Ask Your Question
0

VM on controller node cannot get ip from dhcp

asked 2014-02-20 20:21:35 -0500

laocius gravatar image

updated 2014-02-25 01:46:32 -0500

I have two nodes installed. Node 1 function as controller node, network node and compute node. Node 2 works only as a compute node.

I am using neutron linuxbridge plugin for the networking. Now if a VM is scheduled on Node2, everything's OK. While if a VM is sheduled on Node1, it always fails to get IP from dhcp.

Starting network... udhcpc (v1.18.5) started Sending discover... Sending discover... Sending discover... No lease, failing

It seems dhcp reply cannot reach the target VM.

Here's output of tcpdump

[root@controller 088f3c8d-ecc6-441a-be76-24d00247492b]# tcpdump -i any |grep -i dhcp

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on any, link-type LINUX_SLL (Linux cooked), capture size 65535 bytes

10:14:15.497874 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:15.497890 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:15.497894 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:15.497898 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280 10:14:15.497901 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:15.497874 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:15.498994 IP 10.147.1.3.bootps > 10.147.1.4.bootpc: BOOTP/DHCP, Reply, length 325

10:14:15.498998 IP 10.147.1.3.bootps > 10.147.1.4.bootpc: BOOTP/DHCP, Reply, length 325

10:14:18.503070 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:18.503083 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:18.503087 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:18.503091 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280

10:14:18.503094 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from fa:16:3e:f1:96:f3 (oui Unknown), length 280 10:14:18.503070 IP 0.0.0.0.bootpc > 255.255.255.255.bootps: BOOTP/DHCP, Request from ... (more)

edit retag flag offensive close merge delete

2 answers

Sort by ยป oldest newest most voted
0

answered 2014-02-25 04:04:18 -0500

Sifty gravatar image

Run this on the controller node - before starting openstack-nova services. It fixes DHCP resolution on the same controller host.

iptables -A POSTROUTING -t mangle -p udp --dport 68 -j CHECKSUM --checksum-fill

https://ask.openstack.org/en/question...

edit flag offensive delete link more

Comments

I tried that, it doesn't work. The problem is dnsmasq-dhcp can receive DHCPDISCOVER but fail to receive DHCPREQUEST.

laocius gravatar imagelaocius ( 2014-02-27 03:28:25 -0500 )edit
0

answered 2014-02-21 01:24:23 -0500

laocius gravatar image

I also ran tcpdump on the tap device that was attached to my VM and found that DHCP reply can reach the tap device but not my VM.

edit flag offensive delete link more

Your Answer

Please start posting anonymously - your entry will be published after you log in or create a new account.

Add Answer

Get to know Ask OpenStack

Resources for moderators

Question Tools

1 follower

Stats

Asked: 2014-02-20 20:21:35 -0500

Seen: 1,380 times

Last updated: Feb 25 '14