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Hello! I have 2 routers. The primary router (which is also a modem. from now on I"ll call it A) and the secondary router (B from now on), which is connected to the primary router via 10 meters Ethernet cable (from A's LAN to B's LAN). The DHCP server is running only on A, and the IP of B is outside the DHCP range. (I think it is called "piggy backing".)
For some reason, when I run a server on a device which is connected to A, I can access the server only from a device that is connected to router B. For example, when I run an SSH server on my Linux machine which is connected to A, I have to connect to B to connect to it. Otherwise, the client will throw me a connenction error.
What am I doing wrong? Thanks
ohad987
Posted 2015-07-11T19:27:29.847
Reputation: 11
Can you at least ping the device on A when you are on A? Isn't the A firewall blocking communication between ports? – tikend – 2015-07-11T19:45:37.500
Can you tell us the IP address and subnet mask of each router? – Larssend – 2015-07-11T22:20:53.467
@tikend When I ping from my Windows machine to my Android (both connected to A) the ping request time out. I have no idea if there's a firewall- but I didn't configured one and I'm pretty sure there is no firewall. Is there any way to check it out? Thanks – ohad987 – 2015-07-11T22:38:15.380
@geewee Sure. The IP of A: 10.0.0.138. The IP of B: 10.0.0.32. A's DHCP server range is 10.0.0.1-24 by the way. I'm not sure how to get the router's subnet mask, I don't see any option in the router CP. How can I do it? Thanks – ohad987 – 2015-07-11T22:39:35.427
Should be on the same LAN interface config page. – Larssend – 2015-07-11T23:03:54.563
@geewee Both routers' subnet mask is 255.255.255.0 – ohad987 – 2015-07-11T23:21:31.910
Ok, my mistake, still doesn't work. Any advice? – ohad987 – 2015-07-12T06:42:24.117
Based on your information, everything seems to be in order. What happens if you ping the server connected to Router A from a host that's also connected to Router A? Also, do any of your routers have VLAN support? – Larssend – 2015-07-12T06:51:19.083
@geewee A supports VLAN. When I ping from A to A the ping return timeout exception. – ohad987 – 2015-07-12T06:53:43.517
Seems like there's a VLAN (mis)configuration. Try turning off VLAN completely, or group every LAN port on Router A into one VLAN. – Larssend – 2015-07-12T06:56:31.090
Ok, I'll try it out. Another thing that I found out is that if I ping from A (there's a ping option in the CP) to a device which is connected to A everything works fine. @geewee – ohad987 – 2015-07-12T07:04:27.253
This is my VLAN table. Is there anything wrong there? http://i.imgur.com/2IsqlMj.png
– ohad987 – 2015-07-12T07:30:02.120