nanog mailing list archives
Re: Barracuda Networks Spam Firewall
From: "Jared B. Reimer" <jared () theriver com>
Date: Mon, 17 May 2004 14:26:37 -0700
Did you not receive some basic support from them during your evaluation? A perceived 90% drop in performance is pretty significant and I'd imagine that they'd be interested in helping to determine the cause.
Sadly, they have not responded to my email on the topic, sent four days ago.However, someone unrelated to the company emailed me off-list saying that basically this is a known flaw in the product with back-end systems like qmail that asynchronously bounce mail for invalid recipients. See below quote:
We had this problem when our inbound-smtp server ( the server the barracuda is dumping mail to) was accepting all RCPT TOs: As a result dictionary attacks were getting through and creating 'unique recipients' on the Barracuda. As soon as I fixed my mail server to reject with a 220 error on bogus RCPT TOs the problem cleared up.
This is a pretty serious flaw IMHO, if it is (in fact) true. qmail isn't the only mailer that behaves this way. It looks like they may have tried to kludge their way around this with LDAP in the case of MS Exchange, which also does asynchronous bouncing of undeliverable mail IIRC.
-- Jared
Current thread:
- Re: Barracuda Networks Spam Firewall, (continued)
- Re: Barracuda Networks Spam Firewall Martin Hepworth (May 18)
- Re: Barracuda Networks Spam Firewall Matthew Crocker (May 18)
- Re: Barracuda Networks Spam Firewall Martin Hepworth (May 18)
- Port 5000 Geo. (May 18)
- Re: Port 5000 Erik Haagsman (May 18)
- Re: Port 5000 Doug White (May 18)
- Re: Port 5000 James Reid (May 18)
- Re: Barracuda Networks Spam Firewall Jared B. Reimer (May 17)
- Re: Barracuda Networks Spam Firewall Jared B. Reimer (May 17)
- Re: Barracuda Networks Spam Firewall jlewis (May 17)
- Re: Barracuda Networks Spam Firewall Majdi S. Abbas (May 18)
- Re: Barracuda Networks Spam Firewall Valdis . Kletnieks (May 18)
- Re: Barracuda Networks Spam Firewall Christopher X. Candreva (May 18)
- Re: Barracuda Networks Spam Firewall Valdis . Kletnieks (May 18)
- Re: Barracuda Networks Spam Firewall Todd Vierling (May 18)
- Re: Barracuda Networks Spam Firewall Christopher X. Candreva (May 18)