A few things to test:
- can you try disabling the firewall any seeing if that works?
- enable web sharing and test localhost/ (make sure it works in a browser first)
If neither of those work can you open a terminal and
$ sudo opensnoop
then run the apache bench and post the output of the opensnoop terminal in the question. If none of that works you could try installing macports and then installing apache from there and seeing if that works as a work around(sort of lame).
My Air is on lion but the apache version is different(there was an update recently, have you already installed that?). I was able to verify ab does work for me:
$ ab -V
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
$ uname -a
Darwin air.local 11.1.0 Darwin Kernel Version 11.1.0: Tue Jul 26 16:07:11 PDT 2011; root:xnu-1699.22.81~1/RELEASE_X86_64 x86_64
$ ab google.com/
This is ApacheBench, Version 2.3 <$Revision: 655654 $>
Copyright 1996 Adam Twiss, Zeus Technology Ltd, http://www.zeustech.net/
Licensed to The Apache Software Foundation, http://www.apache.org/
Benchmarking google.com (be patient).....done
Server Software: gws
Server Hostname: google.com
Server Port: 80
Document Path: /
Document Length: 219 bytes
Concurrency Level: 1
Time taken for tests: 4.130 seconds
Complete requests: 1
Failed requests: 0
Write errors: 0
Non-2xx responses: 1
Total transferred: 511 bytes
HTML transferred: 219 bytes
Requests per second: 0.24 [#/sec] (mean)
Time per request: 4130.343 [ms] (mean)
Time per request: 4130.343 [ms] (mean, across all concurrent requests)
Transfer rate: 0.12 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 4119 4119 0.0 4119 4119
Processing: 11 11 0.0 11 11
Waiting: 11 11 0.0 11 11
Total: 4130 4130 0.0 4130 4130