SQUID Proxy - Local Cache as the local storage (Mikrotik & Linux)

With this tutorial you should be able to use the Local Cache as the local storage and thus to reduce data traffic and speed up the content loading from the Internet. The solution is using the Linux Proxy (SQUID) and using its cache for saving frequently requested files from the Global CDN (Content Delivery Network). The Linux Proxy (SQUID) should be in front of your wireless infrastructure. The essence of this solution is to use local resources to reduce data traffic and internet connectivity.

The solution consists of two parts.

Linux SQUID proxy server in transparent mode utilized as a parent proxy
Mikrotik used for routing queries to the parent proxy cache

SQUID

Use common Linux distribution (e.g. CentOS) and install the SQUID application in it. In the topology SQUID must be located exactly in the main segment so that its IP addressing is in conformity with the Mikrotik addressing on the interface that is used towards Internet. This is important for the Mikrotik's communication with the Master parent proxy server.

SQUID configuration is simple and uses SQUID in the transparent mode. See the example of the configuration file:

#
# Recommended minimum configuration:
#
acl manager proto cache_object
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
 
 
# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
acl localnet src 10.0.0.0/8     # RFC1918 possible internal network
acl localnet src 172.16.0.0/12  # RFC1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
acl localnet src fc00::/7       # RFC 4193 local private network range
acl localnet src fe80::/10      # RFC 4291 link-local (directly plugged) machines
acl SSL_ports port 443
acl Safe_ports port 80          # http
acl Safe_ports port 21          # ftp
acl Safe_ports port 443         # https
acl Safe_ports port 70          # gopher
acl Safe_ports port 210         # wais
acl Safe_ports port 1025-65535  # unregistered ports
acl Safe_ports port 280         # http-mgmt
acl Safe_ports port 488         # gss-http
acl Safe_ports port 591         # filemaker
acl Safe_ports port 777         # multiling http
acl CONNECT method CONNECT
#
# Recommended minimum Access Permission configuration:
#
# Only allow cachemgr access from localhost
http_access allow manager localhost
http_access deny manager
 
 
# Deny requests to certain unsafe ports
http_access deny !Safe_ports
 
 
# Deny CONNECT to other than secure SSL ports
http_access deny CONNECT !SSL_ports
 
 
# We strongly recommend the following be uncommented to protect innocent
# web applications running on the proxy server who think the only
# one who can access services on "localhost" is a local user
 
 
#http_access deny to_localhost
#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#
# Example rule allowing access from your local networks.
# Adapt localnet in the ACL section to list your (internal) IP networks
# from where browsing should be allowed
http_access allow localnet
http_access allow localhost
 
# And finally deny all other access to this proxy
#http_access deny all
 
 
# Squid normally listens to port 3128
http_port 3128 transparent
 
 
# We recommend you to use at least the following line.
hierarchy_stoplist cgi-bin ?
 
 
# Uncomment and adjust the following to add a disk cache directory.
#cache_dir ufs /var/spool/squid 100 16 256
cache_dir ufs /var/spool/squid 100 16 256
 
 
# Leave coredumps in the first cache dir
coredump_dir /var/spool/squid
# Add any of your own refresh_pattern entries above these.
refresh_pattern ^ftp:           1440    20%     10080
refresh_pattern ^gopher:        1440    0%      1440
refresh_pattern -i (/cgi-bin/|\?) 0     0%      0
refresh_pattern .               0       20%     4320
visible_hostname proxy_hotspot.socifi.com

The most important thing is to switch to the transparent mode.

http_port 3128 transparent

Mikrotik

Simply adjust settings in your already configured Mikrotik Hotspot in the tab WebProxy (/ip/web proxy). Proceed as follows:

On the General tab, please set successively:

enable - tick on
Src. Address - delete the IPv6 address set by default and replace it with the IP address that is used by Mikrotik in the segment where the SQUID is located. (parent proxy server)
Port - leave default 8080
Anonymous - tick on
Parent Proxy - IP address of the master SQUID
Parent Proxy Port - 3128

Other options are not necessary to be set, they will not be used.

In sub-tab Cache add the following option to prevent local caching on Mikrotik to avoid plugging its memory:

add a new rule without attributes. The only attribute to change is the "Action" set as "Deny"
In the sub-tab Direct define domain (URL) for which you want to use the parent proxy. Other addresses will be inquired directly from the Internet. Add the following rules in the sequence they are listed (that is important!) With these settings (one rule per line):

Dst.Host = connect.socifi.com ; Action = Allow
Dst.Host = *.socifi.com ; Action = Deny
Dst.Host = *.cloudfront.net ; Action = Deny
Dst.Host = *.amazonaws.com ; Action = Deny
Dst.Host = ; Action= Allow

Conclusion

It is possible to alternate the setting, use the administration above as the introduction into the SQUID solution