How can I configure isc-dhcp-client differently according to the chosen logical interface?

I am using debian ifupdown’s mappings, with guessnet, to connect to the “right” WiFi network wherever I am. Here is an excerpt of my /etc/network/interface: mapping wlp2s0 script /usr/sbin/guessnet-ifupdown map autofilter: true map default: wlp2s0-default iface wlp2s0-tgv-inoui inet dhcp guessnet test wireless essid _SNCF_WIFI_INOUI wpa-conf /etc/wpa_supplicant/wpa_supplicant_minimal.conf wpa-driver nl80211,wext wpa-ssid _SNCF_WIFI_INOUI wpa-key-mgmt NONE openvpn home_client I also use unbound as a local caching DNS resolver. When I am connected to the _SNCF_WIFI_INOUI WiFi network, I’d like to forward DNS requests for the sncf. zones to the resolver provided by the DHCP server, since it provides different answers from the public servers (which I need to get the information specific to the train I am traveling in). As far as I know, isc-dhcp-client uses hooks that can be called when it gets answers for the DHCP server. I guess I could write one to configure unbound as needed. But how can I ensure this only happens for the wlp2s0-tgv-inoui logical interface? Is there a way I can get the logical interface when running the hook?