Setup: I have two servers A and B. Server A runs dnsmasq and should assign a static IP to B (using hostname "vm03"). This IP is set in /etc/dnsmasq.conf (extract below):
domain-needed
local=/my-private-domain/
interface=eth0
interface=eth1
interface=tun0
dhcp-range=192.168.100.100,192.168.100.130
dhcp-host=vm03,192.168.100.103
Problem: This used to work just fine, but after I now upgraded server B from openSUSE 13.1 to 42.1, it doesn't work anymore = server B no longer gets assigned 192.168.100.103, but something different such as 192.160.100.124 (which is still in the general IP range I defined above).
On server A I see that dnsmasq in itself realizes that something is not right (since I also set the IP for vm03 in the /etc/hosts file of server A):
dnsmasq-dhcp: not giving name vm03 to the DHCP lease of 192.168.100.124 because the name exists in /etc/hosts with address 192.168.100.103
TcpDump: I compared the output put of "tcpdump -i eth1 -vvv -s 0 port bootps" from server B against the output from server C (still running the old openSUSE 13.1 and gets the correct IP from dnsmasq).
Old server C communicaton with A [Discover, Offer, Request ACK]. Full trace here:
lsm1:~ # tcpdump -i eth1 port 67 or port 68 -e -n
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
13:31:51.106018 52:54:00:bd:8a:6e > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:bd:8a:6e, length 300
13:31:51.106369 52:54:00:a3:7c:db > 52:54:00:bd:8a:6e, ethertype IPv4 (0x0800), length 342: 192.168.100.1.67 > 192.168.100.102.68: BOOTP/DHCP, Reply, length 300
13:31:51.106752 52:54:00:bd:8a:6e > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 354: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:bd:8a:6e, length 312
13:31:51.263232 52:54:00:a3:7c:db > 52:54:00:bd:8a:6e, ethertype IPv4 (0x0800), length 346: 192.168.100.1.67 > 192.168.100.102.68: BOOTP/DHCP, Reply, length 304
New server B communication with A [Request, NACK, Discover, Offer, Request, ACK]. Full trace here:
lsm1:~ # tcpdump -i eth1 port 67 or port 68 -e -n
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 65535 bytes
13:31:59.743740 52:54:00:be:0b:ab > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:be:0b:ab, length 300
13:31:59.744122 52:54:00:a3:7c:db > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 192.168.100.1.67 > 255.255.255.255.68: BOOTP/DHCP, Reply, length 300
13:32:00.744866 52:54:00:be:0b:ab > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:be:0b:ab, length 300
13:32:00.745244 52:54:00:a3:7c:db > 52:54:00:be:0b:ab, ethertype IPv4 (0x0800), length 342: 192.168.100.1.67 > 192.168.100.124.68: BOOTP/DHCP, Reply, length 300
13:32:00.745711 52:54:00:be:0b:ab > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 351: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 52:54:00:be:0b:ab, length 309
13:32:00.813972 52:54:00:a3:7c:db > 52:54:00:be:0b:ab, ethertype IPv4 (0x0800), length 346: 192.168.100.1.67 > 192.168.100.124.68: BOOTP/DHCP, Reply, length 304
I have no idea why the behavior changed. Is this correct or an issue with wicked? Any ideas / things to test?
Things I already checked / tried:
- The network settings on server B are unchanged (only difference: after the upgrade it is no longer managed by ifup/ifdown but wicked).
- I manually removed the lease file /var/lib/misc/dnsmasq.leases
- Restarted dnsmasq on server A and forced Ip renewls on server B via ifdown eth0 and ifup eth0
dhcp-host=11:22:33:44:55:66,fvm03,192.168.100.103?dnsmasqreleased the lease for that specific MAC address and you got a new random one then. Which is mismatching with the hostname and IP address in '/etc/hosts`.