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References: <20061203174849.GA4561@host.my.domain>
From: Lowell Gilbert <freebsd-questions-local@be-well.ilk.org>
Date: Mon, 04 Dec 2006 10:26:46 -0500
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	3 Dec 2006 19:48:49 +0200")
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Subject: Re: How does my computer work with an empty arp table?
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a@zeos.net writes:

> My computer is connected to ISP via ADSL and works properly.
>
> I typed
>
> arp -a
>
> and saw an empty table, although I pinged successfully an Internet host
> one second ago.
>
> How does it work?
>
> ------------------------------------------------------------
>
> $ ifconfig
> rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
> 	options=8<VLAN_MTU>
> 	inet6 fe80::202:44ff:fe92:1875%rl0 prefixlen 64 scopeid 0x1 
> 	inet 192.168.1.2 netmask 0xffffff00 broadcast 192.168.1.255
> 	ether 00:02:44:92:18:75
> 	media: Ethernet autoselect (100baseTX <full-duplex>)
> 	status: active
> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> mtu 16384
> 	inet6 ::1 prefixlen 128 
> 	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2 
> 	inet 127.0.0.1 netmask 0xff000000 
> ng0: flags=88d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST> mtu 1492
> 	inet6 fe80::202:44ff:fe92:1875%ng0 prefixlen 64 scopeid 0x3 
> 	inet 91.124.65.146 --> 195.5.5.161 netmask 0xffffffff 

Maybe you are connected to your service provider by PPP-over-Ethernet?
In that case, the PPP link (which doesn't need ARP) is your next-hop
to the Internet, rather than the modem on the Ethernet link.