Network problem

[Esteban Cordero]

I have a network problem with HP-UX 11iV2 on an RX2600. I can see other machines on the network at a Mac Address level, but when I try to stablish contact on layer 3 conectivity, it doesn't work, if I try to ping other machines, the first package returns, but after the first one, the contact is lost, no response from the other machines.

[Bryan D. Quinn]

It kind of sounds like an IP address conflict to me.

First thing I would try is to shutdown your machine and then go to another box and try to ping it's address. Just to make sure you don't have some other piece of hardware out there with the same IP address as your box.

If you box is down and it's IP pings from another box, then you need to find out why that is and change one of the IP addresses.

Next, I would check your port settings. Make sure you are full duplex at your network card and at the switch/hub that the box is plugged into.

Hope this helps!
-Bryan

[Esteban Cordero]

I'm positive it's not an IP conflict.. I checked just in case, and there's not another machine with that IP address, I have checked the speeds and both the Switch and the NIC are set for 100 Mbps FD. It's really strange, the first packed returns, then the conection is lost. If I unplug and plug the LAN cable, I get another package and the conection is lost again.

[doug mielke]

I'll assume that you can see the arp table
arp -a., and that you don't have 2 cards trying to use the same ip segmant.
( You will only see systems on you're local segment.)

Check that they are not changing mac addresses when you try pings, and that they are complete with IP adress.

If okay, or you're trying off the local segment, try
traceroute address
if it doesn't complete, look for a routing error with
netstat -r
if it completes, then look at your netmask. If okay, I'd ask for help from the network / router folks on your site to ensure that pings are allowed, routes are in place, recommended default gateway, etc.

[Norman_21]

Hello,

Try to swapout the LAN cable, maybe you have a bad one. Also, are you able to ping from other machines. Check all the physical connectivity between your machines in your LAN!
#lanadmin -x x [where x is your lan card number]

USe stm to diagnos your LAN card
#cstm
cstm>sel path
cstm>info;wait
cstm>il

Hope this help

[Esteban Cordero]

Thanks for the suggestions. I sure can see the ARP table and I can see the other machines on my local network, the problem comes when trying to ping any of them. If I try traceroute before pinging, then it works, but just once.. It's the same as the ping, it would only work for the first package. It can't be a routing problem because they're all in the same LAN, but I'll double check with netstat. Netmask is fine. There aren't restrictions for ICMP packets in the switch, or the machines.. The other machines can ping each other just fine. But they can't ping the RX2600 at all, not even the first package. The cable is Ok with another machine, and I have tried swapping cables just in case. I'll try stm now and see what happens. Thanks again for the suggestions.

[Ron Kinner]

lanadmin
lan
display

does everything look OK? Do you see a lot of errors on the second page?

netstat -s

do you see anything suspicious?

Can it ping its own IP address or 127.0.0.1?

Did you try plugging it into a working port? Connect it to another PC from the same subnet with just a crossover cable to eliminate any switch problems?

Are your ARPA patches uptodate? This is starting to smell like a software bug.

Ron

[Norman_21]

Hello again,

Is the settings in your /etc/rc.config.d/netconf correct?
you may copy a new config file:

#mv /etc/rc.config.d/netconf /tmp/netconf.org
#cp /usr/newconfig/etc/rc.config.d/netconf /etc/rc.config.d/
then change the configuration accordingly

Hope this help!

[Berlene Herren]

Format your nettl log and see if errors are being reported there.

netfmt -f /var/adm/nettl.LOG000 > /tmp/net.out

Berlene

[Duncan Edmonstone]

Its odd that you get one reply, and then none - I wonder if a router is sending out bad ICMP redirects? Can you also post your routing tables (netstat -rn)

HTH

Duncan

[Elmar P. Kolkman]

Also: the other machines, are they within your netmask or are the on a virtual other LAN?
In that case it could be your default router is not pingable, which can result in this behaviour... This can be fixed using:
ndd /dev/ip -set ip_ire_gw_probe 0