Why ue0 do ARP on non local address when using static route?

Jin Guojun jguojun at sbcglobal.net
Wed Feb 13 22:17:28 UTC 2013

/etc/ethers does not help because there is no way resolve the IP by QFHN in 

The correct way is to use router IP ( between and instead of interface IP ( for static route.

From: Chuck Swiger <cswiger at mac.com>
To: Jin Guojun <jguojun at sbcglobal.net>
Cc: questions freebsd <questions at freebsd.org>
Sent: Wed, February 13, 2013 12:55:07 PM
Subject: Re: Why ue0 do ARP on non local address when using static route?

On Feb 13, 2013, at 12:35 PM, Jin Guojun wrote:
> When attached a Trendent TU2-ET100 USB Ether dongle for a second interface, it 

> has no problem to talk to the local network (, but it has 
> to talk to a remote network or host ( via eu0 interface.
> When a remote host ping this host or this host ping that remote host, ARP 
> request is always showing up.
> A static route is set and remote host is no part of the local sub net, why ARP 

> is going on?

You've told the interface that it can reach via, 
which is
the IP ue0 was configured to use.  It sends ARPOP_REQUESTS to get the MAC 
address of which is expected to be reachable.

> Is any sysctl parameter can fix this problem?

You can do things like use proxy-arp, or setup /etc/ethers, or NAT, or even 
ue0 to be on the same subnet as instead, perhaps using an alias.


More information about the freebsd-questions mailing list