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Re: network connectivity problem

 
Edgar_8
Regular Advisor

network connectivity problem

Hi,

We have completed an HP-UX 11i install but the server fails to be seen/connect on the network. The IP;Gateway ; subnetmask is correct in the netconf files but still no connectivity. The server has 2 NICs:
lan1 - ethernet 10/100bt
lan2 - gigabit 1000

Any possible reasons for network connectivity connection problems?

Thanks!
7 REPLIES 7
Mark Grant
Honored Contributor

Re: network connectivity problem

One "gotcha" that I see quite a lot on new installs with multiple lan cards is when the network cable is in the wrong card and therefore the patching is wrong.

However, assuming the cable is OK then check routing "netstat -rn"

Also, try and ping "localhost" to make sure that there is no fundamental tcp problem.

Never preceed any demonstration with anything more predictive than "watch this"
Rajeev  Shukla
Honored Contributor

Re: network connectivity problem

Hi,
Login to the console of the server, do a netstat -in and see that you have right IP address assigned to the lan interfaces, i mean to see if the cables are pluged in right network for the respective interfaces. Ping the local host, ping the gateway, if none work, try low level ping which is linkloop. Which works on the MAC level, have a look at the man pages of linkloop and try pinging other interfaces...
By the way first verify you have link lights glowing on the interfaces on the server.
Sunil Sharma_1
Honored Contributor

Re: network connectivity problem

Hi,

why don't you use linklook to check H/W level connectivity?

for more info check man linkloop


Sunil
*** Dream as if you'll live forever. Live as if you'll die today ***
Edgar_8
Regular Advisor

Re: network connectivity problem

Hi,

If we ping the localhost we get a reply, but any server on the network cant be reached,including the default gateway! All the cables are connected & netconf is set-up correct. Any ideas would be most appreciated!
Zigor Buruaga
Esteemed Contributor

Re: network connectivity problem

Hi,

Run "netstat -in" and see if there is any asterisk near the interfaces name.
Check also with "ifconfig lanX" ( where X is 0,1, etc ) that the interfaces are up and correctly configured. For example when I run "ifconfig lan1" I see:
lan1: flags=843

Try also, as suggested, with "linkloop":
# linkloop -v 0x"nic_mac_address"
( You can go to other HP-UX server and run "lanscan". In the output you will see the column "Station Address", use that value ( i.e. 0x08000930A4B4 ) in the linkloop command ).

HTH
Kind regards,
Zigor
Fabio Ettore
Honored Contributor

Re: network connectivity problem

Hi Edgar,

what is IP address of your system and gateway configured in netconf?
I aks you this question because if they are not on the same subnet then problem could be that.

Just a thought...

Best regards,
Ettore
WISH? IMPROVEMENT!
Ron Kinner
Honored Contributor

Re: network connectivity problem

Pinging your own IP proves nothing since the box will recognize it and never send it out on the wire. Instead try:

lanadmin
lan
display

first couple of line will tell you if the NIC is properly programmed and if it is working. You should see two UPs. Disconnect the network cable to verify you are looking at the one you think you are. You should lose one of your UPs.

ppa 1
or maybe ppa 2
depending upon what the first display showed for ppa (+1) will let you run display on the second NIC.

You can also try
lanscan

linkloop is a good test for level 2 connectivity but can only be trusted with other HP hosts. You must specify which interface to use since you have two.

linkloop [-i PPA] [-n count] [-r rif] [-s size] [-t timeout] [-v] linkaddr ...


If your IP address is the first or last subnet then turn off subnet checking in ndd.


ndd -set /dev/ip ip_check_subnet_addr 0

will do it for now but you need to put it in nddconf in order for it to be remembered at boot.

edit /etc/rc.config.d/nddconf to add:

TRANSPORT_NAME[0]=ip
NDD_NAME[0]=ip_check_subnet_addr
NDD_VALUE[0]=0

If there is already an entry then you have to change the numbers in brackets to the next higher number.



If your gateway does not want to answer pings then turn off dead gateway detection with ndd.

ndd -set /dev/ip ip_ire_gw_probe 0

Also add the entries into /etc/rc.config.d/nddconf file to permanently disable dead gateway detection.

TRANSPORT_NAME[1]=ip
NDD_NAME[1]=ip_ire_gw_probe
NDD_VALUE[1]=0


You may have to remove the gateway and reenter it to get it out of dead status.

Ron