Messages in this thread |  | | Date | Fri, 19 Oct 2001 15:57:22 -0400 | From | "Christopher Friesen" <> | Subject | Re: how to see manually specified proxy arp entries using "ip neigh" |
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"Matthew G. Marsh" wrote:
> > Currently I have been doing this by manually setting proxy arping on the NIC for > > the IP address assigned to the ethertap device. If this feature is going to be > > removed, then how should I be doing this? > > If an IP address is routed to on the external network then it will be > available. It does _not_ matter what interface that address is assigned > to. EX: > > ip addr add 10.1.1.1/24 dev dummy0 > ip link set dev dummy0 up > > now ping 10.1.1.1 from another machine on eth0 that has an appropriate > route. I suspect what is really biting you is that your rp_filters are way > too restrictive on your machine.
Sorry, I guess I explained it wrong. Ethertap has an IP address assigned to the device in the linux kernel. It is then configured with a point to point route to another IP address on the other concepual end of the link (ie in userspace). It is this other IP address that I am proxy arping for.
Thus,
[mtc@10.40.14.70 mtc]$ /sbin/ip add <stuff removed> 4: tap0: <BROADCAST,MULTICAST,NOARP,UP> mtu 1500 qdisc noqueue link/ether fe:fd:00:00:00:00 brd ff:ff:ff:ff:ff:ff inet 10.40.14.73 peer 10.40.14.74/32 brd 10.40.14.255 scope global tap0
[mtc@10.40.14.70 mtc]$ /sbin/ip ro 10.40.14.74 dev tap0 proto kernel scope link src 10.40.14.73 <stuff removed>
[mtc@10.40.14.70 mtc]$ /sbin/arp Address HWtype HWaddress Flags Mask Iface <stuff removed 10.40.14.74 * * MP eth1
Thus, anyone arping for 10.40.14.74 (which is on top of a protocol stack in userspace) will get the MAC address of eth1 as a response.
I cannot turn on proxy arping for the interface in general as I have eth0 and eth1 on the same subnet and turning on proxy arping causes bad things to happen. Thus I have a single manual proxy entry in the arp table.
-- Chris Friesen | MailStop: 043/33/F10 Nortel Networks | work: (613) 765-0557 3500 Carling Avenue | fax: (613) 765-2986 Nepean, ON K2H 8E9 Canada | email: cfriesen@nortelnetworks.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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