[SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

DeltaII · 2015-07-06 16:07:00

Full disclosure: This is on my apartment's network, which is essentially a school network run by a company called "Airwave." I am at my wit's end with them...

This is all on a wired network, with my desktop - which doesn't even have a wireless card - so wi-fi isn't an option.

A couple days ago, my internet connection just stopped working. It was working fine when I left my machine, I let it idle for 3-4 hours while I was out, and I came back to find my internet dead.
Reboot didn't help.

The only special config I have is a timeout delay because the building's network takes forever to respond.

I've already tried everything in both the Network Configuration and dhcpcd wiki articles.

The weird thing is that I do get an IP:

$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether fc:aa:14:94:28:da brd ff:ff:ff:ff:ff:ff
    inet 172.16.72.112/24 brd 172.16.72.255 scope global eno1
       valid_lft forever preferred_lft forever
    inet6 fe80::f664:f0:f2a4:102b/64 scope link 
       valid_lft forever preferred_lft forever

where eno1 is my wired interface,

but I can't access outside websites:

$ ping -c 3 www.google.com
PING www.google.com (74.125.228.241) 56(84) bytes of data.

--- www.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2008ms

Outputs of ip link and ip route:

$ ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether fc:aa:14:94:28:da brd ff:ff:ff:ff:ff:ff

$ ip route
default via 172.16.72.1 dev eno1  metric 202 
172.16.72.0/24 dev eno1  proto kernel  scope link  src 172.16.72.112  metric 202

Thanks in advance for any advice. I'm admittedly terrible at network anything.

Last edited by DeltaII (2015-07-06 23:25:50)

rsmarples · 2015-07-06 16:10:18

Can you ping the router?

ping 172.16.72.1

ms · 2015-07-06 16:12:42

Please provide /etc/resolv.conf and try ping with IP address (e.g. bbs.archlinux.org is 5.9.250.164).

Last edited by ms (2015-07-06 16:31:18)

R00KIE · 2015-07-06 16:27:29

You might also want to get hold of mtr/traceroute/tcptraceroute and see where things might be being dropped.

DeltaII · 2015-07-06 17:17:12

Ok, here we go:

Ping the router: good.

$ ping 172.16.72.1
PING 172.16.72.1 (172.16.72.1) 56(84) bytes of data.
64 bytes from 172.16.72.1: icmp_seq=1 ttl=64 time=0.658 ms
64 bytes from 172.16.72.1: icmp_seq=2 ttl=64 time=0.270 ms
64 bytes from 172.16.72.1: icmp_seq=3 ttl=64 time=0.276 ms
64 bytes from 172.16.72.1: icmp_seq=4 ttl=64 time=0.237 ms
64 bytes from 172.16.72.1: icmp_seq=5 ttl=64 time=0.270 ms
64 bytes from 172.16.72.1: icmp_seq=6 ttl=64 time=0.269 ms
64 bytes from 172.16.72.1: icmp_seq=7 ttl=64 time=0.269 ms
64 bytes from 172.16.72.1: icmp_seq=8 ttl=64 time=0.239 ms
64 bytes from 172.16.72.1: icmp_seq=9 ttl=64 time=0.271 ms

--- 172.16.72.1 ping statistics ---
9 packets transmitted, 9 received, 0% packet loss, time 7998ms
rtt min/avg/max/mdev = 0.237/0.306/0.658/0.126 ms

Ping Arch forums via IP: not so good.

$ ping 5.9.250.164
PING 5.9.250.164 (5.9.250.164) 56(84) bytes of data.

--- 5.9.250.164 ping statistics ---
10 packets transmitted, 0 received, 100% packet loss, time 9007ms

My /etc/resolv.conf:

# Generated by resolvconf
nameserver 8.8.8.8
nameserver 8.8.4.4

And a tracepath to 8.8.8.8 (traceroute not installed) :

 1?: [LOCALHOST]                                         pmtu 1500
 1:  gateway                                               0.787ms 
 1:  gateway                                               1.645ms 
 2:  no reply
 3:  no reply
 4:  no reply
 5:  no reply
 6:  no reply
 7:  no reply
 8:  no reply
 9:  no reply
10:  no reply
11:  no reply
12:  no reply
13:  no reply
14:  no reply
15:  no reply
16:  no reply
17:  no reply
18:  no reply
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20:  no reply
21:  no reply
22:  no reply
23:  no reply
24:  no reply
25:  no reply
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27:  no reply
28:  no reply
29:  no reply
30:  no reply
     Too many hops: pmtu 1500
     Resume: pmtu 1500

I'm at work now but can try to install traceroute offline (if it would help) when I get back.

WorMzy · 2015-07-06 17:25:32

Looks like the problem is at the router's end, not your PC's. Do you have access to the router? If not, you probably need to contact your apartment's network team (assuming this is a university halls style setup).

DeltaII · 2015-07-06 17:29:20

Nope, no access.

I had feared that was the case. (For the record, Windows still connects fine, but Linux? Who uses that, right?) It's more or less a university hall set up (off campus housing, but run university style).

Thanks anyway, everyone.

WorMzy · 2015-07-06 17:33:46

Wait, if Windows works, then I'm probably wrong. How is Windows connecting? Do you need to authenticate somehow?

DeltaII · 2015-07-06 17:37:09

Oops, I should have mentioned that before. Yeah.

So authentication is...weird. It's ostensibly supposed to pop up a browser on connection with the login screen, but that almost never happens for me (once every 6 months on average). On Windows, it usually redirects to MSN (the building's "approved homepage") and I'm fine. On Linux, both Arch and Mint, I've never had to do anything with regards to authentication until now.

ewaller · 2015-07-06 17:41:02

How about if you disable IPv6. https://wiki.archlinux.org/index.php?ti … sable_IPv6

DeltaII · 2015-07-06 17:43:32

I will try that as well.

ms · 2015-07-06 17:44:51

@Deltall, You should check if your network use automatic proxy. That my best guess. Boot to Windows and check in network connection if its setting up proxy automatically.

Another guess, your browser block login screen (probably pop-up block addons or ads block).

DeltaII · 2015-07-06 23:15:35

Ok:

Disabling IPv6 didn't help - same results. Though I do note that Windows has no IPv6 connectivity, so it's possible this was at least part of the issue.

Adblock has no effect - disabling it didn't help, and I run the same setup on Windows (and Linux Mint) -- Firefox with Ablock Plus -- with no issue.

As far as I can tell, I'm not behind a proxy, either. WIndows doesn't appear to be connecting to one.

EDIT: I lied! It took two reboots for some reason, but internet access is back. I strongly suspect disabling IPv6 is what fixed it.

Serious thanks to everyone who pitched in here!

Last edited by DeltaII (2015-07-06 23:23:03)

Trilby · 2015-07-06 23:19:46

Those redirect-login pages are always crap. While everyone who knows the "theory" behind them denies that it should happen, my experience has made if very clear that many of those will only redirect specific urls to the login page while everything else just hangs. google.com is the most frequently redirected - but at my local book store I have to point my browser to barnesandnoble.com to get redirected to the login page, nothing else will work.

So try a handful of common urls and some that might be related to the school/company/organization there.

Arch Linux

#1 2015-07-06 16:07:00

[SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#2 2015-07-06 16:10:18

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#3 2015-07-06 16:12:42

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#4 2015-07-06 16:27:29

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#5 2015-07-06 17:17:12

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#6 2015-07-06 17:25:32

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#7 2015-07-06 17:29:20

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#8 2015-07-06 17:33:46

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#9 2015-07-06 17:37:09

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#10 2015-07-06 17:41:02

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#11 2015-07-06 17:43:32

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#12 2015-07-06 17:44:51

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#13 2015-07-06 23:15:35

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

#14 2015-07-06 23:19:46

Re: [SOLVED]dhcpcd gets lease for an IP address, still can't ping anything

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