Internet connection trough ethernet switch

Hawdon · 2014-05-12 08:43:45

Hi!

I have a setup where I have multiple machines, all connected to the interent trough an old D-Link DES-1005D 10/100 Fast Ethernet Switch.
This works perfectly well with my Windows and Mac machines.

Now that I've installed Arch on my Asus S400C laptop, it won't connect when using the switch. If I remove the switch and connect it directly to the wall it works using
"systemctl start dhcpcd@ .service". If I do the same thing when connected to the switch, it will fail.

Here is a screenshot of the output of "ip link" and the dhcpcd:
http://i.imgur.com/VPDHdM9.png

Here is the output of the dhcpcd status after trying to connect trough the switch:
http://i.imgur.com/ZsGxIfq.png

I can see that the main error is "no IPv6 routers available", but what causes this and how can I fix it?

I also tried using avahi-autoipd to connect (included also "ip route show all" output):
http://i.imgur.com/TbSHddj.png

I have tried rebooting the switch, without any effect.

Any ideas?

Last edited by Hawdon (2014-05-12 11:08:12)

Rexilion · 2014-05-12 08:50:41

Maybe try assigning a static ip to confirm it's a dhcp issue?

Just pick a random ip from the pool and set the default route to the default route you usually get from the dhcp server. Make sure the random ip is not used by another computer.

Hawdon · 2014-05-12 10:44:12

I am still very confused about networking in general, but I gave setting a static ip a try.

I checked the default gateway when it was successfully connecting (without the switch) and it was 84.253.192.1.
I also checked the ip addresses of my Windows computer and my laptop which both are using the pattern 84.253.*.* so I used that for the ip.
They were also using the subnet mask of 255.255.224.0. And my laptop was using the broadcast address 84.253.223.225

So I set the ip using:

ip addr add 84.253.214.163/19 broadcast 84.253.223.225
ip route add default via 84.253.192.1

Tried pinging 8.8.8.8:

PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 84.253.210.83 icmp_seq=1 Destination Host Unreachable
From 84.253.210.83 icmp_seq=2 Destination Host Unreachable
From 84.253.210.83 icmp_seq=3 Destination Host Unreachable

--- 8.8.8.8 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 1999ms

So no luck.

Last edited by Hawdon (2014-05-12 10:44:32)

Rexilion · 2014-05-12 11:02:33

Hawdon wrote:

I am still very confused about networking in general, but I gave setting a static ip a try.

It's easier than you think.

Hawdon wrote:

I checked the default gateway when it was successfully connecting (without the switch) and it was 84.253.192.1.

That is probably the WAN (internet) ip. Usually, most consumers have a seperate pool for home use. These ip's are LAN only and are not valid on the internet.

You could look here. So, examples are 10.0.0.0 - 10.255.255.255, 172.16.0.0 - 172.31.255.255 and 192.168.0.0 - 192.168.255.255.

Hawdon wrote:

I also checked the ip addresses of my Windows computer and my laptop which both are using the pattern 84.253.*.* so I used that for the ip.
They were also using the subnet mask of 255.255.224.0. And my laptop was using the broadcast address 84.253.223.225

That's odd. That would imply you receive an ip directly from your ISP for each client in your local network. So, what I said above is probably not true (I kept it there for clarity).

Hawdon wrote:

So I set the ip using:

ip addr add 84.253.214.163/19 broadcast 84.253.223.225
ip route add default via 84.253.192.1

That looks sane, given your above observations.

Hawdon wrote:

Tried pinging 8.8.8.8:

PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
From 84.253.210.83 icmp_seq=1 Destination Host Unreachable
From 84.253.210.83 icmp_seq=2 Destination Host Unreachable
From 84.253.210.83 icmp_seq=3 Destination Host Unreachable

--- 8.8.8.8 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 1999ms

So no luck.

I suggest the following: You seem to have taken 'an' ip from the router. Routers usually have 2 of these (on for the local network and one for the internet). However, you seem to indicate that this is not the case.

I suggest you do the following:

- plugin the lan switch
- connect a computer that works
- from this computer obtain: the default route, the default dns and it's ip.

On Arch, do something like this:

ip addr add (ip from other comp + 1)/19 dev enp3s0
ip route add default via (default router ip taken from other comp)
echo "nameserver (dns ip from other comp)" > /etc/resolv.conf

Make sure that the properly working Mac or Windows computer is connected to the same switch as the laptop.

Last edited by Rexilion (2014-05-12 11:03:25)

Kartious · 2014-05-12 11:04:17

I would go for the range that your router or the DHCP service is allocating rather than using other machines as a reference, I am guessing your network sub-netted?

Also I would change the images into links as they stand a risk of getting removed, they should be no bigger than 250x250 + 50kb in size. All of your images exceeds both the criteria.

Uploading Pictures

Edit :: Rex is always just too good at elaborating solutions, usually nothing more can be said!

Last edited by Kartious (2014-05-12 11:06:24)

Hawdon · 2014-05-12 11:09:24

Some more info about my network:
I live in an student apartment building, I have 1 ethernet plug in my apartment (1 room) that I can use and I have no access to the router.

And thanks for the tip Kartious, I changed the images to links.

Kartious · 2014-05-12 11:14:59

Hawdon wrote:

Some more info about my network:
I live in an student apartment building, I have 1 ethernet plug in my apartment (1 room) that I can use and I have no access to the router.
And thanks for the tip Kartious, I changed the images to links.

Thanks for making the changes so quickly, it is appreciated. Can I also just ask if there is a proxy involved ? Sometimes Windows and Macs can automatically pick up the proxy settings where as on a Arch system you would need to manually configure it.

Hawdon · 2014-05-12 11:27:17

I far as I know there is no proxy. Is there a way to check to make sure?

Rexilion · 2014-05-12 11:33:06

Hawdon wrote:

I far as I know there is no proxy. Is there a way to check to make sure?

For starters. The ip assigned to your local box should be the same as the ip displayed here.

Hawdon · 2014-05-12 11:37:23

It's the same.

Arch Linux

#1 2014-05-12 08:43:45

Internet connection trough ethernet switch

#2 2014-05-12 08:50:41

Re: Internet connection trough ethernet switch

#3 2014-05-12 10:44:12

Re: Internet connection trough ethernet switch

#4 2014-05-12 11:02:33

Re: Internet connection trough ethernet switch

#5 2014-05-12 11:04:17

Re: Internet connection trough ethernet switch

#6 2014-05-12 11:09:24

Re: Internet connection trough ethernet switch

#7 2014-05-12 11:14:59

Re: Internet connection trough ethernet switch

#8 2014-05-12 11:27:17

Re: Internet connection trough ethernet switch

#9 2014-05-12 11:33:06

Re: Internet connection trough ethernet switch

#10 2014-05-12 11:37:23

Re: Internet connection trough ethernet switch

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