BR>
Setting <CODE>CacheRoot</CODE> enables proxy cacheing; without defining
a <CODE>CacheRoot</CODE>, proxy functionality will be available
if <CODE>ProxyRequests</CODE> are set to <CODE>On</CODE>, but no
cacheing will be available.
<HR>
<H2><A NAME="cachesize">CacheSize</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheSize <EM><size></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheSize 5</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheSize is only available in
Apache 1.1 and later.<P>
Sets the desired space usage of the cache, in KB (1024-byte units). Although
usage may grow above this setting, the garbage collection will delete files
until the usage is at or below this setting.<BR>
Depending on the expected proxy traffic volume and <CODE>CacheGcInterval</CODE>,
use a value which is at least 20 to 40 % lower than the available space.
<HR>
<H2><A NAME="cachegcinterval">CacheGcInterval</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheGcInterval <EM><time></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheGcinterval is only available in
Apache 1.1 and later.<P>
Check the cache every <time> hours, and delete files if the space
usage is greater than that set by CacheSize. Note that <time> accepts a
float value, you could for example use <CODE>CacheGcInterval 1.5</CODE> to
check the cache every 90 minutes. (If unset, no garbage collection will
be performed, and the cache will grow indefinitely.)
Note also that the larger the <CODE>CacheGcInterval</CODE>, the more
extra space beyond the configured <CODE>CacheSize</CODE> will be
needed for the cache between garbage collections.<BR> <!--
Note that due to a design flaw, Apache does not automatically force a
garbage collection when the available space on the file system where
the cache resides is exhausted. -->
<HR>
<H2><A NAME="cachemaxexpire">CacheMaxExpire</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheMaxExpire <EM><time></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheMaxExpire 24</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheMaxExpire is only available in
Apache 1.1 and later.<P>
Cachable HTTP documents will be retained for at most <time> hours without
checking the origin server. Thus documents can be at most <time>
hours out of date. This restriction is enforced even if an expiry date
was supplied with the document.
<HR>
<H2><A NAME="cachelastmodifiedfactor">CacheLastModifiedFactor</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheLastModifiedFactor <EM><factor></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheLastModifiedFactor 0.1</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheLastModifiedFactor is only available in
Apache 1.1 and later.<P>
If the origin HTTP server did not supply an expiry date for the
document, then estimate one using the formula
<PRE>
expiry-period = time-since-last-modification * <factor>
</PRE>
For example, if the document was last modified 10 hours ago, and
<factor> is 0.1, then the expiry period will be set to 10*0.1 = 1 hour.
<P>If the expiry-period would be longer than that set by CacheMaxExpire,
then the latter takes precedence.
<HR>
<H2><A NAME="cachedirlevels">CacheDirLevels</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheDirLevels <EM><levels></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheDirLevels 3</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheDirLevels is only available in
Apache 1.1 and later.<P>
CacheDirLevels sets the number of levels of subdirectories in the cache.
Cached data will be saved this many directory levels below CacheRoot.
<HR>
<H2><A NAME="cachedirlength">CacheDirLength</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheDirLength <EM><length></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheDirLength 1</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheDirLength is only available in
Apache 1.1 and later.<P>
CacheDirLength sets the number of characters in proxy cache subdirectory names.
<HR>
<H2><A NAME="cachedefaultexpire">CacheDefaultExpire</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> CacheDefaultExpire <EM><time></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <CODE>CacheDefaultExpire 1</CODE><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> CacheDefaultExpire is only available in
Apache 1.1 and later.<P>
If the document is fetched via a protocol that does not support expiry times,
then use <time> hours as the expiry time.
<A HREF="#cachemaxexpire">CacheMaxExpire</A> does <STRONG>not</STRONG>
override this setting.
<HR>
<H2><A NAME="nocache">NoCache</A></H2>
<A
HREF="directive-dict.html#Syntax"
REL="Help"
><STRONG>Syntax:</STRONG></A> NoCache <EM><word/host/domain list></EM><BR>
<A
HREF="directive-dict.html#Default"
REL="Help"
><STRONG>Default:</STRONG></A> <EM>None</EM><BR>
<A
HREF="directive-dict.html#Context"
REL="Help"
><STRONG>Context:</STRONG></A> server config, virtual host<BR>
<A
HREF="directive-dict.html#Override"
REL="Help"
><STRONG>Override:</STRONG></A> <EM>Not applicable</EM><BR>
<A
HREF="directive-dict.html#Status"
REL="Help"
><STRONG>Status:</STRONG></A> Base<BR>
<A
HREF="directive-dict.html#Module"
REL="Help"
><STRONG>Module:</STRONG></A> mod_proxy<BR>
<A
HREF="directive-dict.html#Compatibility"
REL="Help"
><STRONG>Compatibility:</STRONG></A> NoCache is only available in
Apache 1.1 and later.<P>
The NoCache directive specifies a list of words, hosts and/or domains, separated
by spaces. HTTP and non-passworded FTP documents from matched words, hosts or
domains are <EM>not</EM> cached by the proxy server. The proxy module will
also attempt to determine IP addresses of list items which may be hostnames
during startup, and cache them for match test as well. Example:
<PRE>
NoCache joes-garage.com some-host.co.uk bullwinkle.wotsamattau.edu
</PRE>
'bullwinkle.wotsamattau.edu' would also be matched if referenced by IP
address.<P>
Note that 'wotsamattau' would also be sufficient to match 'wotsamattau.edu'.<P>
Note also that
<PRE>
NoCache *
</PRE>
disables caching completely.<P>
<HR>
<H2><A NAME="configs">Common configuration topics</A></H2>
<UL>
<LI><A HREF="#access">Controlling access to your proxy</A>
<LI><A HREF="#shortname">Using Netscape hostname shortcuts</A>
<LI><A HREF="#mimetypes">Why doesn't file type <EM>xxx</EM> download via FTP?</A>
<LI><A HREF="#startup">Why does Apache start more slowly when using the
proxy module?</A>
<LI><A HREF="#socks">Can I use the Apache proxy module with my SOCKS proxy?</A>
<LI><A HREF="#intranet">What other functions are useful for an intranet proxy server?</A>
</UL>
<H2><A NAME="access">Controlling access to your proxy</A></H2>
You can control who can access your proxy via the normal <Directory>
control block using the following example:<P>
<PRE>
<Directory proxy:*>
order deny,allow
deny from [machines you'd like *not* to allow by IP address or name]
allow from [machines you'd like to allow by IP address or name]
</Directory>
</PRE><P>
A <Files> block will also work, and is the only method known to work
for all possible URLs in Apache versions earlier than 1.2b10.<P>
<H2><A NAME="shortname">Using Netscape hostname shortcuts</A></H2>
There is an optional patch to the proxy module to allow Netscape-like
hostname shortcuts to be used. It's available from the
<A HREF="http://www.apache.org/dist/contrib/patches/1.2/netscapehost.patch"
><SAMP>contrib/patches/1.2</SAMP></A> directory on the Apache Web site.<P>
<H2><A NAME="mimetypes">Why doesn't file type <EM>xxx</EM> download via FTP?</A></H2>
You probably don't have that particular file type defined as
<EM>application/octet-stream</EM> in your proxy's mime.types configuration
file. A useful line can be<P>
<PRE>
application/octet-stream bin dms lha lzh exe class tgz taz
</PRE>
<H2><A NAME="type">How can I force an FTP ASCII download of File <EM>xxx</EM>?</A></H2>
In the rare situation where you must download a specific file using the FTP
<STRONG>ASCII</STRONG> transfer method (while the default transfer is in
<STRONG>binary</STRONG> mode), you can override mod_proxy's default by
suffixing the request with <SAMP>;type=a</SAMP> to force an ASCII transfer.<P>
<H2><A NAME="startup">Why does Apache start more slowly when using the
proxy module?</A></H2>
If you're using the <CODE>ProxyBlock</CODE> or <CODE>NoCache</CODE>
directives, hostnames' IP addresses are looked up and cached during
startup for later match test. This may take a few seconds (or more)
depending on the speed with which the hostname lookups occur.<P>
<H2><A NAME="socks">Can I use the Apache proxy module with my SOCKS proxy?</A></H2>
Yes. Just build Apache with the rule <CODE>SOCKS4=yes</CODE> in your
<EM>Configuration</EM> file, and follow the instructions there. SOCKS5
capability can be added in a similar way (there's no <CODE>SOCKS5</CODE>
rule yet), so use the <CODE>EXTRA_LDFLAGS</CODE> definition, or build Apache
normally and run it with the <EM>runsocks</EM> wrapper provided with SOCKS5,
if your OS supports dynamically linked libraries.<P>
Some users have reported problems when using SOCKS version 4.2 on Solaris.
The problem was solved by upgrading to SOCKS 4.3.<P>
Remember that you'll also have to grant access to your Apache proxy machine by
permitting connections on the appropriate ports in your SOCKS daemon's
configuration.<P>
<H2><A NAME="intranet">What other functions are useful for an intranet proxy server?</A></H2>
<P>An Apache proxy server situated in an intranet needs to forward external
requests through the company's firewall. However, when it has to access
resources within the intranet, it can bypass the firewall when accessing
hosts. The <A HREF="#noproxy">NoProxy</A> directive is useful for specifying
which hosts belong to the intranet and should be accessed directly.</P>
<P>Users within an intranet tend to omit the local domain name from their
WWW requests, thus requesting "http://somehost/" instead of
"http://somehost.my.dom.ain/". Some commercial proxy servers let them get
away with this and simply serve the request, implying a configured
local domain. When the <A HREF="#proxydomain">ProxyDomain</A> directive
is used and the server is <A HREF="#proxyrequests">configured for
proxy service</A>, Apache can return a redirect response and send the client
to the correct, fully qualified, server address. This is the preferred method
since the user's bookmark files will then contain fully qualified hosts.</P>
<!--#include virtual="footer.html" -->
</BODY>
</HTML>
|
