Router - modem communication issue

Hello,

I've been using serviio in the past weeks for streaming movies/pictures to my TV and I really love your program.

Recently I have plugged my desktop (streaming machine) directly to the modem - Cisco EPC3925 - and my desktop does not detected any other devices anymore. I used to have all my devices (laptops, desktop, TV etc.) connected (plugged or WiFi) to Negear WNDR3700 router and everything worked flawlessly then.

Also, I can't connect to the modem's website via desktop. I can access it from my laptop. (even though it is connected to the router via wifi)

I have a static IP so I had to set up IP adress, subnet mask, default gateway and dns servers. Afair I had to use other mask than the one technician gave me to make it work - maybe it is the reason?

So the question is: how do I make all the devices plugged to the router visible for my desktop, which is plugged to the modem? Is is possible?

Why not plug it back? Because router caused some strange delay in World of Warcraft.

Hope everything is understandable and I'll get some help.

[DenyAll]

If I understand it correctly, the Cisco has two LAN ports connected - one to your fixed PC (the one with Serviio on it) and one to the Netgear router (connected to the WAN port on the Netgear). The Netgear then has all other devices connected to it (either via cable or via wireless). Is this correct?

This configuration should be possible, but it also requires a fair bit of playing around to achieve it (provided that your router allows the level of configuration required - the Netgear hasn't got many "advanced" options). Firstly, its best if all devices have the same range of IP addresses - what IP addresses/masks have been assigned to devices? They should all be getting their IP addresses assigned from the same DHCP (the Cisco) if possible, or if static, everything (including the addresses of the routers) should be in the same range (eg. 192.168.0.xxx).

And what I suspect is the issue - you then need to ensure that all devices are on the same broadcast domain - DLNA/UPNP uses broadcasts to advertise the presence of devices. I suspect the Netgear in this configuration is not forwarding broadcast packets, from what it sees as being from the WAN, to connected devices. This config effectively creates two broadcast domains - one on the LAN side of the Netgear, and one on the LAN side of the Cisco, and unless you configure it, broadcast packets from one will not be broadcast on the other.

The problem you will have is that I [have the 3700 and] cannot see any options to turn this on on the 3700 - your firmware may have it though (look for IGMP options). Other than that you may want to try turning off the protection (firewalls/port scan/DoS protection) to see if that allows these broadcasts through.

An alternative is that you connect from a spare LAN port (if you have one) on the Netgear to the LAN port on the Cisco (ie. do not use the WAN port on the Netgear). This effectively turns the Netgear into a switch rather than a router, but check internet connectivity from all devices after doing so.

Why not plug it back? Because router caused some strange delay in World of Warcraft.

Hmm, probably because of the router (Netgear) via router (the Cisco is actually a router) connection to the net, likely with two NAT's active. Did you ever try leaving the fixed PC connected to the Netgear, and setting the Cisco to operate either as in Modem only mode or Bridge mode (depending on what it supports).

[atc98092]

Yep, the dual router connection was causing your computer and the rest of your network to be on separate subnets. The end result is that nothing on one can see the other.

As you discovered, turning the second router into a switch removes the block between the networks. However, make sure the second router (the Netgear) has DHCP turned off. As DenyAll mentioned, all IP addresses should be assigned from just one device.

Also as he mentioned, it is possible to work the way you had it originally, but it requires very specific settings, and quite a bit of knowledge about networking and IP routing. Best to not mess with it.