Hi folks, I have run through what you asked, at what seems to be happening is that, indeed, a second entry is getting added to the local route table but with a different "src", that being the "new" address. Is this a kernel issue or an ifconfig problem? Thanks, Tim [root@nfstest root]# ifconfig eth0:5 10.12.0.22 netmask 255.255.0.0 up [root@nfstest root]# ip addr 1: lo: <LOOPBACK,UP,10000> mtu 16436 qdisc noqueue link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever 5: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000 link/ether 00:80:ad:72:3e:5a brd ff:ff:ff:ff:ff:ff inet 10.12.0.20/16 brd 10.12.255.255 scope global eth0 inet 10.12.0.22/16 brd 10.12.255.255 scope global secondary eth0:5 inet6 fe80::280:adff:fe72:3e5a/64 scope link valid_lft forever preferred_lft forever 6: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000 link/ether 00:80:ad:20:59:8b brd ff:ff:ff:ff:ff:ff 7: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000 link/ether 00:01:02:c6:fe:c1 brd ff:ff:ff:ff:ff:ff 8: sit0: <NOARP> mtu 1480 qdisc noop link/sit 0.0.0.0 brd 0.0.0.0 [root@nfstest root]# ping 10.12.0.22 PING 10.12.0.22 (10.12.0.22) 56(84) bytes of data. 64 bytes from 10.12.0.22: icmp_seq=0 ttl=64 time=0.086 ms 64 bytes from 10.12.0.22: icmp_seq=1 ttl=64 time=0.071 ms --- 10.12.0.22 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1009ms rtt min/avg/max/mdev = 0.071/0.078/0.086/0.011 ms, pipe 2 [root@nfstest root]# ip route list table local broadcast 127.255.255.255 dev lo proto kernel scope link src 127.0.0.1 broadcast 10.12.255.255 dev eth0 proto kernel scope link src 10.12.0.20 local 10.12.0.20 dev eth0 proto kernel scope host src 10.12.0.20 local 10.12.0.22 dev eth0 proto kernel scope host src 10.12.0.20 broadcast 10.12.0.0 dev eth0 proto kernel scope link src 10.12.0.20 broadcast 127.0.0.0 dev lo proto kernel scope link src 127.0.0.1 local 127.0.0.1 dev lo proto kernel scope host src 127.0.0.1 local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1 [root@nfstest root]# ifconfig eth0:5 10.12.0.22 netmask 255.255.0.0 down [root@nfstest root]# ip route list table local broadcast 127.255.255.255 dev lo proto kernel scope link src 127.0.0.1 broadcast 10.12.255.255 dev eth0 proto kernel scope link src 10.12.0.20 local 10.12.0.20 dev eth0 proto kernel scope host src 10.12.0.20 broadcast 127.0.0.0 dev lo proto kernel scope link src 127.0.0.1 local 127.0.0.1 dev lo proto kernel scope host src 127.0.0.1 local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1 [root@nfstest root]# ifconfig eth0:5 10.12.0.22 netmask 255.255.0.0 up [root@nfstest root]# ip route list table local broadcast 127.255.255.255 dev lo proto kernel scope link src 127.0.0.1 broadcast 10.12.255.255 dev eth0 proto kernel scope link src 10.12.0.20 local 10.12.0.20 dev eth0 proto kernel scope host src 10.12.0.20 local 10.12.0.22 dev eth0 proto kernel scope host src 10.12.0.20 broadcast 127.0.0.0 dev lo proto kernel scope link src 127.0.0.1 local 127.0.0.1 dev lo proto kernel scope host src 127.0.0.1 local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1 [root@nfstest root]# ifconfig eth0:6 10.12.0.22 netmask 255.255.0.0 up SIOCSIFFLAGS: Cannot assign requested address [root@nfstest root]# ip route list table local broadcast 127.255.255.255 dev lo proto kernel scope link src 127.0.0.1 broadcast 10.12.255.255 dev eth0 proto kernel scope link src 10.12.0.20 local 10.12.0.20 dev eth0 proto kernel scope host src 10.12.0.20 local 10.12.0.22 dev eth0 proto kernel scope host src 10.12.0.20 local 10.12.0.22 dev eth0 proto kernel scope host src 10.12.0.22 broadcast 127.0.0.0 dev lo proto kernel scope link src 127.0.0.1 local 127.0.0.1 dev lo proto kernel scope host src 127.0.0.1 local 127.0.0.0/8 dev lo proto kernel scope host src 127.0.0.1 - To unsubscribe from this list: send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html