Firewall Wizards mailing list archives
Re: Firewalls and 802.1q trunking
From: Jonn Martell <jonn.martell () ubc ca>
Date: Wed, 27 Nov 2002 17:08:06 -0800 (PST)
Additional things to watch out for: IVL/SVL With SVL (shared vlan learning) a MAC address cannot show up on two different VLANs without causing problems. If you are going to do this, make sure your VLAN switch supports IVL (independent VLAN learning). You also need to keep management of your switch locked down to prevent someone from changing the VLAN settings. On 27 Nov 2002, Steffen Kluge wrote:
Date: 27 Nov 2002 11:30:44 +1100 From: Steffen Kluge <kluge () fujitsu com au> To: "'firewall-wizards () honor icsalabs com'" <firewall-wizards () honor icsalabs com> Subject: [fw-wiz] Firewalls and 802.1q trunking Hi everyone, I'd like to solicit your opinion on the popular trend of equipping firewalls with (almost) arbitrary numbers of interfaces by means of VLAN trunking. Many FW vendors (including Nokia, NetScreen, and the like) are going down that path. My concern is that the "fan-out" boxes are typically run-of-the-mill switches, like Cisco Catalysts, that probably have been design without any security aspirations. I wouldn't be surprised if those switches could be attacked and tricked into leaking packets between VLANs. Are there any studies devoted to this issue, or reports of successful attacks against 802.1q separation that I should be aware of? In our environment we use firewalls with rather large numbers of interfaces (typically 15 ~ 25), mostly based on Xylan switches running FW-1. This product line has disappeared now and all alternative solutions seem to be relying on VLAN trunking. I'm not comfortable with the idea yet, but I wasn't comfortable with the Xylan switches in the beginning, either. I'd like to think I'm too paranoid, but then, that's my job... Cheers Steffen. _______________________________________________ firewall-wizards mailing list firewall-wizards () honor icsalabs com http://honor.icsalabs.com/mailman/listinfo/firewall-wizards
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Current thread:
- Firewalls and 802.1q trunking Steffen Kluge (Nov 26)
- Re: Firewalls and 802.1q trunking Two Dog Flats (Nov 26)
- Re: Firewalls and 802.1q trunking Carson Gaspar (Nov 26)
- Re: Firewalls and 802.1q trunking David Pick (Nov 27)
- Re: Firewalls and 802.1q trunking ark (Nov 27)
- Re: Firewalls and 802.1q trunking R. DuFresne (Nov 27)
- Re: Firewalls and 802.1q trunking Jonn Martell (Nov 27)
- <Possible follow-ups>
- Re: Firewalls and 802.1q trunking Pearsall, Jim (Nov 27)
- Re: Firewalls and 802.1q trunking David Pick (Nov 27)
- Re: Firewalls and 802.1q trunking Stephen Gill (Nov 27)