Need to Block DHCP from traveling across site-to-site TAP VPN Tunnel.

[DocUmibozu]

Thanks, but I was hoping that I simply had to add a line to the "Custom Configuration" section of the VPN Client. I am using Merlin software for its richer VPN functionality, but I have only configured through the GUI. I don't even know where to begin to find the script area let alone add/edit. I cannot seem to find it on my ASUS router. I am running 384.14_2 code

Well, you have to make some study. With the gui you won't go anywhere...

 

[Otelo]

Adding this here so I don't have to 'make study' every time I forget what I did...

0. On the client router, enable SSH access in the Administration->System->Service menu if not enabled yet, Apply changes.
1. Connect to the client router's console via ssh and check your script file directory:

admin@RT-AX56U:/# ls -la /jffs/scripts
drwxr-xr-x    2 admin    root             0 Dec  4 11:41 .
drwxr-xr-x   14 admin    root             0 Dec  4 11:15 ..

2. Create (or edit via 'vi' if it already exists!) your firewall-start script file:

admin@RT-AX56U:/# cat > /jffs/scripts/firewall-start <<EOF
#!/bin/sh
ebtables -A INPUT --in-interface tap+ --protocol ipv4 --ip-protocol udp --ip-destination-port 67:68 -j DROP
ebtables -A INPUT --in-interface tap+ --protocol ipv4 --ip-protocol udp --ip-source-port 67:68 -j DROP
ebtables -A FORWARD --out-interface tap+ --protocol ipv4 --ip-protocol udp --ip-destination-port 67:68 -j DROP
ebtables -A FORWARD --out-interface tap+ --protocol ipv4 --ip-protocol udp --ip-source-port 67:68 -j DROP
EOF
admin@RT-AX56U:/# ls -la /jffs/scripts
drwxr-xr-x    2 admin    root             0 Dec  4 11:36 .
drwxr-xr-x   14 admin    root             0 Dec  4 11:15 ..
-rw-rw-rw-    1 admin    root           438 Dec  4 11:38 firewall-start

3. Make the new file executable:

admin@RT-AX56U:/# chmod a+x /jffs/scripts/firewall-start
admin@RT-AX56U:/# ls -la /jffs/scripts
drwxr-xr-x    2 admin    root             0 Dec  4 11:36 .
drwxr-xr-x   14 admin    root             0 Dec  4 11:15 ..
-rwxrwxrwx    1 admin    root           438 Dec  4 11:38 firewall-start

4. Execute it manually the first time, or reboot router to have it loaded upon firewall start:

admin@RT-AX56U:/# sh /jffs/scripts/firewall-start