Can not ping my own lan1

[Mark2010_1]

Hello,

We have 2 LAN cards on our K box (HP UX 10.2). Lan0 and Lan1. Lan0 is on the extension bus and lan1 on Core IO. Both are 10Mbps.

After a failure on Lan0, we have disabled that card and enabled lan1 with the same IP, Netmask, Broadcast etc.

We changed, netconf and via sam we diabled lan0.

Now with netstat, we can see that default route is via lan1 (gateway still the same) as we were expecting.

How ever, very strange behaviour is happening

- Ping from K server to GW is NOK
- Ping from Gateway to K server is OK
- Ping from K server to it own lan1 is NOK
- getip servername is NOK
- NIS server not responding message (cause the server is set as NIS master).
- Tried with a cross-cable from server to my PC and get same behaviour GW-server.
- Restarted the server many times: same thing !

Well, I did not do any thing, just swapped the LAN from lan0 to lan1 !!!


Personally, Would be happy to get any help or idea.

[Bill Costigan]

what is the output of netstat -in and netstat -rn?

It almost sounds like some other device has your IP. The GW is pinging that device and not yours. Your I/F in down.

[Mark2010_1]

Hi Bill,

The I/F is UP, seen via ifconfig lan1.

I did also, the test via Server-MyLaptop and cross cable, so no other device.

The result is the same. Mylaptop ping the server BUT the server can not ping the laptop.

[Bill Costigan]

After doing a ping from your laptop, do an arp -a and see if the IP address for the server's IP is the same as what you see when you do a lanscan on the server.

Are you pinging by IP address or name?
Is the laptop and server on the same subnet?

[Mark2010_1]

Hi,

I tried arp -a ==> No thing, the command does not display any thing (like if it is hanging).

I am pinging using IP address.

the laptop and server are on the same subnet/vlan connected via cross cable.

[Mark2010_1]

- Another remark, before I was able to use Telnet on this server (telnet from a machine to this server). Now the telnet gives me: connction refused.

I tried a telnet locally on the server, the system says "unknown service".

I am wondering if it is an rpcd problem and how to fix it...

- From my laptop, I can not telnet to server but can make rlogin (take a while..).

But still can not ping my lan1 locally on the server :-(

[Bill Costigan]

I'm not quite sure how you have this cabled.

Are you saying that you simply have a cross over cable from the desktop to the server - not switches, hubs, etc. ?

If so, you might be having a duplex problem. One side thinks its full duplx and the other thinks it's half duplex.

Telent doesn't use rcp so that shouldn't matter.

What does landiag show for lan1? status and error counters.

[Hein van den Heuvel]

We had just one or two crossover cable in our 100+ system lab, and we guarded those carefulle, but never needed them for years.
It seemed to much clearer/easier to use hubs and switches. And now Gb ethernet is self sensing anyway.

Anyway...

Is lan.0 still cabled in?

What about the green/orange lights on the interface(s)?

Full-Duplex vs half was a good suggestion to check.
Same for the speed... 10mbps is rare in most environments I know.

fwiw,
Hein.

[Mark2010_1]

Hello,

What I can not understand is:

- Why my laptop can ping the server
- The server can not ping the laptop

While I tried the two machines with a cross cable (no firewall, no access-list..) and also with a small lan.

Why for instance arp -a does not show any thing on the server ?

BR

[F Verschuren · Accepted solution]

Hi,
can you replay your
netstat -rn just to rull out routing problems.

can you check you cart if it is able to reatch it self Here is a examble how:

[nlxsms01:nl11588:/home/nl11588]# lanscan
Hardware Station Crd Hdw Net-Interface NM MAC HP-DLPI DLPI
Path Address In# State NamePPA ID Type Support Mjr#
0/0/0/0 0x00306E09C152 0 UP lan0 snap0 1 ETHER Yes 119
[nlxsms01:nl11588:/home/nl11588]# linkloop -i 0 0x00306E09C152
Link connectivity to LAN station: 0x00306E09C152
-- OK
[nlxsms01:nl11588:/home/nl11588]#

[Mark2010_1]

Thanks F Verschuren for the linkloop :-)

BR