I would like to give some update and ask help again:
problem:  unable to access remote cvs server (my desktop) from fermi 
machines

[cmswn082] cvs login
Logging in to 
:pserver:[log in to unmask]:2401/var/lib/cvsroot
CVS password:
cvs [login aborted]: connect to 
neutralino.physics.uiowa.edu(128.255.34.167):2401 failed: No route to host

[cmswn082] telnet neutralino.physics.uiowa.edu 2401
Trying 128.255.34.167...
telnet: Unable to connect to remote host: No route to host


When I tried to see if port 2401 listens, I see that it does
[root@neutralino]# netstat -an | grep LISTEN | grep 2401
tcp        0      0 0.0.0.0:2401                
0.0.0.0:*                   LISTEN

[root@neutralino]# /sbin/chkconfig --list cvspserver
cvspserver      on


My /etc/xinetd.d/cvspserver looks like
service cvspserver
{
        port               = 2401
        socket_type        = stream
        protocol           = tcp
        wait               = no
        user               = root
        passenv            = PATH
        server             = /usr/bin/cvs
        server_args        = -f --allow-root=/var/lib/cvsroot pserver
        log_type           = FILE /var/log/cvspserver
        env                = HOME=/usr/cvs
        disable            = no
}

and hosts.allow and host.deny

hosts.allow:

cvs: LOCAL

hosts.deny: empty


How can I find out the reason for no connection?

Thanks,
Taylan



Maxim kovgan wrote:
> well, go and search for the firewalls on the way now.
> with a clear conscience.
> :)
>
>
>
> Taylan Yetkin wrote:
>> I couldn't find how to capture ipv6 packets but I disabled it to see 
>> if it makes any difference. Actually I still get the same
>>
>
>
> assuming your interface of question is eth0:
> tcpdump -vvv -i eth0 -w results.tcpdump ip6
>
> this will run as much as you want, and  will print how many packets 
> has it got, once in a while.
>
> when you have enough, you stop it with ^C, and go and watch the 
> results of the capture via wireshark, or ethereal or any other 
> graphical tool.
>
> regards.
>
>
>
>
>
>> cvs [login aborted]: connect to 
>> neutralino.physics.uiowa.edu(128.255.34.167):2401 failed: No route to 
>> host
>>
>> message. telnet is also giving similar problem:
>>
>> telnet  neutralino.physics.uiowa.edu 2401
>> Trying 128.255.34.167...
>> telnet: Unable to connect to remote host: No route to host
>>
>> :
>>
>>
>> Maxim kovgan wrote:
>>> Can you try and capture any ipv6 packets trying to leave your 
>>> computer when you're trying to login into cvs or to do other things 
>>> with cvs ?
>>>
>>>
>>> IF you find anything running, disable ipv6.
>>> (refer to your distribution's manual on how to do this.)
>>>
>>> Cheers.
>>>
>>>
>>>
>>>
>>> Taylan Yetkin wrote:
>>>> Hi,
>>>> ifconfig in the host returns:
>>>>
>>>> eth0      Link encap:Ethernet  HWaddr 00:19:D1:25:1F:C9
>>>>          inet addr:128.255.34.167  Bcast:128.255.35.255  
>>>> Mask:255.255.252.0
>>>>          inet6 addr: fe80::219:d1ff:fe25:1fc9/64 Scope:Link
>>>>          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>>>          RX packets:190785 errors:0 dropped:0 overruns:0 frame:0
>>>>          TX packets:55961 errors:0 dropped:0 overruns:0 carrier:0
>>>>          collisions:0 txqueuelen:100
>>>>          RX bytes:57983176 (55.2 MiB)  TX bytes:11357915 (10.8 MiB)
>>>>          Base address:0xecc0 Memory:dffe0000-e0000000
>>>>
>>>> lo        Link encap:Local Loopback
>>>>          inet addr:127.0.0.1  Mask:255.0.0.0
>>>>          inet6 addr: ::1/128 Scope:Host
>>>>          UP LOOPBACK RUNNING  MTU:16436  Metric:1
>>>>          RX packets:5670 errors:0 dropped:0 overruns:0 frame:0
>>>>          TX packets:5670 errors:0 dropped:0 overruns:0 carrier:0
>>>>          collisions:0 txqueuelen:0
>>>>          RX bytes:10405386 (9.9 MiB)  TX bytes:10405386 (9.9 MiB)
>>>>
>>>> while netstat -nr returns
>>>>
>>>>
>>>> Kernel IP routing table
>>>> Destination     Gateway         Genmask         Flags   MSS Window  
>>>> irtt Iface
>>>> 128.255.32.0    0.0.0.0         255.255.252.0   U         0 
>>>> 0          0 eth0
>>>> 169.254.0.0     0.0.0.0         255.255.0.0     U         0 
>>>> 0          0 eth0
>>>> 0.0.0.0         128.255.32.1    0.0.0.0         UG        0 
>>>> 0          0 eth0
>>>>
>>>>
>>>> Taylan
>>>>
>>>>
>>>>
>>>> Maxim kovgan wrote:
>>>>> Taylan Yetkin wrote:
>>>>>> Both ping and traceroute  the host from fermi machines returns  
>>>>>> success.  I need some time to understand the use of tcpdump.
>>>>>> thanks,
>>>>>> Taylan
>>>>>
>>>>> can you post your ifconfig of the listening interface ?
>>>>>
>>>>>
>>>>> a routing table would be nice too:
>>>>> netstat -nr
>>>>>
>>>>> you can of course scramble the IP addresses.
>>>>>
>>>>>
>>>>>
>>>>>>
>>>>>> Maxim kovgan wrote:
>>>>>>> John Summerfield wrote:
>>>>>>>> Maxim kovgan wrote:
>>>>>>>>> John Summerfield wrote:
>>>>>>>>>> Taylan Yetkin wrote:
>>>>>>>>>>> Hi,
>>>>>>>>>>> I installed a cvs repository in my local SL machine and 
>>>>>>>>>>> trying to connect
>>>>>>>>>>>  it
>>>>>>>>>>> from fermi machines. I get the following error:
>>>>>>>>>>>
>>>>>>>>>>> [cmswn085> cvs login
>>>>>>>>>>> Logging in to 
>>>>>>>>>>> :pserver:[log in to unmask]:2401/var/lib/
>>>>>>>>>>> cvsroot
>>>>>>>>>>> CVS password:
>>>>>>>>>>> cvs [login aborted]: connect to
>>>>>>>>>>> neutralino.physics.uiowa.edu(128.255.34.167):2401 failed: No 
>>>>>>>>>>> route to hos
>>>>>>>>>>> t
>>>>>>>>>>
>>>>>>>>>> This is a routing/firewall problem. the cvs command asks for 
>>>>>>>>>> the password before trying to connect.
>>>>>>>>>>
>>>>>>>>>> 07:02 [summer@numbat ~]$ cvs  -d 
>>>>>>>>>> :pserver:anoncvs@localhost:2401/var/lib/ login
>>>>>>>>>> Logging in to :pserver:anoncvs@localhost:2401/var/lib
>>>>>>>>>> CVS password:
>>>>>>>>>> cvs [login aborted]: connect to [localhost]:2401 failed: 
>>>>>>>>>> Connection refused
>>>>>>>>>> 07:03 [summer@numbat ~]$
>>>>>>>>>
>>>>>>>>> It's most probably tcpwrappers
>>>>>>>>
>>>>>>>> No. That allows a connexion, then rejects it. You don't get "no 
>>>>>>>> route" or "refused messages."
>>>>>>>
>>>>>>> AFAIK tcpwrappers refuse too.
>>>>>>> but I somehow missed the no route to.. :)
>>>>>>> and you're right! it needs some investigation:
>>>>>>>
>>>>>>> 1. ping to the host
>>>>>>> 2. traceroute to the host.
>>>>>>>
>>>>>>> if you sporadically get the no route problem, it means you have 
>>>>>>> ... a routing problem :)
>>>>>>>
>>>>>>> after you finished up with it, you can continue and trouble shoot.
>>>>>>> routing problem can be cause by your university/enterprise 
>>>>>>> firewall too.
>>>>>>>
>>>>>>>
>>>>>>> you can also investigate with tcpdump, which is a great sniffer.
>>>>>>>
>>>>>>> Good luck!
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>
>>>>>>>> "reset" is more probable.
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>
>
>