<div dir="ltr"><div><div><div><div>Hello everybody,<br><br></div>I am running into an issue for the second time where a new virtual machine is receiving concurrent leases for a single network adapter. This machine has two interfaces - eth0 and eth1 - and receives two leases on eth0, and one lease on eth1.<br>
<br>If I restart the secondary DHCP server, and then restart networking on my
client, the client no longer receives the secondary eth0 lease. This is how I resolved the original client's issue with the same problem, but has just happened again to another new client yesterday.<br><br></div><div>
My architecture looks like this: Two CentOS 6.3 4.1.1-P1 DHCP servers, each on their on subnet. My cisco gateways are configured with ip helper-addresses to send DHCP traffic to both servers, and each DHCP server is configured as a failover peer.<br>
<br>interface Vlan123<br> ip address 172.21.52.129 255.255.255.192<br> ip helper-address 172.21.35.18<br> ip helper-address 172.21.35.26<br>!<br></div><div><br></div><div>35.18 is the primary, 35.26 is the secondary.<br></div>
<div><br></div>When bringing up dhclient on my client, eth0 gets two IP addresses:<br><br>2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000<br> link/ether 00:50:56:a8:50:e3 brd ff:ff:ff:ff:ff:ff<br>
inet <a href="http://172.21.52.167/26">172.21.52.167/26</a> brd 172.21.52.191 scope global eth0<br> inet <a href="http://172.21.52.145/26">172.21.52.145/26</a> brd 172.21.52.191 scope global secondary eth0<br> inet6 fe80::250:56ff:fea8:50e3/64 scope link <br>
valid_lft forever preferred_lft forever<br>3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000<br> link/ether 00:50:56:a8:6e:db brd ff:ff:ff:ff:ff:ff<br> inet <a href="http://172.21.52.69/26">172.21.52.69/26</a> brd 172.21.52.127 scope global eth1<br>
inet6 fe80::250:56ff:fea8:6edb/64 scope link <br> valid_lft forever preferred_lft forever<br><br></div>If I restart the DHCP service on the secondary server, and then restart networking on the DHCP client, the secondary eth0 lease is no longer handed out.<br>
<br>Has anyone run into this kind of issue before? I haven't been able to find any reports of this same issue.<br><br></div>If you need any other information to troubleshoot this, please let me know!<br><br>Thanks,<br>
Kyle<br></div>