Two computers can't access each other on network but a third computercan access both of them

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

On Thu, 25 Jun 2015 00:43:31 -0400, Bobbyville
wrote:

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Address clash?


--
Steve Hayes from Tshwane, South Africa
Web: http://www.khanya.org.za/stevesig.htm
Blog: http://khanya.wordpress.com
E-mail - see web page, or parse: shayes at dunelm full stop org full stop uk

In article ,
, Bobbyville says...

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Check they're all in the same workgroup (suggested name: WORKGROUP)

Otherwise, I fear it's the famous Master Browser Election issue (which I
don't think it is, because you can't ping the PC's).

Also check in Control Panel, Network & Sharing Center, Advanced Sharing
settings - that Network Discovery and File and printer sharing is turned
on on all the PC's.

--
Duncan.

On 6/25/2015 12:43 AM, Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

As said address clash could be a cause.

However some times Windows 8 can be snooty, and some time discriminates
against some computers by not acknowledging they exist.

If by Communicate you mean share drives, determine the LAN address of
the computer that will not talk. On the Windows 8 computer go to the
Map Drives, and when it asked the location of the drive you wish to
connect add the numeric address of that drive. (ie, 192.168.01)

This is the only way I could get my windows 8.1 computers to find my
hard wired print server.

On 25/06/2015 05:43, Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and Lappy
are both running Windows 8.1, and Desktop is running Windows 7. Before I
got the new router, all these computes could share files and remote
desktop just fine with each other. Now Desktop and media-center can't
communicate at all with each other (they can't ping each other, remote
desktop, or share files) but Lappy can communicate with both of these
computers just fine. Any ideas?

Have you manually set the IP address for any of these computers - or are
they all automatic via DHCP? What are the current IP addresses and
subnet masks for each of your 3 computers?
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

On Thu, 25 Jun 2015 08:38:15 -0400, Wolf K wrote:

On 2015-06-25 12:43 AM, Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Set up a Homegroup/Workgroup network. I would try this even if I'd
already set up a network prior to getting the new router. NB that each
machine has automatically connected to the router, but that does not
mean an automatic network setup.

Routers do what their name states: they route traffic. It's up to the
computer(s) to accept or reject that traffic. For some reason, two of
the computers reject/ignore each other's share requests.

Within the context of a LAN, routers don't route. They are only (mostly) a
layer 2 switch with a DHCP server attached.

On 06/25/2015 10:29 AM, Char Jackson wrote:

[snip]

Within the context of a LAN, routers don't route. They are only (mostly) a
layer 2 switch with a DHCP server attached.


True. You're just using the switch, and maybe the WiFi access point. You
use the router itself only when accessing devices OUTSIDE your network.
That's usually internet.

With some routers (at least with DD-WRT) is can be a local DNS server
too. For example, I can access another computer by the name of:

gary.lan

instead of:

192.168.1.19

It also allows DNS redirection. Like a hosts file, but network-wide and
even works with devices that don't have a hosts file.

BTW, This is an important feature to me, so when I bought a new router a
couple of days ago, I made sure it was supported by DD-WRT.

--
Mark Lloyd
http://notstupid.us/

"Well, why did the Puritans come to this country?" a teacher asked his
history class. "To worship in their own way and to make other people do
the same" was the reply." [Frank Zindler]

In article ,
, Dave Doe says...

In article ,
, Bobbyville says...

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Check they're all in the same workgroup (suggested name: WORKGROUP)

Otherwise, I fear it's the famous Master Browser Election issue (which I
don't think it is, because you can't ping the PC's).

Also check in Control Panel, Network & Sharing Center, Advanced Sharing
settings - that Network Discovery and File and printer sharing is turned
on on all the PC's.

And on other thing, open a command prompt on each PC and look at the
results - post here if you wish...
ipconfig /all

If you note old IP's (from the old router, that may have had silly
(long) lease expirations), then do...
ipconfig /flushdns

--
Duncan.

On 6/25/2015 1:45 AM, Steve Hayes wrote:
On Thu, 25 Jun 2015 00:43:31 -0400, Bobbyville
wrote:

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Address clash?


They appear to have different addresses. Media-center 192.168.1.117 and
Desktop 192.168.1.104

On 6/25/2015 8:27 AM, Dave Doe wrote:
In article ,
, Bobbyville says...

I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Check they're all in the same workgroup (suggested name: WORKGROUP)

Otherwise, I fear it's the famous Master Browser Election issue (which I
don't think it is, because you can't ping the PC's).

Also check in Control Panel, Network & Sharing Center, Advanced Sharing
settings - that Network Discovery and File and printer sharing is turned
on on all the PC's.

Both computers claim they are in "WORKGROUP"
File and printer sharing is turned on for all PC's

Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt firmware on it.
Everything is working fine except two of the computers on the network can't communicate
with each other but they can both communicate with other computers on the network. For
example, I have 3 computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7. Before I got the new
router, all these computes could share files and remote desktop just fine with each
other. Now Desktop and media-center can't communicate at all with each other (they can't
ping each other, remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

Firewalls? (hardware, software)

On 6/25/2015 12:43 AM, Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

I've been experimenting and I've got some new information. I realized
that both the computers that couldn't communicate with each other are
both wired into the router. The Laptop (Lappy) was wireless and it can
communicate fine with both computers. So I decided to turn off the
wireless on Lappy and plug it into the router too. It then lost the
ability to communicate with Desktop and media-center. I unplugged Lappy
from the router and turned on the wifi again. Lappy could instantly
communicate with Desktop and media-center again.

So it appears to be an issue with the router. As mentioned above it is
TP-Link TL-WR841ND v9 running Firmwa DD-WRT v24-sp2 (12/22/14) std

On 6/26/2015 1:59 AM, Bobbyville wrote:
On 6/25/2015 12:43 AM, Bobbyville wrote:
I recently got a new router (TP-Link TL-WR841ND v9) and installed dd-wrt
firmware on it. Everything is working fine except two of the computers
on the network can't communicate with each other but they can both
communicate with other computers on the network. For example, I have 3
computers named Desktop, Lappy, and media-center. Media-center and
Lappy are both running Windows 8.1, and Desktop is running Windows 7.
Before I got the new router, all these computes could share files and
remote desktop just fine with each other. Now Desktop and media-center
can't communicate at all with each other (they can't ping each other,
remote desktop, or share files) but Lappy can communicate with both of
these computers just fine. Any ideas?

I've been experimenting and I've got some new information. I realized
that both the computers that couldn't communicate with each other are
both wired into the router. The Laptop (Lappy) was wireless and it can
communicate fine with both computers. So I decided to turn off the
wireless on Lappy and plug it into the router too. It then lost the
ability to communicate with Desktop and media-center. I unplugged Lappy
from the router and turned on the wifi again. Lappy could instantly
communicate with Desktop and media-center again.

So it appears to be an issue with the router. As mentioned above it is
TP-Link TL-WR841ND v9 running Firmwa DD-WRT v24-sp2 (12/22/14) std

Okay, after some Googling, I fixed it! It appears to be some sort of
bug with DD-WRT on some routers. Under the DD-WRT web interface, I went
to the Administration tab, and then the Commands Tab. There I entered:
swconfig dev eth0 set enable_vlan 1
swconfig dev eth0 set apply
That fixed it! The only thing is I'm going to have to add that to some
sort of startup script or I'll have to enter it everytime the router
reboots (which isn't often anyway). Note: according to the forums, some
people had to replace eth0 with eth1. Anyway, thanks for taking the
time and giving me all the advice!

On Fri, 26 Jun 2015 08:51:50 -0400, Wolf K wrote:

On 2015-06-26 2:28 AM, Bobbyville wrote:

Okay, after some Googling, I fixed it! It appears to be some sort of
bug with DD-WRT on some routers. Under the DD-WRT web interface, I went
to the Administration tab, and then the Commands Tab. There I entered:
swconfig dev eth0 set enable_vlan 1
swconfig dev eth0 set apply
That fixed it! The only thing is I'm going to have to add that to some
sort of startup script or I'll have to enter it everytime the router
reboots (which isn't often anyway). Note: according to the forums, some
people had to replace eth0 with eth1. Anyway, thanks for taking the
time and giving me all the advice!

Thanks for posting the solution. FFFR.

I'll try to save others from Googling.

FFFR probably means For Fast Future Reference

or some variation of that.

On Fri, 26 Jun 2015 11:45:47 -0400, Wolf K
wrote:

On 2015-06-26 10:29 AM, Char Jackson wrote:
On Fri, 26 Jun 2015 08:51:50 -0400, Wolf K wrote:

On 2015-06-26 2:28 AM, Bobbyville wrote:

Thanks for posting the solution. FFFR.

I'll try to save others from Googling.

FFFR probably means For Fast Future Reference

or some variation of that.

Typo, sorry. It shouda bin SFFR, Saved For Future Reference.


No, it shouda bin "Saved For Future Reference." Abbreviations should
always be avoided unless they are so commonly used that almost
everyone understands them.