Deja Vu all over again

John F. Kohler jkohler2 at earthlink.net
Fri Mar 30 21:36:46 PST 2001



ME wrote:

> Excelent. (Thanks for all of the data.)
>
> Here are some more things to try to help narrow the problem and perform
> diagnosis:
>
> What kernel version are you running? ( am assuming yuo are running a 2.2.x
> version kernel, but to find out try:
> # uname -a
>
> (Do you have firewall rules set at all with a v2.2.x kernel?)
> # ipchains -L -n
>
> (Let's try checking ICMP to some interfaces:)

OK, here I go:

>
> Warning: no SO_TIMESTAMP support, falling back to SIOCGSTAMP

PING 127.0.0.1 (127.0.0.1) from 127.0.0.1: 56(84) bytes of data
64 bytes from 127.0.0.1: icmp_seq=0 ttl=255 time=143 usec
--127.0.0.1 ping statistics--
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/mdev = 0.143/0.143/0.143/0.000 ms
[root at localhost john]#



>

>
> # ping -c 1 192.168.1.4

Warning: no SO_TIMESTAMP support, falling back to SIOCGSTAMP
PING 192.168.1.4 (192.168.1.4) from 192.168.1.4 : 56(84) bytes of data.

--- 192.168.1.4 ping statistics---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/mdev = 0.158/0.158/0.158/0.000 ms
[root at localhost john]#

>
> # ping -c 1 192.168.1.1

Warning: no SO_TIMESTAMP support, falling back to SIOGSTAMP
PING 192.168.1.1 (192.168.1.1) from 192.168.1.4: 56(84) bytes of data.

---192.168.1.1 ping statistics
1 packets transmitted, 0 packets received, 100% packet loss


(the last attempt to ping was from the linux box to the linkSys router.  It failed this
time
but has succeeded in the past . I cannot explain why.)



>
>
> (Output from each? Each will try to send only "1" ping out to the
> specified IP addresses.))
>
> I will assume this is a default install with no services turned off. If
> htis is the case, you should have "telnet" running on your local
> machine. Later you may want to look into turning this off depending upon
> how paranoid you are since you are behind a NAT translated router. For
> now, we can use it for testing.

Yes, in fact, I did complete a full installation and don't know how to turn
any of the services off.  It is probably true that "telnet" is installed and working
here.

>
>
> (Let's verify that you have it running:)
> # netstat -an | grep "LISTEN" | grep ":23"

Upon entering the command as shown above, I got no
acknowledgement it was done; just another root prompt.

>

>

>
>
> I'd like to have a TCP based service to test TCP as well as the ICMP above
> due to a problem with a network card/driver that I saw at an
> installfest. For this, we just need to connect to a service that uses
> TCP. Telnet, FTP, and the web parts (25, 21, and 80) generally offer TCP
> based service connections.
>
> If the above "netstat" reports something like:
> tcp        0      0 0.0.0.0:23              0.0.0.0:*               LISTEN
>

No response report similar to that above.  Just a root prompt

>
> or:
> tcp        0      0 127.0.0.1:23            0.0.0.0:*               LISTEN
> tcp        0      0 192.168.1.4:23          0.0.0.0:*               LISTEN
>
> we should be ok to test the following:
> # telnet 127.0.0.1 23

No login prompt; respons was
Trying 127.0.0.1//////
telnet: Unable to connect to remot host:  Connection refused
:23: bad port number

ame with port "25 and got a positive response:
Trying 127.0.0.1....
Connected to 127.0.0.1
Escape character is '^]'.
220 localhost.localdomain ESMTP Sendmail 8.11.0/8.11.0;Fri,30 Mar 2001 20:57:24 -0800

telnet>


>
> (If you see a login prompt appear, that is good. Just press conrol-d or
> press return a few tiumes until your connection is denied enough to have
> you disconnected and return you to your "#" prompt. If it "hangs" here ,
> then try control-c and note the problem in not being able to connect.)
>
> If the above works, then try:
> # telnet 192.168.1.4 23

It does not seem to work with "23" for telnet, strangely, it does seem to work
with "25" SMTP.  I don't understand that; further, after a (ctrl C)
I got the following prompt
telnet>

????

I stopped here for the night.  Will return tomorrow for more attempts
at this new procedure (for me!!) when I can report results more accurately.

John


>
> (Follow same above procedure if you get a login prompt like above. If you
> do not get a login prompt this is worthy to note.)
>
> If the above also works, we can try telnetting to the "web" port on the
> linksys router. (You stated it runs a web service.)
>
> For this we will have a different disconnect procedure than the above.
> # telnet 192.168.1.1 80
>
> You should see something like this, and your cuursor will probably just
> sit therer blinking at you without returning you a "#" prompt:
> Trying 192.168.1.1...
> Connected to 127.0.0.1.
> Escape character is '^]'.
>
> (If it just hangs at the part "Trying 192..." then you should be able to
> type control-c to get out. If you see the above, then you should be able
> to press control-] and then see a "telnet->" prompt to which you can type
> "quit" and then press return.
>
> Assuming that the ICMP "ping" test worked and the TCP based connections
> above worked, we can move on to test UDP and then try some DNS lookups.
>
> If all of the above provides us with the desired results, then we can look
> at UDP and/or DNS lookups with your DNS values.
>
> Your listed entries for resolv.conf may have typos in transcription or
> need some attention. try editing the file "etc/resolv.conf" and change it
> from:
>
> search earthlink.net
> nameserver 207.217.126.01
> nameserver 207.217.77.82
> nameserver207.217.120.83
>
> to
> search earthlink.net
> nameserver 207.217.126.81
> nameserver 207.217.77.82
> nameserver 207.217.120.83
>
> If the second paragraph is actually what you presently have then we should
> be able to go on.
>
> DNS allows for TCP and UDP based name lookup. Most of the time, name
> lookups occur over UDP. We can try using "nslookup" to see if your linux
> box can talk to the dns you specified int he above resolv.conf
>
> (My comments should not by typed in. They are specified within ( ) and
> left question marks "?" for values that may be different when you run your
> check:
>
> Here is a sample session in nslookup that I would like you to try:
> # nslookup
> Default Server:  ns1?.earthlink.net
> Address:  207.217.126.81? (or 207.217.77.82 or 207.217.120.83)
>
> > www.earthlink.net (type this in)
> Server:  ns1?.earthlink.net
> Address:  207.217.126.81? (or 207.217.77.82 or 207.217.120.83)
>
> Name:    www.earthlink.net
> Addresses:  207.217.114.220, 207.217.114.200
>
> > exit
> #
>
> At least one of the above tests should fail or unexpected information will
> be provided if you are still experiencing the problems with networking.
>
> Luckily, output from the above *should* be much shorter than everything
> else you have typed.
>
> if "ipchains" near the top pushes out a *lot* of stuff, then I'd try the
> file copy system mentioned before and do:
>
> # ipchains -L -n > /tmp/chainoutp.txt
> and then copy the "/tmp/chainoutp.txt" to floppy for attachment inclusion.
>
> Most of your values seem right (except for a leading zero for an octet on
> the resolv.conf and a missing space...)
>
> Now we are trying to test some of the parts and use some tools to see what
> happens.
>
> One thing that makes me think you had most of your settings properly set
> up, was an earlier statement where you said a traceroute worked, but a DNS
> lookup withing netscape failed.
>
> Thanks,
> -ME
>
> On Thu, 29 Mar 2001, John F. Kohler wrote:
>
> > Date: Thu, 29 Mar 2001 22:19:01 -0800
> > From: John F. Kohler <jkohler2 at earthlink.net>
> > Reply-To: nblug-talk at lists.sonic.net
> > To: nblug-talk at lists.sonic.net
> > Subject: Re: Deja Vu all over again
> >
> >
> >
> > ME wrote:
> >
> > > I am going to assume that this has not yet been resolved and take a stab
> > > at it. If this was resolved, and I did not notice, then skip this and
> > > please accept my appologies.
> > >
> > > Could you reboot your Linux box and then as root could you go to a command
> > > prompt and run the following command, and then take the contents of the
> > > output for each and paste them into one e-mail message for review on the
> > > list:
> > >
> > > # ifconfig
> >
> > eth0  Link encap: Ethernet HW addr 00:00:1C:56:C6:D1
> >         inet addr: 192.168.1.4  Bcast: 192.168.1.255 Mask: 255.255.255.0
> >          UP GROADCAST RUNNING MULTICAST MTU: 1500 Metric: 1
> >         Rx packets: 0 errors:0 dropped:0 overruns:0 frame :0
> >        Tx packets: 0 errors: 0 dropped:0 overruns:0 carrier:0
> >         collisions:0 txqueuelen:100
> >         Interrupt:10 Base Address:0x2a0
> >
> > lo     Link encap:Local Loopback
> >         inet addr: 127.0.0.1  Mask:255.0.0.0
> >         UP LOOPBACK RUNNING MTU: 3924  Metric:1
> >         RX packets :14 errors:0 dropped:0 overruns: 0 frame:0
> >         TX packets: 14 errors:0 dropped:0 overrruns:0 carrier: 0
> >         Colissions: 0 txqueuelen: 0
> >
> >
> > >
> > > # ifconfig eth0 same as above
> >
> > >
> > > # route -n
> >
> > Kernel IP routing table
> > Destination        Gateway        Genmask        Flags  Metric  Ref  Use Iface
> > 192.168.1.0      0.0.0.0        255.255.255.0  U        0        0       0   eth0
> > 127.0.0.0          0.0.0.0        255.0.0.0          U        0        0        0
> > lo
> > 0.0.0.0            192.168.1.1  0.0.0.0              UG     0        0        0
> > eth0
> >
> > >
> > > # cat /proc/interrupts
> >
> >                CPU0
> > 0:               304648            XT-PIC       timer
> > 1:                      113           XT-PIC       keyboard
> > 2:                        0             XT-PIC       cascade
> > 4:                        6             XT-PIC       serial
> > 8:                        1             XT-PIC       rtc
> > 9:                        0             XT-PIC       usb-uhci
> > 10:                      1             XT-PIC       NE2000
> > 13:                      1             XT-PIC       FPU
> > 14:               76601            XT-PIC       ide0
> > NMI:               0
> >
> >
> >
> > >
> > > # cat /proc/ioports
> >
> > 0000-001f : dma1
> > 0020-003f: pic1
> > 0040-005f: timer
> > 0060-006f: keyboard
> > 0070-007f: rtc
> > 0080-008f:dma page reg
> > 00a0-oobf:pic2
> > 00c0-00df: dma2
> > 00f0-00ff: fpu
> > 01f0-01f7:ide0
> > 02a0-02bf: ne2000
> > 02f8-02ff:serial (auto)
> > 03c0-03df:vga+
> > 03f6-03f6: ide0
> > o3f8-03ff: serial(auto)
> > e000-e00f: ide1
> > e400-e413: usb-uhci
> >
> > >
> > > # cat /resolve.conf
> >
> > search earthlink.net
> > nameserver 207.217.126.01
> > nameserver 207.217.77.82
> > nameserver207.217.120.83
> >
> >
> > >
> > > # dselect
> >
> > No such file or directory
> >
> > >
> >
> > >
> > > # lsmod
> >
> > Module                             Size    Used by
> > lockd                                31176   1 (autoclean)
> > sunrpc                            52964     1(autoclean)[lockd]
> > ppp                                20236      0 (autoclean) (unused)
> > slhc                                4504       0(autoclean) [ppp]
> > ne                                    6732      1(autoclean)
> > 8390                                6072     0(autoclean)[ne]
> > appgart                          18600     0(unused)
> > usb-uhci                        19052    0(unused)
> > usbcore                         42088    1[usb-uhci]
> >
> >
> >
> > >
> > >
> > > It is ok to just copy and paste them "as-is" and not try to format them on
> > > your own.
> > >
> >
> > Ihand transcribed them from the linux monitor to the mac.  Sorry about bad
> > format.
> >
> > >
> > > *OR*
> > >
> > > If you can be sure there is no file in "/tmp" called "netstuff.txt" then
> > > you could append a ">> /tmp/netstuff.txt" to the end of each of the
> > > commands listed above and then "attach" the file "/tmp/netstuff.txt" to
> > > your e-mail message you send to the list.
> > >
> > > Also, could you take one of your working machines (macs I think you said
> > > you had) on your network that shares use of the router and go to the
> > > TCP/IP control panel and give me the following information that should be
> > > listed in that control panel of that mac:
> >
> > the Mac LC 475 has the following in the "TCP/IP" control panel:
> >
> > >
> > > IP Address      :192.168.1.2
> > > Subnet Mask     :  255.255.255.0
> >
> > > Gateway/router  :192.168.1.1
> > > Domain Name Svrs: 207.217.126.81
> > >                                  207.217.77.82
> >
> >                                      207.217.120.83
> >
> > >
> > > Please also verify the network you have looks kind of like this:
> > > <!-- sorry about this html junk, I assume that the reason for the bad
> > > formatting of the previous messages was the use of a mail client by a
> > > sender that uses variable width fonts instead of fixed width fonts -->
> > >
> > > <pre>
> > > Mac1------|H|
> > > Mac2------|U|-- LINKSYS Router(?) --- DSL
> > > Linux Box-|B|
> > > </pre>
> > >
> >
> > The above is correct except for the hub, there is none.  The cat-5 cables all go
> > directly
> > to the router.  There is one cable from the router to the DSL modem ( or adapter)
> >
> >
> > >
> > > Does your Linksys router (? Assuming it is a router) only use DHCP to hand
> > > out IP addresses to clients? Does it allow you to set static addresses
> > > too?
> >
> > There are 3 choices for the router configuration; manual, DHCP, and BOOTP.
> > I have always used "manual" in the past.
> >
> > > Are the static addresses in the same range as the DHCP assigned
> > > addresses or does their manual only allow static addresses to be outside a
> > > certain range?
> >
> > Not using DHCP, so I assign the addresses
> > 192.168.1.2   (mac #1)
> > 192.168.1.3 ( mac#2)
> > 192.168.1.4 ( linux box)
> >
> > > Does the router implement rules to disallow any passing of
> > > packets from IP addresses that it does not have listed as having a DHCP
> > > lease? Do both of your macs get their address via DHCP/BootP or are they
> > > static assignments?
> >
> > If static assignments are the same as manual, yes.
> >
> > >
> > >
> > > Sorry to ask for all of this information again, but I would like to see it
> > > all after a reboot so we can be sure no other changes or oddness is in
> > > effect for this session.
> > >
> > > Thanks,
> > > -ME
> > >
> > > On Wed, 28 Mar 2001, John F. Kohler wrote:
> > > > I started the netscape browser (version 4.75) and tried to pull up the address
> > > > of
> > > > the router (192.168.1.1) .  On either macintosh also on the router, I get a
> > > > screen
> > > > with router setup information, and another screen indicating the router
> > > > is connected to the    DSL line.
> > > >
> > > > On the Linux box I got the following:
> > > >
> > > > Netscape:Error
> > > >
> > > > A network Error occurred.
> > > > Unable to connect to server (TCP error. No route to host)
> > > > The server may be down or unreachable.
> > > >
> > > > Try connecting again later.
> > > >
> > > > -30-
> > > >
> > > > Trying to ping the router ( 192.168.1.1) from the linux box (192.168.1.4)
> > > >
> > > >
> > > > I got the following sentence over and over again
> > > >
> > > > >From 192.168.1.4: Destination host Unreachable.
> > > >
> > > > Trying to get the box to ping its own IP address was successful
> > > > time was from 50 usec to 350 usec.
> > > >
> > > > Trying to get the linux box to ping the macintosh (lc475) next to it, was
> > > > successful
> > > >
> > > > getting times from 1.6 to 4.7 miliseconds.
> > > >
> > > > Didn't try to ping the iMac, it was turned off.
> > > >
> > > > John
> > > >
> > > >
> > > >
> > > > Dustin Mollo wrote:
> > > >
> > > > > It seems this message got stuck in the mailing list queue, so I'm resending
> > > > > it.  Enjoy!
> > > > >
> > > > > -Dustin
> > > > >
> > > > > ------------------------------------------------------------
> > > > >
> > > > > Date: Tue, 27 Mar 2001 11:20:16 -0800
> > > > > From: Mitch Petenaude <mrp at bolt.sonic.net>
> > > > > To: nblug-talk at lists.sonic.net
> > > > > Subject: Re: Deja Vu all over again
> > > > >
> > > > > Hi John,
> > > > >
> > > > > Have you set up your DNS server addresses? What is in /etc/resolv.conf?
> > > > >
> > > > >    --Mitch
> > > > >
> > > > > On Tue, Mar 27, 2001 at 09:16:29AM -0800, John F. Kohler wrote:
> > > > > > Although I could ping addresses outside my network, neither
> > > > > > Netscape nor Lynx could display a page.  So I am still
> > > > > > confused.
> > > > > >
> > > > > > I took a look at /etc/modules.conf
> > > > > >
> > > > > > alias parport_lowlever parport_pc
> > > > > > alias usb-controller usb-uhci
> > > > > > alias eth0 ne
> > > > > > options ne io=0x2a0 irq=10
> > > > > > ~
> > > > > > ~
> > > > > > ~
> > > > > > ~"modules.conf"4L, 109C"
> > > > > >
> > > > > > Here is /sbin/lsmod:
> > > > > >
> > > > > > Module                    Size    Used by
> > > > > > ide-cd                       23628`    0 (autoclean)
> > > > > > lockd                        31176      1 (autoclean)
> > > > > > sunrpc                       52964     1 (autoclean) [lockd]
> > > > > >
> > > > > > ppp                            20236     0
> > > > > > (autoclean)[unused]
> > > > > > slhc                             4504    0(autoclean) [ppp]
> > > > > > ne                                 6732   1  (autoclean)
> > > > > > 8390                              6072    0 (autoclean )
> > > > > > [ne]
> > > > > > agpgart                         18600 0 (unused)
> > > > > > usb-uhci                    19052 0 (unused
> > > > > > usbcore                      42088  1(usb-uhci)
> > > > > >
> > > > > > I  tried /proc/interrupts: and got permission denied.
> > > > > >
> > > > > > John
> > > > > >
> > > > >
> > > > > ----- End forwarded message -----
> > > >
> > > >
> >
> >




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