DHCP server assigning wrong IP due to Sky Q set top box

[minitux]

Hi,

I have a couple of VLANs set. One of these, on the 192.168.40.1 subnet, is assigned to my Sky Q set top box. This subnet is assigned a "guest" behaviour so it cannot communicate with other subnets but it can go on the internet. Downstream of opensense is a cisco sg300 VLAN capable switch. The Sky Q is plugged into port 4.

The i have a few temperature sensors that log in via wireless over another subnet 192.168.1.1. DHCP server assigns static IP (on the subnet 192.168.1.1) base on mac address to these sensors. When the Sky Q is plugged in, the DHCP server assigns incorrect IP from the 192.168.40.1 subnet instead of the 192.168.1.1 subnet. See below.

Dec 15 02:17:45   dhcpd      DHCPACK on 192.168.1.61 to 60:01:xx:xx:xx:xx via em2
Dec 15 02:17:45   dhcpd      DHCPREQUEST for 192.168.1.61 (192.168.1.1) from 60:01:xx:xx:xx:xx via em2
Dec 15 02:17:45   dhcpd      DHCPOFFER on 192.168.1.61 to 60:01:xx:xx:xx:xx via em2
Dec 15 02:07:36   dhcpd      DHCPNAK on 192.168.1.61 to 60:01:xx:xx:xx:xx via em3.40
Dec 15 02:07:36   dhcpd      DHCPREQUEST for 192.168.1.61 (192.168.1.1) from 60:01:xx:xx:xx:xx via em3.40: wrong network.
Dec 15 02:07:36   dhcpd      DHCPACK on 192.168.1.61 to 60:01:xx:xx:xx:xx via em2
Dec 15 02:07:36   dhcpd      DHCPREQUEST for 192.168.1.61 (192.168.1.1) from 60:01:xx:xx:xx:xx via em2

is it as if the SkyQ was acting as an access point as its the only wireless unit active on the em3.40 subnet. Is this possible? Do you not find this strange?

Cheers

[bartjsmit]

Packet traces on specific interfaces trump amalgamated logs. Check what is going on with Interfaces -> Diagnostics -> Packet Capture. Wireshark is your friend.

Bart...

[marjohn56]

I also use Sky Q and a Sky Q mini on my IoT VLAN, no issues at all, 16 devices in total on the IoT VLAN, all of them with statically assigned dhcp addresses. Either your firewall is allowing all traffic to travel between the two vlans or the Cisco switch is incorrectly set.