WebVPN lets users establish a secure, remote-access VPN tunnel to a head-end
device using a web browser. Users are no longer restricted to a particular PC
or workstation, improving mobility and flexibility of access
. WebVPN is not a
replacement for IPSec, but widens application availability.
There is no
need for either a software or hardware client. WebVPN provides easy access to a
broad range of enterprise applications, including web resources, web enabled
applications, NT/Active Directory (AD) file shares that are web enabled,
e-mail, and other TCP-based applications from any computer connected to the
Internet that can reach HTTP(S) Internet sites.
WebVPN uses the SSL
protocol and its successor, TLS to provide a secure connection between remote
users and specific, supported internal resources at a central site.
WebVPN is currently available for VPN 3000 Series Concentrators, IOS Routers
running IOS version 12.3(14)T or later, and the Adaptive Security Appliance
5500 Series.
WebVPN Features
WebVPN features include the
following
:
- Secure access to internal web sites via HTTPS
- Windows File Access provides access to files on pre-configured file
servers, or file browsing on the network.
- Port Forwarding, or Application Access, for legacy application
support.
- E-mail Proxies enable e-mail via Post Office Protocol, Revision 3 (POP3S)
over SSL, Internet Messages Access Protocol, Revision 4 (IMAP4S) over SSL, and
Simple Mail Transfer Protocol Secure (SMTPS) over SSL proxies.
WebVPN is ideal for the following deployments:
- Unmanaged desktops
- Extranets
- Employee-owned computers
- Employees who only need occasional access
- Employees who need access to few applications
- Simple or locked-down access
- Restricted server and application access by population
WebVPN and IPSec comparison
Each type of remote access has
its own unique set of benefits. WebVPN allows clientless access, but there are
possible tradeoffs in ease of use and security. Many of these trade-offs can be
mitigated by properly implementing WebVPN. Note the following additional
characteristics of each solution shown in Figure
.