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Date:      Thu, 8 Nov 2001 09:55:57 -0600 (CST)
From:      Scott Pilz <tech@squid.tznet.com>
To:        Michael Lucas <mwlucas@blackhelicopters.org>
Cc:        freebsd-questions@FreeBSD.ORG
Subject:   Re: arplookup failed
Message-ID:  <Pine.BSF.4.05.10111080955470.29167-100000@squid.tznet.com>
In-Reply-To: <20011108103403.A8775@blackhelicopters.org>

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	The majority of them are gonna be NT unfortunnatly.

On Thu, 8 Nov 2001, Michael Lucas wrote:

> 
> 
> Well, you now know the full nature of your doom, at least.
> 
> Another thought: are the .68 machines virtual hosts, or are you
> actually putting 256x5 physical hosts on the network?
> 
> If they're virtual hosts, you can do something like this:
> 
> ifconfig fxp0 inet x.y.64.2
> ifconfig fxp0 alias x.y.68.1
> ifconfig fxp0 alias x.y.68.2
> <repeat 253 more aliases>
> ....
> 
> 
> Then you route the entire .68 block to x.y.64.2, and the problem will
> go away.
> 
> On Thu, Nov 08, 2001 at 09:25:39AM -0600, Scott Pilz wrote:
> > 
> > 	Well, it's a block of five . . .
> > 
> > 64 - 1
> > 65 - 2
> > 66 - 3
> > 67 - 4
> > 68 - 5
> > 
> > I'd need a /22 on 64 and a /24 on 68, that would solve the problems with
> > 64-67, but not 68, which will also be pretty important.. darn it.
> > 
> > Scott
> > 
> > On Thu, 8 Nov 2001, Michael Lucas wrote:
> > 
> > > So, you're putting 64-68 on your local network permanently?
> > > 
> > > That's a block of 4, or a /22.
> > > 
> > > Change your netmask to /22, so that you have a legitimate local
> > > network.  That will fix the problem.
> > > 
> > > 
> > > 
> > > On Thu, Nov 08, 2001 at 09:15:28AM -0600, Scott Pilz wrote:
> > > > 
> > > > 	Ouch.
> > > > 
> > > > 	I hate your answer :-)
> > > > 
> > > > 	But if I have to live with it, I'll live with it.
> > > > 
> > > > 	I'd like to keep things as near as possible.. .64 - .68 are going
> > > > to remain in our CO. The rest will be shipped out to 5 different
> > > > locations. Some machines will be running multiple class c's (the one I'm
> > > > on, for example, runs both on the 68 block ((one address) and on the 64
> > > > block (3 more addresses).
> > > > 
> > > > 	I think I know a stupid way around it -- using the route command I
> > > > could route entire subnets to the ethernet instead of the router.. But
> > > > that is a pain in the butt.. I have 9 some freebsd machines here, getting
> > > > more in soon -- not to mention all the crap NT machines (which handle this
> > > > problem without a trace by the way).. 
> > > > 
> > > > I wish I could disable this arp lookup, but I won't worry about it.
> > > > 
> > > > Scott
> > > > 
> > > > On Thu, 8 Nov 2001, Michael Lucas wrote:
> > > > 
> > > > > Well, yes, and you won't like it.  :)
> > > > > 
> > > > > If I understand you correctly, you have two machines on one Ethernet
> > > > > network.  Each is part of a different block of IP addresses.  Correct?
> > > > > 
> > > > > If that's correct, what you're describing is just wrong.  It works,
> > > > > mind you, but it's technically wrong.  arplookup is trying to map an
> > > > > Ethernet address to an IP address, as the response comes back via
> > > > > Ethernet.  And it gets an impossible answer, and complains.
> > > > > 
> > > > > The arplookup message is FreeBSD's way of saying "I sent a message to
> > > > > this router, and it came back over the Ethernet, from an address that
> > > > > I know isn't on the ethernet.  What the &*(!#& are you doing up there,
> > > > > Mr Administrator Sir?"
> > > > > 
> > > > > The upshot is, ignore it.  It's harmless.  Having worked at an ISP for
> > > > > too many years, I assume you're doing this temporarily and will be
> > > > > shipping one box or the other to a location where that network number
> > > > > is appropriate.
> > > > > 
> > > > > On Thu, Nov 08, 2001 at 08:59:26AM -0600, Scott Pilz wrote:
> > > > > > 
> > > > > > 	Basically we have our main router plugged into a switch - where
> > > > > > the LAN is at.. A pretty basic configuration. 
> > > > > > 
> > > > > > Say that I have the IP address of 66.170.64.x on a machine, netmask of
> > > > > > 255.255.255.0 ...
> > > > > > 
> > > > > > On another machine, I have the ip address of 66.170.68.x, netmask of
> > > > > > 255.255.255.0 ..
> > > > > > 
> > > > > > Assuming that the first one is FreeBSD, I will get the arp lookup failed
> > > > > > message when I attempt to ping the .68.x machine - BUT it will still ping.
> > > > > > For that matter, it's one hop away - it actually jumps to the router, then
> > > > > > to that machine.
> > > > > > 
> > > > > > Any ideas at all ? :(
> > > > > > 
> > > > > > On Thu, 8 Nov 2001, Michael Lucas wrote:
> > > > > > 
> > > > > > > Ah, so much for the easy answer.  I wondered how you had a /20 on your
> > > > > > > local network.  :)
> > > > > > > 
> > > > > > > Are these machines you're trying to hit elsewhere on your network
> > > > > > > (i.e., past the router)?  In that case, is your default route set
> > > > > > > properly?  Do a "netstat -nr" and see.
> > > > > > > 
> > > > > > > If you have a default router, then run a traceroute and see where it
> > > > > > > dies.
> > > > > > > 
> > > > > > > On Thu, Nov 08, 2001 at 08:48:43AM -0600, Scott Pilz wrote:
> > > > > > > > Well, there are some problems with doing this however.
> > > > > > > > 
> > > > > > > > We don't want/can't have the entire /20 routed to just our main office. We
> > > > > > > > have POP's all over the state that we will be sooner or later routing the
> > > > > > > > addresses out to. The last block, being 66.170.79.255 would at that point
> > > > > > > > be the broadcast -- but it won't even be routed to this router much
> > > > > > > > longer, so it won't work.
> > > > > > > > 
> > > > > > > > Any other ideas?
> > > > > > > > 
> > > > > > > > On Thu, 8 Nov 2001, Michael Lucas wrote:
> > > > > > > > 
> > > > > > > > > On Thu, Nov 08, 2001 at 07:31:18AM -0600, Scott Pilz wrote:
> > > > > > > > > > 
> > > > > > > > > > 	I've seen many posts on freebsd-questions but no answers that have
> > > > > > > > > > helped me with this problem.
> > > > > > > > > > 
> > > > > > > > > > We have recently obtained a new block of address space (66.170.64.1/20).
> > > > > > > > > > 
> > > > > > > > > > I run around 8-10 FreeBSD machines in the office, every one has the same
> > > > > > > > > > problem .. .
> > > > > > > > > > 
> > > > > > > > > > They are on the 66.170.64.x block, netmask of 255.255.255.0.
> > > > > > > > > > 
> > > > > > > > > > Upon trying to ping another machine -- NT lets say, that has the address
> > > > > > > > > > of 66.170.68.x, or 65.x, etc. will issue the following error:
> > > > > > > > > > 
> > > > > > > > > > /kernel: arplookup 66.170.xx.xxx failed: host not on local network.
> > > > > > > > > > 
> > > > > > > > > > Now, there MUST be a way to easily fix this. I'm sure it's just a
> > > > > > > > > > configuration problem, please advise.
> > > > > > > > > 
> > > > > > > > > You need to fix your netmask.  You have a netmask of /20, yet your
> > > > > > > > > machines are set to /24.
> > > > > > > > > 
> > > > > > > > > The error means exactly what it says: 66.170.68.xx is not on the local
> > > > > > > > > network.
> > > > > > > > > 
> > > > > > > > > Set your netmask to /20, and it will just work.
> > > > > > > > > 
> > > > > > > > > 
> > > > > > > > > -- 
> > > > > > > > > Michael Lucas
> > > > > > > > > mwlucas@blackhelicopters.org
> > > > > > > > > http://www.blackhelicopters.org/~mwlucas/
> > > > > > > > > Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons
> > > > > > > > > 
> > > > > > > 
> > > > > > > -- 
> > > > > > > Michael Lucas
> > > > > > > mwlucas@blackhelicopters.org
> > > > > > > http://www.blackhelicopters.org/~mwlucas/
> > > > > > > Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons
> > > > > > > 
> > > > > 
> > > > > -- 
> > > > > Michael Lucas
> > > > > mwlucas@blackhelicopters.org
> > > > > http://www.blackhelicopters.org/~mwlucas/
> > > > > Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons
> > > > > 
> > > 
> > > -- 
> > > Michael Lucas
> > > mwlucas@blackhelicopters.org
> > > http://www.blackhelicopters.org/~mwlucas/
> > > Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons
> > > 
> 
> -- 
> Michael Lucas
> mwlucas@blackhelicopters.org
> http://www.blackhelicopters.org/~mwlucas/
> Big Scary Daemons: http://www.oreillynet.com/pub/q/Big_Scary_Daemons
> 


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