similar to: Firewall rules that discriminate by connection duration

We're being ping-flooded by the Nachi worm, which probes subnets for systems to attack by sending 92-byte ping packets. Unfortunately, IPFW doesn't seem to have the ability to filter packets by length. Assuming that I stick with IPFW, what's the best way to stem the tide? --Brett Glass

I need to build up a few servers and routers, and am wondering how FreeBSD 9.1 is shaping up. Will it be likely to be more stable and robust than 9.0-RELEASE? Are there issues that will have to wait until 9.2-RELEASE to be fixed? Opinions welcome. --Brett Glass

Everyone: We're starting to see a rash of password guessing attacks via SSH on all of our exposed BSD servers which are running an SSH daemon. They're coming from multiple addresses, which makes us suspect that they're being carried out by a network of "bots" rather than a single attacker. But wait... there's more. The interesting thing about these attacks is that

I would like to request that some useful work on networking be MFCed from -CURRENT to -STABLE in time for the release of FreeBSD 6.3. In particular, I'd like to see some of the Netgraph nodes which are new or which have seen extensive development brought in -- ng_nat and ng_car in particular. Bringing in the latest version of ng_nat would allow more flexible in-kernel NAT, while ng_car (which

Hey Guys, today I upgraded to 4.8-RELEASE-p15. As usual I set IPFIREWALL to default accept in my kernel config file. Config & make weren't complaining so, installed the kernel, reboot and there it was: >IP packet filtering initialized, divert disabled, rule-based forwarding enabled, default to deny, logging disabled Another rebuild didn't work out so... I reviewed

A client wants me to set up a mechanism whereby his customers can drop files securely into directories on his FreeBSD server; he also wants them to be able to retrieve files if needed. The server is already running OpenSSH, and he himself is using Windows clients (TeraTerm and WinSCP) to access it, so the logical thing to do seems to be to have his clients send and receive files via SFTP or SCP.

Hi. On my FreeBSD 4.8 configured IPFW2+IPF+IPNAT and I use them all: - IPFW - traffic accounting, shaping, balancing and filtering; - IPFilter - policy routing; - IPNAT - masquerading. I want to know, how IP-packets flow through all of this components? What's the path? incoming: IPFW Layer2 -> IPFW&Dummynet -> IPNAT -> IPFilter ? outgoing: IPFW Layer2 ->

In the next month or two I've got to upgrade a number of servers that are currently on an EOL'd version of 4-STABLE. I foresee that I'll have very limited time to do full OS upgrades on these systems in the coming several years, so I want to make sure I bring them onto an extended-life branch. Right now 4.11 has the furthest projected EOL date (Jan 31 2007), and the projected EOL

OK, an official OpenSSH advisory was released, see here: <URL: http://www.mindrot.org/pipermail/openssh-unix-announce/2003-September/000063.html > The fix is currently in FreeBSD -CURRENT and -STABLE. It will be applied to the security branches as well today. Attached are patches: buffer46.patch -- For FreeBSD 4.6-RELEASE and later buffer45.patch -- For FreeBSD 4.5-RELEASE and

I'm constructing a Web server which may require restricted areas of the site to be used from public places where a password might be sniffed. The damage that could be done by taking snapshots of the content from one session with a spy program is minimal. What the owner of the server does NOT want, though, is to allow unauthorized parties to gain unfettered access by stealing the password via

Hi. We just opened a gaming center and have chosen to run a FreeBsd box for our firewall. IPFW is configured at it's very basic running natd through rl0 and allowing any to any connections from the lan to the outer world. Natd controls access to the lan. We have a 6.0 mb/s ADSL net connection for all the gaming clients to use, however if a gamer starts downloading a file, that file

Hi, in the kernel I have these lines: [...] device miibus # MII bus support device rl device ed options IPFIREWALL #firewall options IPFIREWALL_VERBOSE #enable logging to syslogd(8) options IPFIREWALL_VERBOSE_LIMIT=0 #limit verbosity options IPDIVERT #divert sockets options DUMMYNET

Hi, I got this error when i tried to type for some of those. "sysctl: unknown oid...." any idea.. my server seems to be very lagged, where else the network connection seems fine, i think BSD itself as my other redhat box is fine. What else can i do to get optimum protection. Thanks. ----- Original Message ----- From: "Per Engelbrecht" <per@xterm.dk> To:

root@vigilante /root cuaa1# man init |tail -n 130 |head -n 5 3 Network secure mode - same as highly secure mode, plus IP packet filter rules (see ipfw(8) and ipfirewall(4)) cannot be changed and dummynet(4) configuration cannot be adjusted. root@vigilante /root cuaa1# sysctl -a |grep secure kern.securelevel: 3 root@vigilante /root cuaa1# ipfw show 00100 0 0 allow

Scenario: FreeBSD box running IPFW acting as a gateway to private network. The private network is made up of entirely routeable IP addresses. External users running Win2k and XP on DSL connections with dynamic IPs. Goal: To have the FreeBSD gateway securely authenticate and encrypt the traffic between the outside users and the internal network. I've spent the last 3 days running up and

Hi all, First of all, I have spent a lot of time reading up on it. Anyway, I live in a shared accomodation with 2 roommates and a landlord and we share a cable internet connection. It is 2Mbit/400Kbit connection. Sometimes when one of us is downloading a song through Kazaa or a new Linux or FreeBSD iso, the bandwidth gets hogged and other users can't get through. I was trying to configure

Hi there, Is there some way to configure ipfw to do traffic normalizing ("scrubbing", as in ipf for OpenBSD)? Is there any tool to do it for FreeBSD firewalling? I've heard that ipf was ported on current, anything else? TIA, /Dorin. __________________________________ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools

I'm working with a FreeBSD user -- a teacher -- who's running KDE on a system on which she neither has nor wants root privileges. She wants to be able to mount and unmount floppies and ZIP cartridges from within KDE, using the standard KwikDisk utility (which, by the way, generates mount and unmount command that don't conform to FreeBSD syntax; however, it appears possible to fix this

All: I'm posting this to FreeBSD-security (rather than FreeBSD-net) because the problems I'm seeing appear to have been caused by spyware, and because they constitute a possible avenue for denial of service on FreeBSD machines with default installs of the operating system. Several of the FreeBSD machines on our network began to act strangely during the past week. Some have started to

I am trying to limit outgoing SMTP traffic to about 14 Mbps and these are the IPFW rules I am using. ${fwcmd} add pipe 1 tcp from 192.168.0.0/24 to any 25 out via dc0 ${fwcmd} pipe 1 config bw 14Mbit/s I've tried multiple tweaks to the pipe rule and I seem to be missing something. I only get about half the bandwidth I specify. Is this normal behavior? Is there something wrong