Re: arp, kernel 2.2.15 and 2.3.99-pre6

From: Ville Nummela (
Date: Thu May 04 2000 - 23:49:08 EST

On Thu, 4 May 2000 wrote:

> Please, hold one statement involatile: you must answer to unicast
> ARP requests, not depending on anything. Host cannot know, how
> requestor got initial information about your MAC.

RFC2002, section 4.6:
   Finally, while the
   mobile node is away from home, it MUST NOT reply to ARP Requests
   in which the target IP address is its own home address, unless the
   ARP Request is sent by a foreign agent with which the mobile node
   is attempting to register or a foreign agent with which the mobile
   node has an unexpired registration.

Actually, know one should know the ethernet address of the mobile node
(when the mobile node leaves home network, home agent sends gratuitous arp
for it with its own ethernet address).
My solution to this was disabling ARP from the kernel totally and let the
mobile node software do ARP handling. I do have to admit now that Andi's
patch is probably a better solution; With it the mobile node software does
not have to answer to incoming ARP requests since the kernel does it "the
right way". At least if it works how I've understood from the source, I
haven't had time to test it in action yet.

 | work: +358-5-4125389 home: +358-40-5075560     |        
 | 	     ViGe / gasp inc. |	    |
 | 	   "Bother," said Pooh, and deleted his message base.       |

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to Please read the FAQ at

This archive was generated by hypermail 2b29 : Sun May 07 2000 - 21:00:16 EST