I have a DHCP server (Linux, IPCop, dnsmasq) running on my default gateway server I have a VPN endpoint on another server in the network ( Is it possible to configure the DHCP server so it sends not only the default gateway but also routing information for the VPN (192.168.1.*) to DHCP clients when they request an IP address? The DHCP clients run Windows and Linux.

I tried to find something in the official documentation (http://www.ipcop.org/2.0.0/en/admin/html/custom-dnsmasq-local.html) but failed. The existence of RFC3442 indicates that it might be possible somehow.


1 Answer 1


This can be done by adding the following lines to dhcpd.conf:

option rfc3442-classless-static-routes code 121 = array of integer 8;
option rfc3442-classless-static-routes 24, 192, 168, 1, 192, 168, 0, 4;
option ms-classless-static-routes code 249 = array of integer 8;
option ms-classless-static-routes 24, 192, 168, 1, 192, 168, 0, 4;

This distributes a route entry for network using the gateway

The meaning of the bytes is (in brackets the value from the example above):

WW, D1, D2, D3, R1, R2, R3, R4
WW      = destination network mask width (24)
D1..D3  = destination network address (192.168.1.*)
R1..R4  = router address (

Note: The number of D1..DN bytes varies depending on the network mask. See RFC3442 for details.


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