RE: [MLUG] RTNETLINK answers: Network is unreachable

["Cutts III, James H." <EMAIL:PROTECTED>]

The "tcpdump" command gets "stuff" coming by on the screen.  It looks
like a time stamp, protocols, addresses,...

I've run "iptraf" and I'm getting UDP packets on ports 138, 137, 123, 68
and 67.

Last night I moved the machine to a new port and since then, I've moved
it back to the same port.  I guess it may be a VLAN issue.  

I'll check with campus networking to see if this may resolve my issues.


Thanks for the suggestions and the explanations.

James H. Cutts III
CARES & CORI - 143C Mumford

 

> -----Original Message-----
> From: EMAIL:PROTECTED 
> [mailto:EMAIL:PROTECTED] On Behalf Of Bryan Venable
> Sent: Wednesday, April 11, 2007 12:03 PM
> To: MLUG Members
> Subject: Re: [MLUG] RTNETLINK answers: Network is unreachable
> 
> When you connect to your original network port (not the 
> netgear) and run (as root):
> 
> tcpdump -i eth0 -n
> 
> What kind of traffic do you see? If you aren't getting 
> anything, but your NIC has link, then your port may have been 
> blocked or removed from the VLAN.  It sounds like you don't 
> manage the switch you are connecting to.  Have you contacted 
> the network admin(s)?  If you changed which port you were 
> connecting to, they may purposefully have security mechanisms 
> in place to prevent that change from "just working".
> 
> If you *do* see traffic, and you changed ports, then the new 
> port may simply be on a different VLAN, in which case you 
> should see broadcast traffic that will indicate what VLAN it 
> is.  If that happens you will need the network admin(s) to 
> change the VLAN membership of that port or you will need to 
> change your server's IP, whichever is simplest - I'd guess 
> the VLAN change.
> 
> If you didn't change ports then there still could be 
> something going on at the switch.  In general, if you have 
> link and your interface and routing configurations are the 
> same, the problem will be at the switch.  Unless it's been an 
> exceptionally long time since the server was rebooted, the 
> chances that your configuration changed unexpectedly are slim to none.
> 
> Good luck.
> 
> 
> On 4/11/07, Cutts III, James H. <EMAIL:PROTECTED> wrote:
> >
> >
> > Jason,
> >
> > The commands you suggested did not generate any error messages, nor 
> > did they solve the problem.
> >
> > I tried the netmask and gateway you suggested - it didn't work.  :-(
> >
> > Then I tried the netmask and gateway in my ifcfg-eth0 - it 
> didn't work 
> > either.  :-(
> >
> > Michael Proctor asked about changing the changing NICs.  I 
> have heard 
> > of that happening.  I hadn't thought of that.  When I unplug the 
> > network cable, the box protests that "e100: eth0 Link is 
> Down".  This 
> > makes me believe that I've got the right card and cable.
> >
> > I have borrowed a "simple" 4 port Netgear (wireless) router.  If I 
> > plug the box in to the router and ping something I see the 
> lights on 
> > the router blink.  Any suggestions of ways to use this 
> router to see 
> > what is actually getting shoved out of the box?
> >
> >
> >
> >
> >
> >
> >
> > James H. Cutts III
> >
> > CARES & CORI - 143C Mumford
> >
> >
> >
> >  ________________________________
> >  From: EMAIL:PROTECTED 
> > [mailto:EMAIL:PROTECTED] On Behalf Of 
> McIntosh Jason
> > Sent: Wednesday, April 11, 2007 10:33 AM
> > To: Members MLUG
> >
> > Subject: Re: [MLUG] RTNETLINK answers: Network is unreachable
> >
> >
> > Hrmm, I re-read the original email.  If you try turning off the 
> > interface (i.e. ifdown eth0) then try:
> > ifconfig  eth0 128.206.25.130 netmask 255.255.255.0 up route add 
> > default gw 128.206.25.254
> >
> >
> > (I think that's the syntax off the top of my head) - see if 
> that gets 
> > you up and running.  if so, then it is an issue with your 
> network configuration.
> > i.e. the syntax for the files in /etc/sysconfig/network/ 
> have changed, 
> > or something along those lines.  ifup and ifdown merely are 
> shortcuts 
> > to execute the ifconfig command with the appropriate information 
> > pulled from those files.
> >
> >
> > Jason
> >
> >
> >
> > /--------------------------------------|---------------------------\
> > | Jason McIntosh                       | CELL: 573-424-7612        |
> > | Webmaster, thinker, programmer, etc. | WORK: 573-884-3865        |
> > | http://mcintosh.poetshome.com/blog/  |
> >        |
> > |------------------------------------------------------------------|
> > |"How should I know if it works?  That's what beta testers are     |
> > |for.  I only coded it."                                           |
> > |(Attributed to Linus Torvalds, somewhere in a posting)            |
> > \--------------------------------------|---------------------------/
> >
> >
> >
> >
> >
> > On Apr 11, 2007, at 10:24 AM, McIntosh Jason wrote:
> >
> > They have changed, but that won't prevent a network connection from 
> > happening.  That's just for DNS resolution (i.e. how to convert 
> > mlug.missouri.edu to 128.206.whatever).
> > This issue sounds more like binding the driver to the 
> interface.  It 
> > is worth trying another network card though to see if it 
> might work better.
> > Jason
> >
> >
> >
> > /--------------------------------------|---------------------------\
> > | Jason McIntosh                       | CELL: 573-424-7612        |
> > | Webmaster, thinker, programmer, etc. | WORK: 573-884-3865        |
> > | http://mcintosh.poetshome.com/blog/  |
> >        |
> > |------------------------------------------------------------------|
> > |"How should I know if it works?  That's what beta testers are     |
> > |for.  I only coded it."                                           |
> > |(Attributed to Linus Torvalds, somewhere in a posting)            |
> > \--------------------------------------|---------------------------/
> >
> >
> >
> >
> >
> > On Apr 11, 2007, at 10:22 AM, George Robb wrote:
> >
> >
> > Didn't the name servers change from 2.252 to  128.206.10.3 
> and 128.206.10.2?
> >
> >
> > You may want to call the op's center 4-2182 and double check me.
> >
> >
> > Worst case comment out the current nameserver entries and 
> manually add 
> > the new ones.
> >
> >
> > A shot in the dark...  ;)
> >
> >
> > George
> >
> >
> >
> >
> > On Apr 11, 2007, at 10:04 AM, Cutts III, James H. wrote:
> >
> >
> >
> > Ah, debugging questions.  I can deal with them.
> >
> >
> > Static IP: 128.206.25.130
> >
> >
> > /etc/resolv.conf
> > nameserver 128.206.2.252
> > nameserver 128.206.2.242
> > search missouri.edu
> >
> >
> > Yes, I've checked the cables.
> >
> >
> > The server is on a VLAN in the MU system.  Might there be a problem 
> > beyond my port?
> >
> >
> > Thanks,
> > James.
> >
> >
> >
> >
> > -----Original Message-----
> > From: EMAIL:PROTECTED 
> > [mailto:EMAIL:PROTECTED] On Behalf Of George Robb
> > Sent: Wednesday, April 11, 2007 9:51 AM
> > To: MLUG Members
> > Subject: Re: [MLUG] RTNETLINK answers: Network is unreachable
> >
> >
> > Are you static or dynamic for your IP?  What does your /etc/ 
> > resolv.conf look like?  Double checked that your cable is good?
> >
> >
> > ;)
> >
> >
> > George
> >
> >
> > On Apr 11, 2007, at 9:45 AM, Cutts III, James H. wrote:
> >
> >
> >
> > I needed to move my production server, Ronald, (running Red Hat 9
> > (Shrike) 2.3.20-31.9) while reconfiguring the server room.  
> The room 
> > is nicely rearranged and ready for the return of the computers.
> >
> >
> > After issuing the "halt" command Ronald, issued a few protest about 
> > it's inability to umount /usr2 due to a file being too large.  But 
> > otherwise it went down nicely (I think).
> >
> >
> > I've restarted the box and everything appears to be running nicely -
> > except that it can't get to nor be seen by the internet (nor campus
> > network for that matter).
> >
> >
> > A "/sbin/ifup eth0" produces the responses:
> > e100: eth0 NIC Link is Up 100 Mbps Half duplex
> > RTNETLINK answers: Network is unreachable
> > RTNETLINK answers: Invalid argument
> >
> >
> > I've been "visited" by my boss and received comments from users
> > that the
> > server is down.  Their comments haven't been helpful, hopefully MLUG
> > members will be more constructive.
> >
> >
> > Please!
> >
> >
> > James H. Cutts III
> > CARES & CORI
> > MU
> >
> >
> >
> >
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> >
> >
> >
> >
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> >
> >
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> >
> >
> >
> >
> > _______________________________________________
> > members mailing list
> > EMAIL:PROTECTED
> > http://mlug.missouri.edu/mailman/listinfo/members
> >
> > _______________________________________________
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> > EMAIL:PROTECTED
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> >
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> >
> >
> 
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