IP forwarding when running a web server

[jesperevertsson]

Hi, I just have a quick question regarding the _IP_forward variable in MQX. As default this is set to false, but in the http server example it's set to true. I just wanted to know what the reason for this is and what the effects are. The reason I'm asking is beacuse when we run a program to monitor SNMP it says that all our products that have embedded web servers are routers, since the snmp node ipForwarding returns 1. It's not a big problem by any means, but it can be a bit missleading for our customers if our products gets mistaken for routers by  some SNMP monitoring programs. But would there be any negative effects if we didn't set _IP_forward to true when using a https server?

[danielchen]

Just add to Craig's good comments, let me give an example here, let's say you have two NICs, one (NIC1) is at address 192.168.2.1/24, and the other (NIC2) is 192.168.3.1/24.  If forwarding is enabled, and a packet comes in on NIC1 with a "destination address" of 192.168.3.9, your divices will resend that packet out of the NIC2.  If forwarding is not enabled, this packet will be discarded.

Regards

Daniel

[EAI · Accepted solution]

Jesper;

_IP_forward is set to true when you want RTCS to forward packets between multiple interfaces (act like a router between subnets). It only makes sense to enable this if there are multiple interfaces.

Craig