About a week ago a customer hooked up a wireless router backwards to our network, causing it to serve incorrect DHCP addresses to some of them. Our networks are mostly statically assigned so this didn't cause as much damage as it might have, but now, over a week later, I still have incomplete 192.168.10.x entries stuck in the ARP table:
$ arp -n
Address HWtype HWaddress Flags Mask Iface
192.168.20.27 ether 00:60:B3:20:71:32 C lan
192.168.20.36 ether 00:15:E9:84:E8:60 C lan
192.168.20.64 ether 00:22:5F:14:B4:75 C lan
192.168.10.101 (incomplete) lan
192.168.20.33 ether 00:13:4F:00:A2:85 C lan
192.168.10.84 (incomplete) lan
208.92.117.109 ether 00:80:AE:97:78:1F C wan
192.168.10.65 (incomplete) lan
192.168.20.46 ether 00:07:E9:BD:FB:79 C lan
192.168.10.90 (incomplete) lan
192.168.20.130 ether 00:60:B3:07:10:16 C lan
192.168.20.21 ether 00:13:4F:00:40:85 C lan
192.168.10.88 (incomplete) lan
192.168.20.43 ether 00:15:E9:32:C4:F1 C lan
192.168.20.14 ether 00:13:4F:00:64:FF C lan
$
arp -d cannot delete the incomplete entries, and they won't go away. I suppose they're harmless but I'd get rid of them if I could. Is there any better way than a reboot?