Expanded my home network, but now suffering packet losses

Nate--IRL-- · 30 May 2009 at 17:30

EDIT:- Solution found, thanks for the help folks.

As per title, I expanded my home network by adding a cheap 8port switch, in order to move some some stuff off wireless as well as improving the reliability and connectivity of the network.

However after moving stuff around I have been suffering a 15-20% packet losses on one particular and important leg of the network. I'm not an expert on networks at all, and have no idea why this might be happening. I am probably overlooking something obvious.....

I should mention that most devices on the network have been given static IPs and there is DCHP (or DHCP I can never remember which it is) on the wireless router (see maps below) for any other devices that need IPs.

I have drawn 2 maps of the network as it was and as it is now. If anybody could suggest a reason for the packet loss I would be most grateful.

OLD network

NEW Network

Nate

Edit:- Maps corrected to show correct config

m_cozzy · 30 May 2009 at 17:32

adsl modem should be plugged into the router, then plug the new switcj into the router also, suprised it working at all tbh

Nate--IRL-- · 30 May 2009 at 17:42

Sorry I should have mentioned that the Modem is kinda a 1 port router too, it can perform DHCP (DCHP?) functions too, though that is disabled in favour of the main router. Netgear DG632

Nate

tolien · 30 May 2009 at 17:43

But you're using it as just a modem, then using the other one as a router?

Nate--IRL-- · 30 May 2009 at 17:53

Maybe I'm getting my terms mixed up here (Switch, modem, router etc.) I warned that I was no expert

The "Modem/router" is the gateway to the internet (it's IP is 192.168.0.1) that is its sole function, DCHP off etc.

The "switch" is dumb, sits there distributing packets to IPs.

The "Wireless Router" is just intended to be another switch that can perform DCHP functions if needed (its IP is 192.168.0.11).

Hopefully that makes it a bit clearer.
Nate

tolien · 30 May 2009 at 18:15

So the ADSL modem is actually a modem/router, and the "4 port router w/ wireless" is really just a switch and wireless access point?

Try another cable between the switch and the wireless box.

Nate--IRL-- · 30 May 2009 at 20:07

tolien said:
So the ADSL modem is actually a modem/router, and the "4 port router w/ wireless" is really just a switch and wireless access point?

Try another cable between the switch and the wireless box.

Strangely, by swapping the 4Port wireless/switch and 8port switch around, the problem seems to have vanished, very odd, this was bugging me for days. Annoying, but a result

Nate

Zarf · 30 May 2009 at 20:12

Is their packet loss between "J's computer" and "My computer" or the wired laptop?

Nate--IRL-- · 30 May 2009 at 20:46

Zarf said:
Is their packet loss between "J's computer" and "My computer" or the wired laptop?

No, they were fine, which is what I found puzzling. The only problem was the route between the two switches, which for whatever reason now works as it should after swapping them around. (!?) Still testing it at the moment, but it appears to be fixed.

Nate

russ0r · 1 Jun 2009 at 15:13

Dodgy cable probably.

Mav · 1 Jun 2009 at 19:26

does ya hubs have a uplink switch on any of them to daisy chain hubs ??

or a port marked up as uplink ??

or are they auto sensing ?

Nate--IRL-- · 1 Jun 2009 at 19:36

Mav said:
does ya hubs have a uplink switch on any of them to daisy chain hubs ??

or a port marked up as uplink ??

or are they auto sensing ?

I'm assuming they are auto sensing, as there is no up link port or switch I can see.

Anyhow by switching the switches around everything seems to be running fine. My suspicion is that the Cheap 8Port switch I bought isn't up to the task of being the main hub of the network, but now is performing flawlessly as the downstairs hub.

The only downside to this is now my laptop has to go back using the wireless connection, which is no great hardship.

Nate

Nate--IRL-- · 2 Jun 2009 at 17:20

Nate--IRL-- said:
I'm assuming they are auto sensing, as there is no up link port or switch I can see.

Nate

Well well, I've finally sussed it. The problem returned this morning, and I was ready to rip the whole thing apart. Then I started thinking about what Mav said about Uplink and autosensing connections. It appears that the Cheap 8port hub has no way of detecting if a port is being used as an uplink, however the 4port w/wireless does. However.....

If the 4port switch is turned on or rebooted before the 8 port switch is on, the network drops most, but not all, the packets between the two switches. If the 8port hub is turned on first, everything performs as it should, as the 4port switch detects the uplink connection.

I'm glad i finally understand the problem now.

Nate

tolien · 2 Jun 2009 at 18:24

So it was actually a hub, not a switch?

Skidilliplop · 2 Jun 2009 at 19:26

When interconnecting two like network devices, be it hub or switch or whatever I always use a crossover cable. Purely because most of the time the ports are auto sensing and it makes no odds but when they're not it avoids problems like this.
Most people think it's old fashoned to do it that way but as far as I'm concerned it's one less thing to go wrong. Which is always good thing.

Nate--IRL-- · 2 Jun 2009 at 22:00

tolien said:
So it was actually a hub, not a switch?

LOL, please forgive my ignorance, but what is the difference between the two?

The 8port "device" is labeled a switch on the front of it. and the 4Port w/wireless has Wireless router written on the front of it, although I am using it only as a switch ( ...or hub... oh god). This, along with my general networking ignorance has lead to the confusion, sorry folks.

Nate

tolien · 2 Jun 2009 at 22:37

Nate--IRL-- said:
LOL, please forgive my ignorance, but what is the difference between the two?

Wikipedia said:
In the context of a standard 10/100 Ethernet switch, a switch operates at the data-link layer of the OSI model to create a different collision domain per switch port. If you have 4 computers A/B/C/D on 4 switch ports, then A and B can transfer data between them as well as C and D at the same time, and they will never interfere with each others' conversations. In the case of a "hub" then they would all have to share the bandwidth, run in half-duplex and there would be collisions and retransmissions. Using a switch is called micro-segmentation. It allows you to have dedicated bandwidth on point to point connections with every computer and to therefore run in full duplex with no collisions.

Hubs broadcast traffic on every port, switches do not.

Mav · 2 Jun 2009 at 23:12

well nate i`am glad ya got it sussed m8 , @ least u know now

sometimes it`s that flash of a idea that takes u to the answer

MarkW7 · 2 Jun 2009 at 23:22

tolien said:
Hubs broadcast traffic on every port, switches do not.

Yep, hubs get the traffic and then send it to every single port on the hub were as switches only send it to the person that is asking for it making it faster