Date: Thu, 15 Feb 2007 14:15:35 +0200 (EET) From: ea@sellinet.net To: "Sten Daniel Soersdal" <sten.daniel.sorsdal@gmail.com> Cc: freebsd-isp@freebsd.org Subject: Re: [Strange behavior with arp permanent entries] Message-ID: <33702.82.199.192.218.1171541735.squirrel@82.199.192.218> In-Reply-To: <45D34E49.8090808@gmail.com> References: <2947.82.199.223.6.1171128810.squirrel@82.199.223.6> <45D34E49.8090808@gmail.com>
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> ea@sellinet.net wrote: >> Hello, Guys! >> >> I'm trying to restrict some LAN access by arp permanent entries. But it >> didn't work or it didn't work as I realize it. For example I have the >> following perm entries: >> >> >> user1: (82.199.215.195) at 00:0f:ea:a4:60:c5 on vlan804 permanent [vlan] >> user2: (82.199.215.196) at 00:13:8f:b1:68:4b on vlan804 permanent [vlan] >> >> >> And from what I realize if the user1 attempts to use user2's IP address. >> The Router should block all packets which coming from wrong physical >> address. But actually that didn't happen and user1 can use user2's IP >> address without any problems. > > The router wont block packets coming from anyone. It should however > prevent packets going *to* the wrong user. But that depends heavily on > whether the layer2 network cooperates and the bad hosts network stack. Scenario 1: user1: 10.2.0.2 00:14:85:84:af:c8 perm user2: 10.2.0.3 00:0f:ea:a4:60:c5 perm User2 can't use user1's IP address. Scenario 2: user1: 10.2.0.2 00:0a:e6:f7:8a:81 perm user2: 10.2.0.3 00:0f:ea:a4:60:c5 perm User2 can use user1's IP address. So, maybe there is some truth in your words, but why this happen? What is the difference between two physical addresses? > > Tip: If you want the effect of each user having their own physical lan > (so they can't steal each others ip addresses) you need to segregate > them in a manner that effectively gives each user a physical lan. Vlans > might help, if done correctly. Unfortunately, this can't be done in our case. > >> >> Maybe someone of you will advice me to use ipfw arp rules but when I >> turn >> net.link.ether.ipfw ON I'm getting very low performance from the router. >> We talking about 800mbps and 600k packets per second, and many users >> which >> means many ipfw arp rules. > > Then perhaps you need to solve the problem on a different level or > different unit? Perhaps segregate the users at edge using vlans and thus > removing filter needs? > > -- > Sten Daniel Soersdal > _______________________________________________ > freebsd-isp@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-isp > To unsubscribe, send any mail to "freebsd-isp-unsubscribe@freebsd.org" > -------------------------------------------------------------- SELLINET Internet Services Provider - http://www.sellinet.net/
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