Forward Broadcast

[hs08]

Hello,

I have subnet like this :

• My pc under vlan 100 (192.168.100.0/24)
• My NAS under vlan 150 (192.168.150.0/24)

Actually when the nas and pc located under same subnet, I can discovery the nas from my laptop using vendor utility, but can't discover when the pc and nas in different subnet. So can we forward broadcast for my pc can discover the nas in different subnet?

[Torbjørn]

Are you sure it is utilizing broadcast, and not multicast? If it is multicast you can enable multicast routing on your gateway to achieve discoverability in other subnets.

[MHM Cisco World]

try use

IP helper under the VLAN 100 toward the broadcast IP of VLAN 150 subnet 

MHM

[Torbjørn]

You will also need to enter the following config on your gateway interface for VLAN 150:

ip directed-broadcast

[MHM Cisco World]

thanks for remember me 

MHM

[hs08]

hello,

Here my config 

interface Vlan100
ip address 192.168.100.0 255.255.255.0
ip helper-address 192.168.150.255

interface Vlan150
ip address 192.168.150.0 255.255.255.0
ip directed-broadcast

But seem this is not work, the utility still can't find the NAS

[Richard Burts]

We need more information about this environment, especially what protocol the vendor utility uses to discover the server.

ip helper-address forwards certain UDP protocols. It is likely that the vendor utility uses a protocol that is not one of these. If you know the protocol (and if it is a UDP protocol) then you can use the ip forward-protocol command to enable forwarding of this protocol.

[hs08]

Hi,

If i check the apps using UDP port 9999

[Joseph W. Doherty]

BTW, might be helpful if you had a packet capture of the application traffic in both directions.

[MHM Cisco World]

ip forward-protocol udp 9999

This need also

MHM 

[hs08]

already add the command but still not discovered.

[MHM Cisco World]

I run lab for  DHCP and it work 
in NAS can you ping VLAN 100 SVI ?

MHM

[Richard Burts]

MHM correctly suggests the need to configure ip forward-protocol. The OP responds "already add" but does not tell us whether this is added under vlan 100 or 150. It needs to be under the receiving vlan (150).

[MHM Cisco World]

This command in global mode not under interface.

MHM

[Richard Burts]

MHM

You are correct. Thanks for pointing out my mistake. I was thinking of directed-broadcast, which is an interface command, and should not have indicated that for forward-protocol.