Question: I am running a squid proxy server, and when I need to add new IPs to the allow list, I have just been doing for example:

`acl internal src 86.139.20.58`

However, I now want to allow a client that only has an IPV6 address.

I've tried

`acl internal src [the address]`

but I still get access denied errors from squid. 

What do I need to do? Many thanks!

Answer: 
[acl directive](http://www.squid-cache.org/Doc/config/acl/) does not surround addresses with [], so omit those.

For example:

```
acl six src 2001:db8:46e2:c::/64

```

For v6, consider supplying a mask to match the subnet. Temporary addresses result in a client not having the same IP for long. Could match more than one host, but expect a /64 to be on the same LAN.
For reasons I don't understand, it seems to be wanting an IPV4 address. I enabled acl logging as per <https://wiki.squid-cache.org/SquidFaq/SquidAcl#I_set_up_my_access_controls.2C_but_they_don.27t_work.21__why.3F> with

`debug_options ALL,1 33,2 28,9`

in squid.conf. From that I could see that it was trying to find an IPV4 address, even though when I go to websites like <https://whatismyipaddress.com/>, I only get an IPV6 address and the IPV4 address is unresolved.

Correction - I now seem to get both an IPV6 and an IPV4 address from that website. I didn't earlier. 

I don't understand why putting in the IPV6 doesn't work in my squid.conf, but I can get by now with the IPV4.