WAN2 facing DHCP is not working

[suar88]

Hi,

My fortigate wan2 is facing another router with DHCP and fortigate shows failed status. how to configure wan2 to receive IP from DHCP?

[Iescudero]

Hi there!

IN FortiOs 5.2 you have to go to system>Network>Interfaces>double click in WAN2 interface>

Select in addressing mode DHCP>Check in retrieve default gateway from server>Check in Override internal DNS>Click in OK/Accept the changes.

though CLI:

config system interface

edit "wan2"

set mode dhcp

 set defaultgw enable

 set dns-server-override enable

set status up

next

end

If you need more detailed configuration, please explain a little bit more about your scenario, for instance wich model of Fortigate are you using, wich FortiOs Version, Is this a Internet connection? you have multiple ISP?

Hope it helps.

Cya!

[suar88]

Hi,

I tried the settings via CLI but still not working. it still says failed. last week we did the same and it works after an hour of the network guy configuring it. not really sure why setting this as dhcp is too complicated. are there other things I need to do? 

[Iescudero]

suar88 wrote:

Hi,

I tried the settings via CLI but still not working. it still says failed...are there other things I need to do? 

No, with this would be enough. Some years ago I had the same problem. I remember that I disabled the interface and enabled again and started working. I think it has some to do with the router attached.

to have some more data, you should do an sniff in this interface.

CLI:

diagnose sniffer packet wan2

and tell us what do you see.

[suar88]

i keep getting this > 802.1w, rapid stp, flags then i also see 802..1Q vlan#16 P7

[suar88]

i also see thisbelow

0.0.0.068 > 255.255.255.255.67: udp 548

192.168.1.1.67 > 255.255.255.255.68: udp 300

[suar88]

yes for internet with multiple ISP.

[Toshi_Esumi]

If wan2 is directly connected to the ISPs handoff device, it's likely VLAN tagged (vlan 16). Check with your ISP then if that's the case, you need to configure a vlan interface on wan2 then configure DHCP on the interface. You must have eliminated ISP-provided router which was, or was supposed to be, handling the vlan.

[suar88]

no ignore the vlan as i change the port. the connection is like this ISP > linksys router > Cisco switch vlan > fiber optic > cisco switch > fortinet. 

i change port and i no longer see the vlan message only below

802.1w,

192.168.1.1.67 > 255.255.255.68 udp

0.0.0.0.68 > 255.255.255.255.67 udp

[Toshi_Esumi]

So it's supposed to be getting a DHCP IP from the linksys router instead of from the ISP?