Date: Fri, 18 Jan 2002 13:20:01 -0800 (PST) From: "Crist J . Clark" <cristjc@earthlink.net> To: freebsd-bugs@FreeBSD.org Subject: Re: misc/33996: 127.0.0.0/8 not added to routing table by default Message-ID: <200201182120.g0ILK1F27705@freefall.freebsd.org>
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The following reply was made to PR misc/33996; it has been noted by GNATS. From: "Crist J . Clark" <cristjc@earthlink.net> To: Ruslan Ermilov <ru@FreeBSD.ORG> Cc: bug-followup@FreeBSD.ORG Subject: Re: misc/33996: 127.0.0.0/8 not added to routing table by default Date: Fri, 18 Jan 2002 13:07:05 -0800 On Fri, Jan 18, 2002 at 05:40:59PM +0200, Ruslan Ermilov wrote: > On Fri, Jan 18, 2002 at 01:22:34AM -0800, Crist J . Clark wrote: > > On Thu, Jan 17, 2002 at 08:30:02AM -0800, Ruslan Ermilov wrote: > > > The following reply was made to PR misc/33996; it has been noted by GNATS. > > > > > > From: Ruslan Ermilov <ru@FreeBSD.org> > > > To: Aragon Gouveia <aragon@phat.za.net> > > > Cc: bug-followup@FreeBSD.org > > > Subject: Re: misc/33996: 127.0.0.0/8 not added to routing table by default > > > Date: Thu, 17 Jan 2002 18:20:01 +0200 > > > > > > On Thu, Jan 17, 2002 at 08:02:01AM -0800, Aragon Gouveia wrote: > > > > > > > > > > > > The reserved 127.0.0.0/8 range is not added to FreeBSD's routing > > > > table with destination interface lo0 by default. Instead, only > > > > 127.0.0.1/32 is being routed to the loopback interface. Pinging, > > > > for example, 127.2.3.4 returns no response - in my case it tries > > > > to route via the default route out onto the net! > > > > > > > Nah, this is something that should be controlled with a firewall. > > > The default ipfw(8) rules block this. Also, the kernel function > > > in_canforward() does not allow forwarding of IP packets with the > > > destination address in the 127.0.0.0/8 range. > > > > > > Can this PR be closed now? > > > > Well, there is a bug here. Have you ever actually tried, > > > > # ping 127.2.3.4 > > > > And sniffed the wire? That is a Bad Thing. No machine should ever let > > 127/8 on the wire. But I believe there is another PR on this. > > > Yes I tried, and I get EACCES from ipfw(4) because of these lines: > > 00100 allow ip from any to any via lo0 > 00200 deny ip from any to 127.0.0.0/8 > 00300 deny ip from 127.0.0.0/8 to any > > :-) OK, # ipfw d 200 # ping 127.2.3.4 The point being that even without firewalling enabled, I don't think that packets destined for 127/8 should ever leave a host. Well, it's not just me who thinks so, it is a requirement (RFC1122), (g) { 127, <any> } Internal host loopback address. Addresses of this form MUST NOT appear outside a host. -- Crist J. Clark | cjclark@alum.mit.edu | cjclark@jhu.edu http://people.freebsd.org/~cjc/ | cjc@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-bugs" in the body of the message
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