[Info-vax] tcpip gateway question

Anton Shterenlikht mexas at bristol.ac.uk
Tue Sep 8 09:25:49 EDT 2009


On Tue, Sep 08, 2009 at 06:05:35AM -0700, jbriggs444 wrote:
> On Sep 8, 8:30 am, Anton Shterenlikht <me... at bristol.ac.uk> wrote:
> > On Tue, Sep 08, 2009 at 04:37:25AM -0700, H Vlems wrote:
> > > On 8 sep, 12:31, Anton Shterenlikht <me... at bristol.ac.uk> wrote:
> > > > I've a VMS cluster on a local 10.10.10.0/24 network.
> >
> > > > I'm trying to set up one of the VMS nodes
> > > > to also sit on the University network 137.222.0.0/16.
> >
> > > > So I used tcpip$config and configured the two interfaces as:
> >
> > > >    1  -  WE0 Menu (EWA0: TwistedPair 100mbps)
> > > >    2  -  137.222.187.238/16  mech-cluster238       Configured,Active          
> >
> > > >    3  -  WE1 Menu (EWB0: TwistedPair 100mbps)
> > > >    4  -  10.10.10.1/24       vav                   Configured,Active          
> >
> > > > I added the default University gateway, 137.222.187.250, and
> > > > name servers 137.222.10.36 and 137.222.10.39 with tcpip$config
> > > > options
> > > >                  3  -  Routing              
> > > >                  4  -  BIND Resolver        
> >
> > > > I've ssh server and client enabled on this node.
> >
> > > > My problem is that I cannot even ping the gateway.
> 
> Which is a big problem.
> 
> >
> > > > Does this look reasonable:
> >
> > > > $ tcpip show route
> >
> > > >                              DYNAMIC
> >
> > > > Type           Destination                           Gateway
> >
> > > > AN    0.0.0.0                               137.222.187.250
> > > > AN    10.10.10.0/24                         10.10.10.1
> > > > AH    10.10.10.1                            10.10.10.1
> > > > AH    127.0.0.1                             127.0.0.1
> > > > AN    137.222.0.0/16                        137.222.187.238
> > > > AH    137.222.187.238                       137.222.187.238
> > > > $
> >
> [snip]
> > > Anton,
> > > the 10.10.10.0 network is reachable with this configuration?
> > > What is the output of:  traceroute 137.222.187.250?
> >
> > Hans,
> >
> > yes, 10.10.10.0 network seems to be completely fine. I can
> > connect to any node with ssh and ping any local node from any node
> > on the local network, e.g.:
> >
> > $ ping 10.10.10.8
> > PING 10.10.10.8 (10.10.10.8): 56 data bytes
> > 64 bytes from 10.10.10.8: icmp_seq=0 ttl=64 time=1 ms
> > 64 bytes from 10.10.10.8: icmp_seq=1 ttl=64 time=0 ms
> > 64 bytes from 10.10.10.8: icmp_seq=2 ttl=64 time=0 ms
> > 64 bytes from 10.10.10.8: icmp_seq=3 ttl=64 time=0 ms
> >
> > ----10.10.10.8 PING Statistics----
> > 4 packets transmitted, 4 packets received, 0% packet loss
> > round-trip (ms)  min/avg/max = 0/0/1 ms
> > $ ping 10.10.10.31
> > PING 10.10.10.31 (10.10.10.31): 56 data bytes
> > 64 bytes from 10.10.10.31: icmp_seq=0 ttl=64 time=0 ms
> > 64 bytes from 10.10.10.31: icmp_seq=1 ttl=64 time=0 ms
> > 64 bytes from 10.10.10.31: icmp_seq=2 ttl=64 time=0 ms
> > 64 bytes from 10.10.10.31: icmp_seq=3 ttl=64 time=0 ms
> >
> > ----10.10.10.31 PING Statistics----
> > 4 packets transmitted, 4 packets received, 0% packet loss
> > round-trip (ms)  min/avg/max = 0/0/0 ms
> > $
> >
> > But trying to reach the gateway I end up with this:
> >
> > $ tcpip traceroute 137.222.187.250
> > traceroute to vav (137.222.187.250): 1-30 hops, 38 byte packets
> >  1  * * *
> >  2  * * *
> >  3  * * *
> >  4  * * *
> >  5  * * *
> >  6  * * *
> >  7  * * *
> >  8  * * *
> >  9  * * *
> > 10  * * *
> > 11  * * *
> > 12  * * *
> > 13  * * *
> > 14
> >  Cancel
> >
> > (interrupt)
> > $
> >
> > the process doesn't seem to end, so I terminated it.
> 
> As indicated on the first line, that's a 30 hop traceroute.  It would
> have gone another 16 hops if you had not interrupted it.
> 
> The key observation is that the very first hop timed out.  You have no
> connectivity to the default gateway on the University side.
> 
> Your IP is 137.222.187.238
> gateway IP is 137.222.187.250
> 
> That means that the netmask is unlikely to be the culprit.  With two
> IP addresses that close to one another, the netmask on the default
> gateway would have to be 255.255.255.240 or narrower to cause
> problems.
> 
> http://h71000.www7.hp.com/doc/732final/6631/6631pro_001.html
> 
> Check interface status with tcpip> ifconfig -a


TCPIP> ifconfig -a
LO0: flags=100c89<UP,LOOPBACK,NOARP,MULTICAST,SIMPLEX,NOCHECKSUM>
     inet 127.0.0.1 netmask ff000000 ipmtu 4096 

TN0: flags=80<NOARP>

TN1: flags=80<NOARP>

WE0: flags=c43<UP,BROADCAST,RUNNING,MULTICAST,SIMPLEX>
    *inet 137.222.187.238 netmask ffffff00 broadcast 137.222.255.255 ipmtu 1500 

WE1: flags=c43<UP,BROADCAST,RUNNING,MULTICAST,SIMPLEX>
    *inet 10.10.10.1 netmask ffffff00 broadcast 137.222.255.255 ipmtu 1500 

TCPIP> 

bcast on WE1 seems to be wrong.. 


> Check ARP with $ tcpip show arp

TCPIP> show arp
Cnt  Flags    Timer Host                     Phys Addr
  1: UCS        912 10.10.10.8               aa-00-04-00-03-08
  2: UCS        893 10.10.10.9               08-00-2b-87-41-f9
  3: UCS        943 10.10.10.31              00-11-0a-31-d6-ec
TCPIP> 

> If you don't see any ARP entries on the University side, that's a clue
> that you're not receiving from it.

I guess I'm not receiving from it..

> Have someone log onto the gateway and see if they see your ARP.  If
> not, that's a clue that it's not receiving from you.
> 
> You don't have a duplicate IP address (137.222.187.238) do you?  You
> didn't steal it from the FreeBSD box by any chance?

I don't think so. This ip address has been with this interface for 
several years now (it was a stand-alone box). Running nmap 137.222.187.238
from other boxes doesn't find any other nodes.

I'll change the Ethernet cable just in case..

many thanks


-- 
Anton Shterenlikht
Room 2.6, Queen's Building
Mech Eng Dept
Bristol University
University Walk, Bristol BS8 1TR, UK
Tel: +44 (0)117 331 5944
Fax: +44 (0)117 331 5924




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