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I've maintained a closed home network in my home which comprises of-

  1. D-Link Router DSL-2750u [only LAN, not WAN]
  2. Windows XP PC
  3. iPad / Nexus 7 / Android Phones x 3 / Android TV

Also I made some folders in XP shared in network, installed ES File Explorer and similar apps in all devices in (3). So from any device of (3) I can just explore shared folders.

Everything was going okay until (1) gets malfunctioned and I purchased again D-Link DSL-2750u (new firmware) now XP is not showing up in any of devices in (3) while keeping everything else same as before.

As this being closed LAN I've no antivirus or firewall in XP. The only odd thing that I noticed in new system that NMAP scan (in XP) and also Fing (in devices (3)) never show ports 445 (microsoft-ds) & 139 (netbios) in services of new router while old router always showed them.

Also I checked in XP by netstat command to find ports 445 & 139 listening.

Being a physician by profession I've no deep knowledge of these things so I blindly tried port forwarding to 445 & 139, enabling DMZ, making computer's IP as static but nothing helped.

Can you please suggest me what to do to keep open ports 445 & 139?

Sathyajith Bhat
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Maria
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  • Isn't this new firmware block a MS NetHood? – g2mk Nov 15 '15 at 13:31
  • Thanks for your reply. As every other thing is same (even router brand & model) it's only firmware doing something nasty! – Maria Nov 15 '15 at 13:47
  • I have though about new options in new firmware with NetHood disabled by default. Can you try to connect directly to XP (by cable) and check your shared network - as you write that 445 & 139 listening, so this should work and allow to confirm that it is router problem. You can disable port forwarding and DMZ but you should keep static IP's until problem will be resolved. You have very good computer networks understanding as a physician ;) – g2mk Nov 15 '15 at 15:02
  • Thanks for reply & compliment! XP is connected to the router via cable and all other devices are connected by SSID. As you suggested I've just changed dynamic to static IP for XP. Is there anything else I can try? – Maria Nov 15 '15 at 15:16
  • I suggest to start from connect your XP-machine to other PC (I'm aware that you other devices are currently connected by Wi-Fi - maybe somebody may borrow you laptop or something) directly by Ethernet cable (without switch/router) and check folder sharing this way. This computers have to be in the same network (static IP's). – g2mk Nov 15 '15 at 15:39
  • Thanks again dear dear g2mk, you've saved my ### by suggesting to connect XP to other PC. I connected another XP to router via wire and it worked. Then I wandered through this website and found another great user suggestion [link] (http://superuser.com/questions/701156/d-link-router-wifi-and-lan-segment) to turn off "Enable MultiAP Isolation" and now I've fully working LAN as before. Actually D-Link CC misled me thinking the closed ports an issue while the real issue was wired<->wireless interface via router. Thank you very much again. – Maria Nov 16 '15 at 07:37

1 Answers1

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Since you are not using the WAN port of your router, meaning you are not using it to connect to a different network, you are in fact only using its switching functionalities. So any settings that are meant to impact the actual routing facility (such as port forwarding, DMZ etc.) will have absolutely no effect on your network.

If you are using both WLAN and LAN to connect to it, you need to make sure that a bridge exists. But unless you changed anything, this will be the standard case.

You are using a lot of different devices and I hardly believe that you have a static IP setup, so your devices need to get their IP address from a DHCP server.

Most likely, you used your router as a DHCP server before and the new one might not have this set automatically. Or you might have a mix of static IP's and dynamic ones that don't mix.

Therefore I suggest the following steps:

  1. Login to your router via the supplied software or on its home page. If that doesn't work, you know you have a misconfiguration in your network so immediately go to 3.
  2. Look for "DHCP Server" somewhere in the network configuration and make sure it's enabled.
  3. Make sure that all computers and devices get their IP address dynamically. This will sometimes be underlined with the term "DHCP".
  4. If you access your shared folders from other devices via IP address and not via name, then you might have to adapt to the new address.

Hope this helps.

vic
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  • Thanks for your reply. In old router I had DHCP server enabled and all devices used to get their IP automatically. Also in new router DHCP server is enabled and all devices are getting their IP automatically. I used to access shared folders in my devices via both IP address & name like My-Android/192.168.x.y. – Maria Nov 15 '15 at 13:44
  • Yes, but the IP-Address might have changed. Actually, it is very likely that it changed. So you need to check the current IP address of your Windows PC, and verify that this is the address your other devices are using when accessing the shares. – vic Nov 15 '15 at 13:47
  • All devices scan the network and show all available devices connected to network. Also Windows's IP address is same in both cases because I've configured both routers exactly same. Like same router's IP address = 192.168.x.y. – Maria Nov 15 '15 at 13:52
  • Considering that you messed around with the router configuration, I suggest you factory reset it, and then just set the DHCP server on it, nothing else. Apart from the DHCP server component, you only use the router for layer 2 switching so it will have no impact whatsoever on your network or on your devices. The problem lies elsewhere. – vic Nov 15 '15 at 14:36
  • I've just tried factory reset for couple of times & only enabled DHCP server. But the problem is yet to be solved. Any thing else should I try? – Maria Nov 15 '15 at 15:19
  • Unless you have static IP addresses, it's impossible that your device addresses haven't changed a bit after the reset. Are you sure that you are accessing the shares in a proper way? If that all doesn't help, you could take screenshots of all relevant settings (router, windows, other devices, programs) and post them here for further analysis. – vic Nov 15 '15 at 15:26