com asks about firewalls provided by the ISP.
The first step is to see exactly what security controls they offer and
decide if that's enough. It might not be.
An ISP based Internet security service should be able to prevent
inbound and outbound connections to services you don't want. They
might be able to block porn access and such. It makes sense for the
ISP to host a mail relay that provides your e-mail connectivity. Then
they're responsible for securing it against attack.
The ISP might also be able to restrict connections to authorized users
and/or workstations. To do this right these days they might support
one or more strong authentication techniques with tokens, one time
password generators, and such. If the ISP has an efficient service
organization they *might* provide prompt service for creating and
changing users' Internet access permissions.
However, the benefits to Web sites are going to be somewhat limited
unless your ISP also hosts your Internet Web servers. The most
interesting attacks these days are against servers, since they're
always visible to attackers. You still have to host your servers on a
strong host with mandatory protection if you're facing serious
threats. All the ISP will do is make sure that *only* HTTP connections
attack your HTTP server. That's a little help, but not that much.
An interesting side note, though, is that an ISP might be in a
position to "guarantee" the level of security being provided. They
have enough control over the traffic, the security configuration, and
the audit trail so that they could themselves verify the incident.
It's less appealing to guarantee security when a customer has full
custody of the security configuration and audit trail themselves.
com secure computing corporation