MS is doing something very Jerico'ish with "DirectAccess" ... very loosely, "Automagic IPsec + IPv6 (via Teredo when needed) + AD-based auth" (MS's previous step was SDI (Server Domain Isolation)) /TJ
-----Original Message----- From: Mark Smith [mailto:nanog@85d5b20a518b8f6864949bd940457dc124746ddc.nosense.org] Sent: Tuesday, April 07, 2009 5:34 PM To: Michael Helmeste Cc: nanog@nanog.org Subject: Re: ACLs vs. full firewalls
On Tue, 07 Apr 2009 13:05:31 -0700 Michael Helmeste <mhelmest@uvic.ca> wrote:
Hi all, One of the duties of my current place of employ is reorganizing the network. We have a few Catalyst 6500 series L3 switches, but currently do all packet filtering (and some routing) using a software based firewall. Don't ask me, I didn't design it :)
Current security requirements are only based on TCP and non-stateful UDP src/dst net/port filtering, and so my suggestion was to use ACLs applied on the routed interface of each VLAN. There was some talk of using another software based firewall or a Cisco FWSM card to filter traffic at the border, mostly for management concerns. We expect full 1 gig traffic levels today, and 10 gig traffic levels in the future.
I view ACLs as being a cheap, easy to administrate solution that scales with upgrades to new interface line speeds, where a full stateful firewall isn't necessary. However, I wanted to get other opinions of what packet filtering solutions people use in the border and in the core, and why.
It seems there is a trend towards moving host protection on to the hosts themselves, onto or closer to the resource or entity being protected. It's basically following the cliche, "If you want something to be done properly, you need to do it yourself."
http://www.opengroup.org/jericho/ - they call it "de-perimeterization"
I first came across the idea in this article:
http://www.cs.columbia.edu/~smb/papers/distfw.html
If you move to the host-based firewalling model, plain packet filtering ACLs at the perimeter would be quite an adequate form of a first level of defence, while also avoiding the performance overhead of (or resources required to perform) stateful tracking of large amounts of traffic.
Regards, Mark.
What's out there, and why do you guys use it? How do you feel about the scalability, performance, security, and manageability of your solution? What kind of traffic levels do you put through it?