salparadise's questions

Anyone know how I can disable the link-local address from just one interface on CentOS 5.6? This is what I tried:

root-> egrep -i ipv6 /etc/sysconfig/network-scripts/ifcfg-eth0
IPV6INIT=no
IPV6_AUTOCONF=no
IPV6_ROUTER=no

root-> egrep -i ipv6 /etc/sysctl.conf 
#disable ipv6 from eth0
net.ipv6.conf.eth0.disable_ipv6 = 1
net.ipv6.conf.eth0.autoconf = 0

root-> ip -f inet6 a show dev eth0
 2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 fe80::20c:29ff:fe3c:16af/64 scope link 
       valid_lft forever preferred_lft forever


root-> ip -f inet6 a del fe80::20c:29ff:fe3c:16af/64 dev eth0

root-> ip -f inet6 a show dev eth0

Nothing here

But then the address comes back:

root-> ifdown eth0 && ifup eth0

root-> ip -f inet6 a show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qlen 1000
    inet6 fe80::20c:29ff:fe3c:16af/64 scope link 
       valid_lft forever preferred_lft forever

Thanks.

Does anyone know what determines the amount of arp tries a router will make? I have different behaviors with two devices, if I try to traceroute to a non-existent host on a subnet that belongs to an interface on the router, a Linux box will try to arp 3 times and then return a host un-reacheable icmp message. Junos will continuosly try to arp and not return anything. Is there a sysctl value that determines this or anything at all.