dhcp kvm reached no server

Berokor

New Member
Jan 15, 2013
4
0
1
Hi,

i have build a KVM Server with DHCP.
The DHCP service reach all proxmox virtualserver (one node, 5 kvm virtual server) but not other real server in the network.
All KVM Server uses the bridged eth0 interface. So they must reach other real server.

Can anybody help me ?

Greetings
 
can your try this on your host:

Code:
iptables -A POSTROUTING -t mangle -p udp --dport bootpc -j CHECKSUM --checksum-fill

I have see some similar problem, with external dhcp and kvm dhcp clients.
 
iptables v1.4.8: unknown option `--checksum-fill'
Try `iptables -h' or 'iptables --help' for more information.

:~# iptables -A POSTROUTING -t mangle -p udp --dport bootpc -j CHECKSUM
iptables v1.4.8: Couldn't load target `CHECKSUM':/lib/xtables/libipt_CHECKSUM.so: cannot open shared object file: No such file or directory

Try `iptables -h' or 'iptables --help' for more information.

Greetings
 
It seem that debian squeeze iptables is too old .... (proxmox 2.X)

It's working fine on proxmox 3.0 on debian wheezy.

Maybe can you try to install iptables package from wheezy to your squeeze ? (no guarantee that it'll work)
 
can your try this on your host:

Code:
iptables -A POSTROUTING -t mangle -p udp --dport bootpc -j CHECKSUM --checksum-fill

I have see some similar problem, with external dhcp and kvm dhcp clients.
This is not an external dhcp server.

There are two physical server:
PROXMOX
-> webserver
-> mailserver
-> dhcpserver

SERVER2

the dhcp server is on a kvm virtual server ... all virtual server reach the dhcp server but the second physical server not ...
that's the problem ... all interfaces of the proxmox virtual server are bridged with eth0 of the proxmox host
 
Last edited:
This is not an external dhcp server.

There are two physical server:
PROXMOX
-> webserver
-> mailserver
-> dhcpserver

SERVER2

the dhcp server is on a kvm virtual server ... all virtual server reach the dhcp server but the second physical server not ...
that's the problem ... all interfaces of the proxmox virtual server are bridged with eth0 of the proxmox host
Hi,
i have dhcp-server running as VM and CT (on different pve-servers) and both working fine (in the whole network).

Perhaps the request don't reach the dhcp-server? Any hint's in the logfile?

Udo
 
This is not an external dhcp server.

There are two physical server:
PROXMOX
-> webserver
-> mailserver
-> dhcpserver

SERVER2

the dhcp server is on a kvm virtual server ... all virtual server reach the dhcp server but the second physical server not ...
that's the problem ... all interfaces of the proxmox virtual server are bridged with eth0 of the proxmox host

so your kvm guest hosting the dhcp server on server1, is external from server2 right ?

The main problem (for my case) related to checksum offload when going through eth0.
I think it should be possible to play with checksum offload with "ethtool -K eth0", but I don't remember exactly how to tune it.

also as alternative, you can try to use e1000 interface in your kvm guest dhcp server.
 

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