[ILUG] ARP Insanity!
nickm at go2.ie
Tue Feb 21 12:04:46 GMT 2006
I've moved an IP address from server A to server B.
Server A is still responding to ARP requests for the IP address!
The interface on Server A that had the IP address has been removed,
and networking has since been restarted. No software is listening on
that IP address.
Both servers are Ubuntu Breezy.
On Server A:
# netstat -anp -A inet | grep 10.2.1.230
Also on Server A:
# ip addr
1: lo: <LOOPBACK,UP> 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
2: eth0: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:14:22:b0:5e:80 brd ff:ff:ff:ff:ff:ff
inet 10.2.1.15/24 brd 10.255.255.255 scope global eth0
inet 10.2.1.231/24 brd 10.255.255.255 scope global secondary eth0:0
inet 10.2.1.16/24 brd 10.255.255.255 scope global secondary eth0:1
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop qlen 1000
link/ether 00:14:22:b0:5e:81 brd ff:ff:ff:ff:ff:ff
From a third machine:
# arping 10.2.1.230
ARPING 10.2.1.230 from 10.2.1.22 eth0
Unicast reply from 10.2.1.230 [00:14:22:B0:5E:80] 0.833ms
Unicast reply from 10.2.1.230 [00:20:ED:79:2F:70] 0.920ms
Unicast reply from 10.2.1.230 [00:20:ED:79:2F:70] 0.644ms
Sent 2 probes (1 broadcast(s))
Received 3 response(s)
Any ideas? I must be missing something obvious...
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