How to Block/Deny, Proxy on Cisco Router?

[mohamednselim]

Dear all,

Please I need to know hot to block or deny a proxy softwares from Cisco router.

Explaning: I have a network running and I have a proxy server (Microsoft) which the users cant get to the interent without the proxy setting on there pc's, All of them in the domain of the company. but some users use a proxy software and by pass the proxy server to open the non-authorized websites fromt he server.

I need to block them from my cisco router as my router is the end point of the company and I have my access lists there which allow users to go to the internet with or without proxy.

For example on the accesslist: I have 2 vlans, say vlan 1 connect on the internet directly wihtout using the proxy server, vlan 2 cant connect to the internet unless they have the proxy setting. but som users from vlan 2 use proxy softwares which on the report of microsoft says there is anonymus peopel opening this and this websites so they are using the bypassing proxy softwares but I need to block or deny it from my router for not getting outside the network without the proxy and not bypassing it.

I hope I explained the problem clearly.

I need som help please.

Thanks all,

Regards,

Mohamed Selim.

[Chris Illsley]

Hi,

With the setup you describe your ACLs should be blocking direct aceess to the proxy sites, what appears to be happening is that the users are accessing the proxy sites via the proxy server.

Not knowing what type of web proxy you are running it's hard to say what the fix is.

Thanks

Chris

[mohamednselim]

Dear Chris,

The proxy server is TMG from Microsoft. Yes the ACLs block direct accessto unwanted sites.

Some users bypassing the TMG proxy server with the proxy applications like (Ultrasurf, FreeGate, Hotspot Shield...etc)

I need to block the softwares from the router so they cant connect to it.

Thanks,

Mohamed Selim.