Description:
------------
We are using an F5 BIGIP load balancer, and trying to monitor it. Running the test script results in "PHP Warning:  snmp2_real_walk(): No response from HOSTHERE in /home/tuc/Desktop/snmp2_real_walk.php on line 2" on CentOS and Windows 7, versions 5.3.3 through 5.6.12 . However :

[tuc@monitoring-01.sf ~]$ time snmpwalk -v2c -c PASSWORD  HOST .1.3.6.1.4.1.3375.2.2.10.2.3.1.1|wc -l
48

real	0m0.104s
user	0m0.037s
sys	0m0.006s

In every case I look a tcpdump returns well before the script bombs. 

The data returned (48 lines) includes some really long OIDS... :

SNMPv2-SMI::enterprises.3375.2.2.10.2.3.1.1.41.47.67.111.109.109.111.110.47.97.100.101.110.103.105.110.101.45.112.114.111.100.116.101.115.116.95.112.117.98.108.105.99.45.105.112.49.56.49.46.56.48 = STRING: "/Common/service1"
SNMPv2-SMI::enterprises.3375.2.2.10.2.3.1.1.42.47.67.111.109.109.111.110.47.97.100.101.110.103.105.110.101.45.112.114.111.100.116.101.115.116.95.112.117.98.108.105.99.45.105.112.49.56.49.46.52.52.51 = STRING: "/Common/service2"


Test script:
---------------
<?php
 print_r(snmp2_real_walk("HOSTHERE:161", "PASSWORDHERE", ".1.3.6.1.4.1.3375.2.2.10.2.3.1.1"));
?>

Expected result:
----------------
48 line array of OIDs and strings such as above

Actual result:
--------------
"PHP Warning:  snmp2_real_walk(): No response from HOSTHERE in /home/tuc/Desktop/snmp2_real_walk.php on line 2"