Is there any better way to iterate two list to find relation between items in python?

I mock a ip list and a subnet dict as input:

# ip address list
ip_list = [
'192.168.1.151', '192.168.10.191', '192.168.6.127', 
'192.168.2.227', '192.168.2.5', '192.168.3.237', 
'192.168.6.188', '192.168.7.209', '192.168.9.10',
# Edited: add some /28, /16 case
'192.168.12.39', '192.168.12.58', '10.63.11.1', '10.63.102.69',
]

# subnet dict
netsets = {
'192.168.1.0/24': 'subnet-A',     # {subnet: subnet's name} 
'192.168.10.0/24': 'subnet-B', 
'192.168.2.0/24': 'subnet-C', 
'192.168.3.0/24': 'subnet-C',
'192.168.6.0/24': 'subnet-D', 
'192.168.7.0/24': 'subnet-D', 
'192.168.9.0/24': 'subnet-E',
# Edited: add some /28, /16 case
'192.168.12.32/28': 'subnet-F',
'192.168.12.48/28': 'subnet-G',
'10.63.0.0/16': 'subnet-I',
}

and then each ip address in ip_list need to find the name of subnet.

We assume that each ip address can find the corresponding subnet in netsets.

Ouput like this:

192.168.1.151   subnet-A
192.168.10.191  subnet-B
192.168.6.127   subnet-D
192.168.2.227   subnet-C
192.168.2.5     subnet-C
192.168.3.237   subnet-C
192.168.6.188   subnet-D
192.168.7.209   subnet-D
192.168.9.10    subnet-E
# add some /28, /16 case
192.168.12.39   subnet-F
192.168.12.58   subnet-G
10.63.11.1      subnet-I
10.63.102.69    subnet-I

I use netaddr to calculate CIDR, here is my code:

from netaddr import IPAddress, IPNetwork

def netaddr_test(ips, netsets):
    for ip in ips:
        for subnet, name in netsets.iteritems():
            if IPAddress(ip) in IPNetwork(subnet):
                print ip, '\t',  name
                break

netaddr_test(ip_list, netsets)

But this code is too too too slow, it iterate too much. the complexity of time is O(n**2).

Once we have tens of thousands of ip to iterate, this code cost too much time.

Is there any better way to solve this problem?