Firewall Wizards mailing list archives
Re: Layer 2 (stealth) firewalls - PBR?
From: "Paul D. Robertson" <paul () compuwar net>
Date: Tue, 8 Apr 2008 10:10:14 -0400 (EDT)
On Mon, 7 Apr 2008, Darden, Patrick S. wrote:
Except that a layer two device can't tell if something is multicast or broadcast or unicast or Anything in ipv4 or ipv6.... That's sorta the definition of a layer two device. If it could discriminate amongst layer 3 traffic, it would be a layer 3 device--a router, firewall, etc.
I've been doing networking since the broadband/baseband LAN thing a long time ago, and I'm pretty cognizant of how it all works... Layer 2 devices like switches have to forwrd layer 3 multicast packets out ports for the multicast group, so they in essence have to peek up a layer even though they're not "routers, firewalls, etc." They also have to forward layer 3 broadcasts out all ports in a LAN or VLAN, once again without being "routers, firewalls, etc." Finally, there are alyer 2 broadcasts and layer 2 multicast addresses. I'd suggest a Google of "layer 2 multicast addresss" for your increased edification, and a good read of the IPv6 RFCs- because if you don't think this stuff is going to be where "interesting" attacks and "poor implementations" happen... Paul ----------------------------------------------------------------------------- Paul D. Robertson "My statements in this message are personal opinions paul () compuwar net which may have no basis whatsoever in fact." http://www.fluiditgroup.com/blog/pdr/ Art: http://PaulDRobertson.imagekind.com/ _______________________________________________ firewall-wizards mailing list firewall-wizards () listserv icsalabs com https://listserv.icsalabs.com/mailman/listinfo/firewall-wizards
Current thread:
- Layer 2 (stealth) firewalls - PBR? Darren Reed (Apr 01)
- Re: Layer 2 (stealth) firewalls - PBR? Sami Ghourabi (Apr 01)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 02)
- Re: Layer 2 (stealth) firewalls - PBR? Darren Reed (Apr 02)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 03)
- Re: Layer 2 (stealth) firewalls - PBR? Paul D. Robertson (Apr 03)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 08)
- Re: Layer 2 (stealth) firewalls - PBR? Paul D. Robertson (Apr 08)
- Re: Layer 2 (stealth) firewalls - PBR? Patrick Darden (Apr 08)
- Re: Layer 2 (stealth) firewalls - PBR? Paul D. Robertson (Apr 08)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 10)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 02)
- Re: Layer 2 (stealth) firewalls - PBR? Sami Ghourabi (Apr 01)
- Layer 2 (stealth) firewalls - PBR? iarenaza (Apr 09)
- Re: Layer 2 (stealth) firewalls - PBR? Darden, Patrick S. (Apr 10)
- Re: Layer 2 (stealth) firewalls - PBR? lordchariot (Apr 10)
- Message not available
- Re: Layer 2 (stealth) firewalls - PBR? Darren Reed (Apr 08)
- <Possible follow-ups>
- Re: Layer 2 (stealth) firewalls - PBR? Paul D. Robertson (Apr 10)