• Denys Fedoryshchenko's avatar
    ipv4: arp announce, arp_proxy and windows ip conflict verification · 73ce7b01
    Denys Fedoryshchenko authored
    Windows (XP at least) hosts on boot, with configured static ip, performing 
    address conflict detection, which is defined in RFC3927.
    Here is quote of important information:
    
    "
    An ARP announcement is identical to the ARP Probe described above, 
    except    that now the sender and target IP addresses are both set 
    to the host's newly selected IPv4 address. 
    "
    
    But it same time this goes wrong with RFC5227.
    "
    The 'sender IP address' field MUST be set to all zeroes; this is to avoid
    polluting ARP caches in other hosts on the same link in the case
    where the address turns out to be already in use by another host.
    "
    
    When ARP proxy configured, it must not answer to both cases, because 
    it is address conflict verification in any case. For Windows it is just 
    causing to detect false "ip conflict". Already there is code for RFC5227, so 
    just trivially we just check also if source ip == target ip.
    Signed-off-by: default avatarDenys Fedoryshchenko <denys@visp.net.lb>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    73ce7b01
arp.c 34.5 KB