[squid-users] Tcp outgoing address

I want to change the outgoing src address of some users , exiting from my
squid box

I tried to configure tcp_outgoing_address option in squid.config as follows.

acl normal_service_net src 172.16.1.0/255.255.255.0
tcp_outgoing_address 172.16.1.3 normal_service_net

but I am unable to browse and getting this error in cache.log

2008/07/21 09:10:18| commBind: Cannot bind socket FD 15 to 172.16.1.3:0:
(99) Cannot assign requested address
2008/07/21 09:10:18| commBind: Cannot bind socket FD 15 to 172.16.1.3:0:
(99) Cannot assign requested address
2008/07/21 09:10:22| commBind: Cannot bind socket FD 15 to 172.16.1.3:0:
(99) Cannot assign requested address
2008/07/21 09:11:28| commBind: Cannot bind socket FD 15 to 172.16.1.3:0:
(99) Cannot assign requested address
Received on Mon Jul 21 2008 - 08:18:06 MDT