Hello, I have two gateways (one is backup adsl and the other is wifi ISP, which is faster). I'd like to configure some MAC adresses (such as voip phone) to use the adsl gateway as default, becasue it is more reliable.

This is my /etc/config/dhcp on wifi router running openwrt:

config dnsmasq
        option domainneeded '1'
        option boguspriv '1'
        option filterwin2k '0'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option local '/lan/'
        option domain 'lan'
        option expandhosts '1'
        option nonegcache '0'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp.leases'
        option resolvfile '/tmp/resolv.conf.auto'

config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '100'
        option leasetime '12h'
        option ignore '0'
        option dhcp_option '3,10.0.0.1 6,88.86.108.7'

config host
        option ip '10.0.0.5'
        option mac '11:AA:BB:CC:DD:EE'
        option dhcp_option '3,10.0.0.254 6,208.67.222.222'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

MAC address '11:AA:BB:CC:DD:EE' gets the ip 10.0.0.5, but it does not receive the gateway 10.0.0.254 and dns 208.67.222.222, it gets the gateway configured previously in 'lan'. How can I assign different gateways and dns servers to different comuters? Thank you.

(Last edited by nozombian on 6 Feb 2013, 11:54)

First desperate bump

Sounds like you need more than DHCP to do this. DHCP can be used to indicate that a given connected device should route its packets to a specific interface on the router, but then the router decides which gateway to send those packets to. You would need to "tell" the OpenWRT box to route the packets received on interface1 to gateway1 and those received on interface2 to gateway2, as well as telling the attached device to route its traffic to interface2 instead of interface1. You'd likely also need another NAT to handle the gateway2 traffic as well.

Thank you for reply, I'm using openwrt as a bridge with wifi AP and it is running a dhcp daemon, so it is only assigning addresses, but it is not a gateway at all, so most of the traffic is not going over this openwrt router. One my gateway is mikrotik router, which I don't have root access to, because it is leased from isp with the service, and the other gateway is adsl modem, both gateways are connected to a switch, where is also my openwrt connected, but it is located elswehere in different building, where I need wifi.

If I set IP/mask/gatway manually on device, everything is working fine, but some devices I have in network do not support manual IP addressing, they work only with dhcp.

From a quick read of the dnsmasq man page.

-G, --dhcp-host=[<hwaddr>][,id:<client_id>|*][,set:<tag>][,<ipaddr>][,<hostname>][,<lease_time>][,ignore]

Maybe I'm missing something, but I don't see an option to directly specify by-host parameters other than the IP address.

The "tag" feature looks like it might be what you need

-O, --dhcp-option=[tag:<tag>,[tag:<tag>,]][encap:<opt>,][vi-encap:<enterprise>,][vendor:[<vendor-class>],][<opt>|option:<opt-name>|option6:<opt>|option6:<opt-name>],[<value>[,<value>]]

-F, --dhcp-range=[tag:<tag>[,tag:<tag>],][set:<tag],]<start-addr>[,<end-addr>][,<mode>][,<netmask>[,<broadcast>]][,<lease time>]
-F, --dhcp-range=[tag:<tag>[,tag:<tag>],][set:<tag],]<start-IPv6addr>[,<end-IPv6addr>][,<mode>][,<prefix-len>][,<lease time>] 

You may get some clues in package/dnsmasq/files/dnsmasq.init on how set/tag could be added to the configuration file.

(Last edited by jeffster on 14 Feb 2013, 21:08)

Uh, sounds a bit complicated. But thank you very much for your help, especially with pointing out the tag flag, I will try to study that and what it could do, but it won't be supported by uci for sure

(Last edited by nozombian on 15 Feb 2013, 10:27)