net: Work-around for brain-damaged Cisco equipment with arp-proxy

[oweals/u-boot.git] / net / arp.c

diff --git a/net/arp.c b/net/arp.c
index 908ebf53165a334e25096be1719241db138700e0..0b0ccbb58af4d919dea8e9af1a158d80ad957dfb 100644 (file)
--- a/net/arp.c
+++ b/net/arp.c
@@ -169,6 +169,20 @@ void ArpReceive(struct ethernet_hdr *et, struct ip_udp_hdr *ip, int len)
                NetCopyIP(&arp->ar_tpa, &arp->ar_spa);
                memcpy(&arp->ar_sha, NetOurEther, ARP_HLEN);
                NetCopyIP(&arp->ar_spa, &NetOurIP);
+
+#ifdef CONFIG_CMD_LINK_LOCAL
+               /*
+                * Work-around for brain-damaged Cisco equipment with
+                *   arp-proxy enabled.
+                *
+                *   If the requesting IP is not on our subnet, wait 5ms to
+                *   reply to ARP request so that our reply will overwrite
+                *   the arp-proxy's instead of the other way around.
+                */
+               if ((NetReadIP(&arp->ar_tpa) & NetOurSubnetMask) !=
+                   (NetReadIP(&arp->ar_spa) & NetOurSubnetMask))
+                       udelay(5000);
+#endif
                NetSendPacket((uchar *)et, eth_hdr_size + ARP_HDR_SIZE);
                return;