Based on this initial setup:

Example: on server k5.florida, which we’re linking to k6.florida:

(change “incoming!password” and “outgoing!password”)

sudo nano /etc/inspircd/links.conf

with contents:

<link
        name="k6.florida"
        ipaddr="10.1.10.206"
        port="7000"
        allowmask="10.1.10.0/24"
        timeout="1m"
        statshidden="no"
        hidden="no"
        sendpass="outgoing!password"
        recvpass="incoming!password">

<autoconnect period="1m" server="k6.florida">

and then do this on the k6 server to allow connections from the k5 server:

<link
        name="k5.florida"
        ipaddr="10.1.10.205"
        port="7000"
        allowmask="10.1.10.0/24"
        timeout="1m"
        statshidden="no"
        hidden="no"
        sendpass="incoming!password"
        recvpass="outgoing!password">

<autoconnect period="1m" server="k5.florida">

Every time you make a change you need to restart the service:

systemctl restart inspircd.service