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[duke] n00b
Joined: 22 Sep 2004 Posts: 10 Location: Warstein, Germany
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Posted: Wed Sep 22, 2004 10:08 pm Post subject: Ultra5 & network problems |
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Hi all!
I recently wanted to install gentoo on my Ultra5. Booting etc. worked fine, but I wasn't able to get my net working.
NIC was detected correctly (SUN Happy Metal), it got the ip-address from dhcp, too. But now everything is going _very_ strange: I'm not able to ping anything. A tcpdump on my local server shows all icmp echo-requests from the Ultra to my workstation, the workstation replied as expected ... but the Ultra only shows "destination unreachable". I looked after the arp-tables on both machines and, surprise, both got the correct entries for each other!
Same procedure with my server ... with same result => "destination unreachable", arp-entires correct. Same result the other way round, too.
I tried again with manual ip-settings, but without success :/
Anyone with some hints for me?
Note: routing is correct, link is up, switch is working 100%, too!
Bye,
Michal |
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labrador Guru
Joined: 04 Oct 2003 Posts: 316
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Posted: Thu Sep 23, 2004 2:35 am Post subject: Network troubleshooting... |
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Try the tracing tips mentioned for a similar problem in this thread:
https://forums.gentoo.org/viewtopic.php?t=224857
Don't depend too much on ping. Firewalls often block it, and some networks
just don't allow the traffic (such as the University where I work). |
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[duke] n00b
Joined: 22 Sep 2004 Posts: 10 Location: Warstein, Germany
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Posted: Thu Sep 23, 2004 7:26 am Post subject: Re: Network troubleshooting... |
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Thx for your reply ...
I read the thread you pointed me to before, but it's not the situation I got here. I'm not able to ping anything, not even my gateway. My firewall is not blocking any internal traffic, too. But yes, I double-checked anything (IP, netmast, broadcast, gateway, correct routing-table, firewall etc.pp.).
And I tried ssh, too ... with the same result: no connection, only arp-requests.
Next thing I'll try tonight is setting arp-entries by hand ... but maybe someone has a better solution?
Bye,
Michael _________________ Although the Perl Slogan is There's More Than One Way to Do It, I hesitate to make 10 ways to do something. :-)
--Larry Wall in <9695@jpl-devvax.JPL.NASA.GOV> |
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labrador Guru
Joined: 04 Oct 2003 Posts: 316
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Posted: Fri Sep 24, 2004 2:29 pm Post subject: I still say don't over-rely on ping |
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Depending on who is administering your network, pings may be
useless. On my campus, CMP traffic is limited on the Cisco switch
level, so it has nothing to do with what firewalls are in use.
I can't ping between 2 machines that I control even when
there is no firewall operating.
Test with other methods that use TCP/IP, not only ping.
http://216.109.118.67/
should bring you to a yahoo page in a browser, even if DNS
isn't set up and CMP traffic is filtered out on the switch or gateway. |
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[duke] n00b
Joined: 22 Sep 2004 Posts: 10 Location: Warstein, Germany
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Posted: Fri Sep 24, 2004 9:07 pm Post subject: Re: I still say don't over-rely on ping |
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Well, it's my own network at home, so I know what's restricted/allowed in there ;)
Nevertheless, as I said before, I tried ssh with the same result => no connection.
I tried telnet with some external IP's, too (eg. my server at our company or 216.239.59.99:80).
Setting arp-entries by hand did not solve the problem, so I have to think about sth. other ...
Bye,
Michael _________________ Although the Perl Slogan is There's More Than One Way to Do It, I hesitate to make 10 ways to do something. :-)
--Larry Wall in <9695@jpl-devvax.JPL.NASA.GOV> |
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labrador Guru
Joined: 04 Oct 2003 Posts: 316
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Posted: Fri Sep 24, 2004 10:54 pm Post subject: other tests |
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Then I guess you need to check the essentials...
does 'ifconfig eth0' show anything for the stats and errors
on the device?
For example, I see this on one of my machines right now:
Code: | RX packets:176266 errors:0 dropped:0 overruns:0 frame:0
TX packets:116380 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:77365381 (73.7 Mb) TX bytes:14852918 (14.1 Mb) |
Can you ping 127.0.0.1 ?
Is it any different if you switch for a known good cable?
Depending on how well you know networking (it sounds like
you know it quite well) you might want to try using
route commands rather than manipulating arp tables directly.
Sometimes the lower level approach provides too much
room to make a mistake. |
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