SNMP limit the output strings

Please HELP!

I configured SNMP on esxi 5.1

#esxcli system snmp set -c public

#esxcli system snmp set -t ip-addr/public

#esxcli system snmp set -e true

Sapwalk2.exe -i 192.168.0.1 -c public -v v1 -s 1.3.6.1.2.1 -t 2000 -r 1

sapwalker get result but only ~500 strings

after that i see the message "Device not responding"

i think that the output stops by anti ddos shield

if try

Sapwalk2.exe -i 192.168.0.1 -c public -v v1 -s 1.3.6.1.4.1 -t 2000 -r 1

all is fine

how to walk the entire tree?