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I hope you can help me with a problem bothering me for long now.

I have a small home network with two routers. Both broadcast a same SSID, router/modem "1" in channel 6, router "2" in channel 1 (see network map below). The problem starts when I roam through wifi with a gadget. As you can see, I have devices connected in both routers. If I connect in router "2" wireless for example, and move to router "1", I lose network access to anything connected to router "2". The opposite apparently do not occur. The only way of solving is restarting router "2"

  • Router "1" provides access to internet, the local IP is 192.168.25.1, DHCP is on. There is reserved IP's for router "2" and the media server.
  • Router "2" have the IP 192.168.25.2, DHCP and NAT are off.
  • Media Server have a static IP reserved in router "1"

The one and only solution I find for this problem is having two completely separated wireless signals, different SSID, but that solution is unwanted since I move a lot through the house. When using the same SSID, the roaming mechanism works just fine, I can get from bedroom to living room and the access point changing works very well but, as I said I lost contact with the bedroom router "2".

The problem happens with every wireless device on the house.

I feel like I'm doing a simple mistake, but I can't see what is really the problem. I hope one of you can help me out of this.

Network map

  • How are the two routers connected to each other? If by wire, is it LAN-to-LAN or LAN-to-WAN? Is it direct or through a switch? – David Schwartz Mar 10 '16 at 19:16
  • LAN-to-LAN, directly. – J. Grimm Mar 10 '16 at 19:27
  • It sounds like you're doing everything right. It could be a router setting, or maybe your router 2 just has a poor bridging implementation (possibly in its Wifi hardware) and doesn't notice that the MAC address isn't attached to its Wifi anymore. – David Schwartz Mar 10 '16 at 19:32
  • I feared that could be a problem, a good router here in Brazil cost a full month of work... Any chance a firmware update may fix that issue, if it is in fact the router? I just noticed that the LAN and the 5Ghz have the same MAC address in router 2. Wireless 2.4GHz and WAN have different MAC. Is that normal? – J. Grimm Mar 10 '16 at 19:49
  • I found a 'interface emulator' of the Router 2, if would be useful. tp-link.com/resources/simulator/wdr4300/index.htm – J. Grimm Mar 10 '16 at 19:55
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It's quite possible that the firmware in one of your routers (it could be either one, really) is crappy and isn't updating its bridge table correctly when the MAC address of the client moves from being on that router's wireless interface to being seen on its Ethernet LAN interface (or vice-versa).

It's probably router 2 that's at fault, but rebooting it also cycles the Ethernet link for router 1, so it's still possible that router 1 is at fault, but cycling the Ethernet link clears up the problem (unless you've already found that unplugging and re-plugging that cable doesn't get it out of the bad state).

Sometimes you can help bridges (I use the term "bridges" in the expansive sense of anything that provides 802.1D bridge-like functionality, including switches and the integrated LAN/WLAN parts of home gateways and APs) update their bridge tables faster by sending multicasts or broadcasts from the MAC address of the device that moved. This usually occurs automatically due to ARP and DHCP broadcasts, but if you want to try forcing it by sending your own broadcasts/multicasts from the device seeing the issue, you could try pinging some broadcast and multicast addresses, such as 192.168.25.255 (assuming you're using a /24 subnet), 255.255.255.255, and 224.0.0.1, from the device that has lost touch with the other half of the network.

Aftermarket open-source router firmware distros might be less likely to have this bug, so updating your routers to OpenWrt/DD-WRT/Tomato/Gargoyle/etc. might clear this up for you.

  • DD-WRT update solve it! The problem roaming between the two wireless AP is gone, but the connection between the two routers is unstable. If I ping router 1 connected from router 2, it fails every two or three shots... Any idea? I followed the DD-WRT guides of configuration. – J. Grimm Mar 11 '16 at 16:48
  • Should I solve this question and start another one? – J. Grimm Mar 11 '16 at 16:48
  • @J.Grimm Yes, a separate Question seems warranted. – Spiff Mar 11 '16 at 16:49

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