1. open `~/.ssh/config` and add

        Host socksproxy
            HostName 1.2.3.4
            BatchMode yes
            RequestTTY no
            Compression yes
            DynamicForward localhost:8123
            IdentityFile ~/.ssh/proxy_rsa
            User username

2. open `~/.bashrc` and add

        alias socksproxy='/usr/bin/firefox -no-remote -P socksproxy && ssh -nkN socksproxy'

3. open firefox, in the url bar type `about:profiles` and create a new profile called `socksproxy`
load socksproxy profile
open Preferences -> Network Settings -> Manual proxy configuration -> SOCKS Host set to localhost and Port to 8123,
under `No proxy for` add `localhost, 127.0.0.1`. Activate `Proxy DNS when using SOCKS v5` and click ok.

4. open terminal and type

        $ socksproxy

5. wait until firefox profile is open and check your ip address. It should be the ip address of the proxy server.

Warning: May show warning `Firefox is already running`. Just click ok and refresh socksproxy profile of firefox.

For chrome browser to use proxy server open `~/.bashrc` and add

        chromeproxy() { /usr/bin/google-chrome --proxy-server="socks5://localhost:8123" --host-resolver-rules="MAP * ~NOTFOUND , EXCLUDE localhost" "$@" & }

        alias socksproxychrome='chromeproxy && ssh -nkN socksproxy'