Dhcpd not responding to physical hosts

Hello,

I'm trying to set up my first bare metal provisioning with foreman and
dhcpd isn't responding to queries. I've reached a dead end.

My foreman host can provision KVM virtual machines just fine. I have a
second bare metal host directly connected to interface enp5s0 which is in
bridge br0. br0 is the same bridge VMs use, so I guess that should imply
dhcp is working:
bridge name bridge id STP enabled interfaces
br0 8000.001f2965119e no enp5s0
vnet0
vnet1

I've created my physical host and told foreman to build it, and it has
correctly prepared a dhcp lease:
host zeus.lab.mydomain.com {
dynamic;
hardware ethernet 00:1f:29:ca:26:70;
fixed-address 10.0.0.11;
supersede server.filename = "pxelinux.0";
supersede server.next-server = 0a:00:00:01;
supersede host-name = "zeus.lab.mydomain.com";
}

And if I tcpdump br0 (or enp5s0) I can see that mac address doing it's
query:
21:54:22.011715 00:1f:29:ca:26:70 > Broadcast, ethertype 802.1Q (0x8100),
length 594: vlan 81, p 0, ethertype IPv4, 0.0.0.0.bootpc >
255.255.255.255.bootps: BOOTP/DHCP, Request from 00:1f:29:ca:26:70, length
548

And dhcpd is listening on all interfaces:
udp 0 0 0.0.0.0:67 0.0.0.0:*
1615/dhcpd

If I put dhcpd in foreground/debug mode, I see nothing at all. It's as if
it never sees the dhcp request.

The only weird thing I see is that "vlan 81" in tcpdump. I'm not using any
vlans. These two physical hosts are directly connected with a crossover
cable.

I've flushed iptables entirely and all is set to accept.

I don't really know how to debug further. Any suggestions?

(Apologies for top-posting)

Perhaps using a physical switch is better as while one host is down to boot
physically gets both interfaces down (especially with some card models) and
takes some time to come which is not enough.
Other hint is that listening on no traffic on the dhcpd interface is an
indication of traffic not knocking on your door. Are dumping udp traffic as
well
Just some thoughts…
Nikos

··· On Mon, May 23, 2016, 00:38 barnyard_owl_feeder wrote:

Hello,

I’m trying to set up my first bare metal provisioning with foreman and
dhcpd isn’t responding to queries. I’ve reached a dead end.

My foreman host can provision KVM virtual machines just fine. I have a
second bare metal host directly connected to interface enp5s0 which is in
bridge br0. br0 is the same bridge VMs use, so I guess that should imply
dhcp is working:
bridge name bridge id STP enabled interfaces
br0 8000.001f2965119e no enp5s0
vnet0
vnet1

I’ve created my physical host and told foreman to build it, and it has
correctly prepared a dhcp lease:
host zeus.lab.mydomain.com {
dynamic;
hardware ethernet 00:1f:29:ca:26:70;
fixed-address 10.0.0.11;
supersede server.filename = “pxelinux.0”;
supersede server.next-server = 0a:00:00:01;
supersede host-name = “zeus.lab.mydomain.com”;
}

And if I tcpdump br0 (or enp5s0) I can see that mac address doing it’s
query:
21:54:22.011715 00:1f:29:ca:26:70 > Broadcast, ethertype 802.1Q (0x8100),
length 594: vlan 81, p 0, ethertype IPv4, 0.0.0.0.bootpc >
255.255.255.255.bootps: BOOTP/DHCP, Request from 00:1f:29:ca:26:70, length
548

And dhcpd is listening on all interfaces:
udp 0 0 0.0.0.0:67 0.0.0.0:*
1615/dhcpd

If I put dhcpd in foreground/debug mode, I see nothing at all. It’s as if
it never sees the dhcp request.

The only weird thing I see is that “vlan 81” in tcpdump. I’m not using
any vlans. These two physical hosts are directly connected with a crossover
cable.

I’ve flushed iptables entirely and all is set to accept.

I don’t really know how to debug further. Any suggestions?


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Thanks for replying. I do in fact see the dhcp request - the tcpdump in my
post is taken from the foreman host, sorry if that wasn't clear.
So dhcpd is listening on the interface and tcpdump is seeing the dhcp
request broadcast but for whatever reason it's being ignored…that's my
mystery.

··· On Sunday, May 22, 2016 at 10:48:07 PM UTC+2, Nikos Zaharioudakis wrote: > > (Apologies for top-posting) > > Perhaps using a physical switch is better as while one host is down to > boot physically gets both interfaces down (especially with some card > models) and takes some time to come which is not enough. > Other hint is that listening on no traffic on the dhcpd interface is an > indication of traffic not knocking on your door. Are dumping udp traffic as > well > Just some thoughts.... > Nikos > > On Mon, May 23, 2016, 00:38 barnyard_owl_feeder > wrote: > >> Hello, >> >> I'm trying to set up my first bare metal provisioning with foreman and >> dhcpd isn't responding to queries. I've reached a dead end. >> >> My foreman host can provision KVM virtual machines just fine. I have a >> second bare metal host directly connected to interface enp5s0 which is in >> bridge br0. br0 is the same bridge VMs use, so I guess that should imply >> dhcp is working: >> bridge name bridge id STP enabled interfaces >> br0 8000.001f2965119e no enp5s0 >> vnet0 >> vnet1 >> >> I've created my physical host and told foreman to build it, and it has >> correctly prepared a dhcp lease: >> host zeus.lab.mydomain.com { >> dynamic; >> hardware ethernet 00:1f:29:ca:26:70; >> fixed-address 10.0.0.11; >> supersede server.filename = "pxelinux.0"; >> supersede server.next-server = 0a:00:00:01; >> supersede host-name = "zeus.lab.mydomain.com"; >> } >> >> And if I tcpdump br0 (or enp5s0) I can see that mac address doing it's >> query: >> 21:54:22.011715 00:1f:29:ca:26:70 > Broadcast, ethertype 802.1Q (0x8100), >> length 594: vlan 81, p 0, ethertype IPv4, 0.0.0.0.bootpc > >> 255.255.255.255.bootps: BOOTP/DHCP, Request from 00:1f:29:ca:26:70, length >> 548 >> >> And dhcpd is listening on all interfaces: >> udp 0 0 0.0.0.0:67 0.0.0.0:* >> 1615/dhcpd >> >> If I put dhcpd in foreground/debug mode, I see nothing at all. It's as if >> it never sees the dhcp request. >> >> The only weird thing I see is that "vlan 81" in tcpdump. I'm not using >> any vlans. These two physical hosts are directly connected with a crossover >> cable. >> >> I've flushed iptables entirely and all is set to accept. >> >> I don't really know how to debug further. Any suggestions? >> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Foreman users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to foreman-user...@googlegroups.com . >> To post to this group, send email to forema...@googlegroups.com >> . >> Visit this group at https://groups.google.com/group/foreman-users. >> For more options, visit https://groups.google.com/d/optout. >> >