[Users] Running DHCP on VPS, ( on a router.. )

[Kirill Korotaev]

Dariush,

can you please add -e option to tcpdump, so that we could check MAC in packets?
and tell me plz MAC addresses of HN, veth inside VE and your DHCP client.

Thanks,
Kirill


Dariush Pietrzak wrote:
>>DHCP server should work fine with veth bridged to host eth0 interface.
>>Can you reproduce your issue when server doesn't reply?
> 
>  it looks like this:
> 
> HN: tcpdump -n -i eth0.107
> 08:16:19.401880 00:1b:d4:7e:76:2a > 01:00:0c:cc:cc:cd SNAP Unnumbered, ui, Flags [Command], length 50
> 08:16:21.154240 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1b:d5:2c:bf:38, length 308
> 08:16:21.185096 IP 192.168.8.254.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
> 08:16:21.187344 arp who-has 192.168.9.254 tell 192.168.9.97
> 
> 
> HN: tcpdump -n -i br107
> 08:16:19.401880 00:1b:d4:7e:76:2a > 01:00:0c:cc:cc:cd SNAP Unnumbered, ui, Flags [Command], length 50
> 08:16:21.154240 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1b:d5:2c:bf:38, length 308
> 08:16:21.185096 IP 192.168.8.254.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
> 08:16:21.187344 arp who-has 192.168.9.254 tell 192.168.9.97
> 
> and finally, from inside the vps:
> VPS: tcpdump -n -i eth0
> 08:16:19.401886 00:1b:d4:7e:76:2a > 01:00:0c:cc:cc:cd SNAP Unnumbered, ui, Flags [Command], length 50
> 08:16:21.185110 IP 192.168.8.254.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
> 08:16:21.187356 arp who-has 192.168.9.254 tell 192.168.9.97
> 08:16:21.188600 arp who-has 192.168.8.1 tell 192.168.9.97
> 
>  as you can see, broadcast request from dhcp client is missing, but strangely enough, the reply
> is clearly visible.
> 
>  I also tried doing something like this to verify the software inside VPS: I chroot to ..../vz/private/107/
> and then launch the dhcpd against br107, and then it works as expected.
>